project agreementctis.utep.edu/training_s/links/txdot_0-5566_proposal.doc · web viewproject...

Exhibit B

PROJECT DESCRIPTION

Project Abstract

Many rural intersections originally constructed with thin untreated flexible base and hot mix or a two-course surface treatment experience severe pushing, shoving and rutting. These failures cause an extremely rough surface that can cause damage to small vehicles and potentially cause motorists to loose control of their vehicle. These distresses almost always result in complete failure of the existing pavement that must be repaired several times during the life of the roadway by maintenance forces. Pavement sections constructed with the same materials adjacent to the intersection perform adequately until the approach (approximately 150 ft in advance) of the intersection and in the intersection itself when the failures become apparent.

This project would seek to understand the mechanisms of intersection pavement failures and determine the best practices to minimize the failures at existing intersection pavements. The outcome of this project should help to reduce the frequency of maintenance needed at rural intersections. This project would also determine how the mechanisms causing the surface failures at intersections can be mitigated through design and construction modifications.

Background and Significance of Work

A vast majority of the TxDOT highway system consists of secondary roads that are constructed with thin pavement structures and thin hot mix asphalt surface or two-course surface treatment. This network of low-volume roads has served the public well, and for the most part, performs satisfactorily with periodic maintenance. One of the weakest links in this network is the performance of the pavement at the intersections. Severe permanent deformation (pushing, shoving and rutting1) have been reported at intersections of some of these low-volume roads while pavement sections constructed with the same materials adjacent to the intersection perform adequately. These failures occur because of the higher severity of loads exerted to the pavement at the intersections.

An extensive review of the literature indicates that the sources of and solutions for failure of the intersections in urban areas are well researched and a number of solutions (such as full-depth concrete slabs, white topping, high quality hot mix asphalt) have been implemented. For example, the National Asphalt Pavement Association (NAPA) and the American Concrete Pavement Association (ACPA) have several documents and training materials available for this purpose. Little attention has been focused towards the rural low-volume road intersections in the US. A vast body of knowledge, however, is available from work done in other countries (e.g., Africa, Southeast Asia, Australia and New Zealand) where the majority of their highway networks are either unpaved or are only covered with surface treatment. The primary motivation for reconstruction or rehabilitation of the urban high-volume intersections is the speed of the operation to minimize the road closure, and economy of the solution is of the secondary consideration. However, to develop implementable solutions for the rural intersections, the economy of the solution plays a primary role. The primary goal of this project is to provide solutions that can be readily and economically carried out considering the location of the project, the construction practices, and the type of potential or actual damage at the intersection.

1 In this proposal the term permanent deformation is used to imply to rutting as well as shoving and pushing.

Project 0-5566 of 24

Exhibit B

Based on this background, our goals in this project are to achieve the following items:

1. Document the types of distress that are present in the field throughout Texas through surveys and site visits.

2. Categorize the sources and layers that contribute to the damage at intersections.3. Select a number of statistically-valid, representative intersections of each category in Item 24. Evaluate selected locations to define the best solutions5. Develop maintenance and rehabilitation guidelines for intersections with problems6. Develop (minimum) pavement design for rural and urban intersections7. Develop draft specifications for flexible pavement construction for rural intersections.

Since the sources of excessive permanent deformation of intersection and the possible solutions are diverse, we propose to incorporate the knowledge gained into an easy-to-use Expert System software package. The Expert System will provide step-by-step guidance on the process of identifying the sources of the problem, and designing the optimum pavement intersection structure to mitigate the problem. It will also serve as a design tool for pavement designers as well as a training tool for new or inexperienced engineers.

The University of Texas at El Paso (UTEP) respectfully submits this proposal to address the issues summarized above. The work will be supervised and carried out by experienced research engineers and faculty with strong background in pavement design, laboratory and field testing, and material characterization. Dr. Nazarian, which will act as the Research Supervisor (RS) of the project, has extensive background in pavement analysis and design as well as lab and field testing. He participated in many forensic studies of TxDOT. Before completing his graduate studies, Dr. Nazarian worked as a construction engineer. Mr. Imad Abdallah will head the development of the expert system. Dr. Deren Yuan will assist the team in field testing and pavement evaluation. Mr. Jose Garibay, as the Lab Manager of pavement facilities at UTEP, will lead the required laboratory testing.

It is understood by the team that given the diversity of the subgrade types, environmental conditions, volume of traffic and the existing pavement structures, the solutions proposed may be diverse. The body of evidence from other countries with vast network of low-volume roads indicates that the most economical and effective solutions are those that strengthen the shallow subgrade or base instead of adding layers of hot mix or concrete. As such, UTEP team will do their best to minimize the use of high-performance hot mix and concrete in the solutions. To that end, the team will build on several TxDOT projects dealing with the design of low-volume roads and construction of bases and subgrades with additives. Many lessons learned in those projects can be directly applied to this project. These projects include:

Project 0-5430: “Realistic Design Guidelines for Low Classification Roads in High PI Clays,” (to be completed in August 2008). The main objective of that research is to develop an expert system that provides more realistic design approach for low-volume roads in areas with expansive subgrade soils. Current design procedures used in Texas often yield a thick pavement structure to minimize the impacts of the expansive subgrade soils. But these pavements often fail prematurely. As part of this research the design and laboratory procedures to address expansive subsoil conditions and then design pavements accordingly to extend the life expectancy of these roads have been developed. The outcome of that project can directly be used in this study for structural evaluation of the sections in this study.


Exhibit B

Project 0-4519 (in partnership with TTI): “Verification of the Modified Triaxial Design Procedure,” (completed in August 2005). In that project the current Texas Triaxial design method for low-volume roads was critically evaluated. A new method for estimating the damage to low-volume roads that consider the environmental condition in terms of precipitation and type of subgrade was also developed. The outcome of that project can also directly be used in this study for structural evaluation of the sections.

Project 0-5562: “Guidelines for Using Local Materials for Roadway Base and Subbase,” (to be completed in August 2008). In that project, economical strategies for utilizing out of specification local bases instead of hauling high-quality bases from distant quarries have been developed. Those strategies, primarily based on light stabilization of local materials, can be adapted to address the objectives of this project.

Project 0-5569: “Accelerated Stabilization Design” (to be completed in August 2008). In that project it has been found that the moisture conditioning with capillary saturation or Tube Suction Test may not be adequate for assessing long-term performance of the stabilized materials. Recommendations in terms of rapid methods for assessing the long-term performance of stabilized materials have been made in that study that will be quite relevant to this project.

Project 0-5797: “Design, Constructability Review and Performance of Dual Base Stabilizer Applications,” (to be completed in August 2008). In that project a design process for stabilizing bases with emulsion with and without calcium-based additives is recommended. The outcome of this project, especially lessons learned during construction, can also be used in this study.

Project 0-5223: “The Effects of Pulverization on Flexible Pavement Design Procedures,” (completed in August 2007). In that study the impact of the change in the gradation of the mixes on their performance was studied. The findings from that project are quite relevant to this study since full-depth reclamation may be an option in this study.

Review of the Literature

A flowchart of the desirable activities necessary to address the rutting problem of the intersections, borrowed from a concerted national effort by the Federation of Canadian Municipalities and Canadian National Research Council (2003)2. is included in Figure 1. This flow chart is a good road map for executing the tasks proposed in this project.

Process for Mitigating Rutting

The key to achieving the desired performance of flexible pavements at intersections, with their severe loading conditions, is recognizing that intersections may need to be specified, designed, and constructed differently than regular asphalt pavements. One of the significant aspects of this project is to decide how to design and rehabilitate the intersections that is economical. According to the Canadian nationwide guideline to mitigate permanent deformation at intersections2, the intersection pavement rut mitigation action plan should involve the following four key steps:

2 Federation of Canadian Municipalities and Canadian National Research Council (2003) “Rut Mitigation Techniques at Intersections,” http://www.sustainablecommunities.fcm.ca/files/Infraguide/Roads_and_Sidewalks/rut_mitigation_techn_intersections_.pdf


http://www.sustainablecommunities.fcm.ca/files/Infraguide/Roads_and_Sidewalks/rut_mitigation_techn_intersections_.pdf


Exhibit B

Figure 1 – Flowchart of Activities for Mitigating Intersection Rutting


Exhibit B

1. Evaluate pavement performance problems and determine the cause of any rutting.2. Ensure the pavement is structurally adequate.3. Select and implement a cost-effective, technically sound pavement rut mitigation approach

with appropriate materials selection and mix designs.4. Practice proper construction techniques with quality assurance.

These steps are described further below.

1. Evaluate Pavement Performance Problems and Determine Cause of Any Rutting

The two basic types of intersection rutting and their potential causes, as shown in Figure 2, consist of the following (combination of these two is also possible): (1) Structural rutting, and (2) Instability rutting (permanent deformation of the asphalt concrete).

The most perseverant mode of failure for low-volume roads in Texas (especially with two-course surface treatment) is the structural rutting. For those rural roads covered with HMA, the instability rutting may also be of concern. Structural rutting requires a detailed pavement design evaluation and then addressing the causes (loadings, weak subgrade or base, poor drainage, etc.) through pavement reconstruction to a proper pavement structure design.

The instability rutting of asphalt concrete is sometimes triggered by heavy traffic wheel path densification (often with flushing), that results in low air voids, sustained higher surface temperature and reduced shear strength. This results in rutting through shear deformation. Three cases of asphalt concrete instability rutting are: (1) immediate (problems with HMA mix design, or construction quality); (2) slow (marginal HMA resistance to rutting with progressive permanent deformation); and (3) triggered (some change that increases the wheel loading stresses, such as detour road use with trucks or new construction activity in the region).

Figure 2 – Most Common Types of Rutting at Intersections


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0 1 2 3 4 5 6 7 8No. of Single Axle Trucks, million

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a) Raw Material Base: 28 ksi/18 in. Subgrade: 20 psi

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b) Treated with 1% Lime Base: 138 ksi/14 in. Subgrade: 20 ksi

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a) Raw Material Base: 28 ksi/18 in. Subgrade: 20 psi

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0 1 2 3 4 5 6 7 8No. of Single Axle Trucks, million

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b) Treated with 1% Lime Base: 138 ksi/14 in. Subgrade: 20 ksi

Exhibit B

Therefore, it is of utmost importance to identify the layer(s) that contribute to the excessive permanent deformation of the intersections. The evaluation of any roadway for this purpose should include:

visual inspection of surface condition (e.g., raveling or bleeding) and transverse profile measurements

deflection testing to check for structural adequacy; coring to obtain samples of the pavement materials and subgrade for laboratory examination; thickness measurements of all pavement layers, in both rutted and non-rutted areas; determination of material properties of the subgrade (type, moisture condition, plasticity

index, and strength), base (type, thickness, moisture condition, density, gradation, and strength), asphalt concrete (thickness, air voids, gradation and asphalt content, etc.)

a review of the construction and maintenance information, with a focus on the overall quality of construction.

The findings are then analyzed to determine the type(s) of rutting that hav occurred and its causes, to recommend the most appropriate rut mitigation strategy from pavement preservation to overlay to rehabilitation to reconstruction (see Figure 1). The type of activities to be carried out to rectify the problem can be categorized as following items

pavement preservation (e.g., with low severity instability rutting); pavement overlay (e.g., with medium severity instability rutting); pavement rehabilitation (e.g., with high severity instability rutting); or pavement reconstruction (e.g., with pavement structural rutting).

2) Ensure Pavement is Structurally Adequate

The current pavement design process in TxDOT is based on FPS19, and Texas Triaxial Design methods. For assessing rutting, these two methods ensure that the thickness of the base and HMA are adequate to minimize the rutting of subgrade. Neither one of these two methods can provide insight on the rutting of the base and HMA. A program called VESYS has been developed by the FHWA and to some extent calibrated by TTI and UTEP can be used to estimate the contribution of each layer to rutting. UTEP team has utilized VESYS extensively in Project 0-5562 dealing with economical use of local bases. As an example, Figure 3 compares the rutting contributions of the base and subgrade with load repetition for a granular base material

Figure 3 - Estimated Rutting Depth of a Lubbock Material with Raw and Treated Bases


Exhibit B

from Lubbock and the same material treated with lime. Most of the rutting (about 90% of total) happens in the base course if 18 in. of raw base is used, whereas, for 14 in. of the same material treated with lime, only less than 5% of the total rutting is in the base course. Also, the total pavement rutting with the treated base is one magnitude less than that with the untreated base. The results from the VESYS were validated with a number of tests as summarized in Table 1. Tests were carried out on a small-scale (3-ft diameter) specimen where the base and subgrade were placed carefully at their respective optimum moisture contents. Table 1 clearly demonstrates that improving the base by stabilization with small amount of additives improved the performance of the section significantly. This table also clearly indicates the importance of considering a number of parameters for suggesting the appropriate solution for rutting of intersections, namely: the type of subgrade, the moisture condition of the base and subgrade, and the properties of the base and subgrade. The lessons learned by the UTEP team in Project 0-5562 can be readily translated in providing guidelines for low cost rehabilitation of intersection to mitigate rutting.

Table 1 – Permanent Deformation of Lubbock Material from Small-Scale Tests

Moisture Condition

No. of Cycles to 200 mils Permanent Deformation

No Additives With Lime

Sandy SG Clay SG Sandy SG Clay SG

Optimum >5000 >5000 >5000 >5000

Subgrade Saturated >5000 1900 >5000 N/A

Subgrade-Base Saturated 268 72 3000 1300

Another important factor is the loads applied to the intersections. The intersections are subjected to heavy, slow-moving, channeled traffic. These locations can also be subjected to severe braking, standing, accelerating, turning, where lateral stresses are applied. Harsher conditions, such as vehicle drippings, exhaust heat and cross-traffic load repetitions also apply to intersections. This problem is aggravated at higher pavement temperatures where the stiffness of HMA is further decreased. The higher than normal shear and horizontal forces, which are typically ignored, are of utmost importance in the safe operation of the airfields, especially at the junctions of taxiways and runways and in the airfield parking lots. The Army Corps of Engineers provide guidelines for this problem under their Pavement-Transportation Computer Assisted Structural Engineering (PCASE3) program. The lessons learned from airfield pavement design can be translated into the problem of permanent deformations of the intersections.

3) Select and Implement Cost-Effective, Technically Sound Pavement Rut Mitigation Approaches with Appropriate Materials Selection and Mix Designs.

Quoting directly from TxDOT design guide:Pavement performance can be largely attributed to the performance of its foundation, which is comprised of the subgrade and base layers. Base and subgrade layers must provide the following:

Shear strength – ability to resist shear stresses developed as a result of traffic loading;

3 https://transportation.wes.army.mil/triservice/pcase/


https://transportation.wes.army.mil/triservice/pcase/

Exhibit B

Modulus (stiffness) – ability to respond elastically and minimize permanent deformation when subjected to traffic loading;

Resistance to moisture – the ability to resist the absorption of water, thus maintaining shear strength and modulus, and decreasing volumetric swell;

Stability – the ability to maintain its physical volume and mass when subjected to load, and

Durability – the ability to maintain material and engineering properties when exposed to environmental conditions such as moisture and temperature changes.

To include the above criteria in the mitigation of intersection permanent deformation, the answer cannot be based on the results of either laboratory tests or field results alone, but the problem should be considered as a system. Some of the parameters that play an important role in the system are the structural integrity of the section, the internal stability of the layer, the environmental conditions, the intended use (low-volume vs. high-volume roads), and of course the cost-benefit ratio of the selected strategy.

Structural Integrity: The structural integrity of a flexible pavement section is controlled by several parameters. In most classical structural design programs (such as FPS19 or Texas Triaxial), the design thickness of the layers are (directly or indirectly) estimated based on the criteria that the stresses at the interfaces of the hot mix and base and the base and subgrade are low enough so that the cracking and rutting will not be an issue. The traffic volume is also a major consideration. For a given traffic condition, the thicker the layers overlying the base, the thicker the base layer and the stiffer the subgrade are, the lower the base layer stresses will be. This indicates that not only the quality of the base and HMA should be considered in the remediation decision, the stiffness of the subgrade and the thickness and stiffness of the HMA should also be considered.

Internal Stability: In the context of this proposal, we define the internal stability as the excessive deformation of the subgrade, base or HMA under the load. To address this issue, repeated load permanent deformation lab tests as advocated by the Federal Highway Administration can be used in conjunction with the appropriate models (such as VESYS) that predicts the rutting of the HMA, base and subgrade layers individually.

Environmental Conditions: In the context of this proposal, the main environmental parameter of interest is the adverse effects of moisture on the strength and modulus of the base and subgrade layers and temperature on the HMA. Referring back to Table 1, when the tests were carried out at the optimum moisture conditions, more than 5000 cycles did not produced appreciable rutting. When water was introduced to the subgrade until it became saturated but the base maintained at the optimum, the specimens on clayey subgrade performed much worse, while those on the sandy subgrade performed adequately. Finally, when more water was introduced to even saturate the base, the specimen without additives in base layer on the clayey subgrade experienced more than 200 mils of rutting in 72 cycles. Therefore, the importance of considering the impact of moisture on the performance of the material should not be neglected. Two inter-related methods can be used to assess the impact of moisture on the performance of the base and subgrade materials: Tube Suction Test (Tex-145) and the Free-Free Resonant Column (Tex-149).

The Tube Suction Test (TST) qualitatively provides an estimate of the water-retention of the base material that can be correlated to the potential of damage to the base due to softening. The Free-Free Resonant Column (FFRC) test is a quantitative nondestructive lab method that can be


Exhibit B

performed on a specimen for its modulus. In both methods, each specimen is oven-dried for two days and then allowed to soak moisture through capillary saturation. The modulus of the specimen is measured every day in conjunction with the tube suction test. The residual modulus corresponds to the modulus measured after the specimen soaked moisture for several days. Since the same specimen is used throughout for both TST and FFRC tests, the variation in moisture content with time can also be obtained by weighing the specimens daily. In that manner, the moisture retention properties of the material and its impact on modulus can be measured. Of course separate specimens should be prepared and tested for strength and modulus at optimum and after moisture conditioning to determine the retained strength and retained modulus for conventional design.

Traffic Volume: It is understood that the focus of this project is primarily for the low-volume roads. It is also well understood that the volume of traffic impacts the structural design of the pavements in terms of thickness. What is of utmost importance but less understood, is that some construction practices and material selection processes that are quite reasonable for low-volume roads, may not be applicable to higher-volume roads because of the durability and the possibility of excessive maintenance, and vice versa. These parameters should also be considered.

Cost-Benefit Ratio: Life cycle cost analysis (LCCA) is a tool that helps transportation agencies in comparing the value or priority of competing projects from an economical analysis stand-point. The analysis employed by LCCA uses a controlled accounting of the effects of agency activities and allows incorporating and balances the impact of construction, rehabilitation, and preservation needs of the system.

Ozbay et al. (2004)4 present the product of a three-year study that assessed the life cycle cost analysis (LCCA) practice within the state highway agencies (SHAs). This work provides valuable insight in the development of LCCA methods. Salem et al. (2003)5 presents an approach for estimating life-cycle costs and evaluating infrastructure rehabilitation and construction alternatives, derived from probability theory and simulation application. A risk-based approach using probability theory and data input modeling to protect probabilities of occurrence of different life-cycle costs associated with the construction/rehabilitation of an infrastructure is used. This model is very relevant to this study given the uncertainty that exists in the pavement performance models, material characterization and the construction method. The Federal Highway Administration (FHWA, 2002)6 presents a primer on Life-Cycle Cost Analysis. The book outlines in detail the LCCA methodology for establishing design alternatives, determining activity timing, estimating costs, computing Life-Cycle costs and analyzing results. A software package called RealCost is also provided. This software is very flexible and can easily be adapted to the needs of this study.

Expert System: Often in selecting strategies to solve a problem, such as one proposed in this research study, several constraints and complex tasks are possible due to the large number of possible scenarios such as pavement materials and traffic data. A tool such as an Expert System can serve well to guide in the design process and provide an easy means for disseminating the

4 Ozbay, K., Jawad, D., Parker, N. A., and Hussain, S., (2004), “Life Cycle Cost Analysis: State-of-the-Practice vs. State-of-the-Art,” Conference Proceedings: 83rd Annual Meeting of the Transportation Research Board, National Academy of Science, Washington, D.C.5 Salem, O., AbouRizk, S., and Ariaratnam, S., (2003), “Risk-Based Life-Cycle Costing of Infrastructure Rehabilitation and Construction Alternatives,” Journal of Infrastructure Systems, Vol. 9, No. 1, pp. 6-15.6 Federal Highway Administration Office of Asset Management, (2002), “Life-Cycle Cost Analysis Primer”.


Exhibit B

knowledge and expertise of specific guidelines and practices to pavement managers and designers across the state. The expert system would serve as a look up table or catalog of strategies to provide informative and practical guide on the details of the design practice for intersections. A detailed explanation of the use of expert systems in the pavement engineering is summarized in UTEP Research Report 0-4188-17 and extensively used in Project 5430 in design of low volume roads on high-PI clays.

In the development environment, the knowledge, expertise, or set of rules and guidelines need to be developed into the knowledge base. Depending on the goal and use of the expert system, the knowledge can be accessed in a variety of ways such as from people, from books, manuals, guidelines, and protocols. The knowledge base includes the if-then rules and specifications where the information is stored. An inference engine implements the reasoning mechanism and controls the interview process. The inference engine might be generalized so that the same software is able to process many different knowledge bases.

4) Practice Proper Construction Techniques with Quality Assurance.

The performance of any pavement is highly dependent on the pavement construction techniques followed, and the quality of construction achieved. No matter how much care is taken with the selection and specification of pavement type, materials, and mix designs, the performance still depends on proper construction techniques and quality control. Due to the criticality of the intersections, perhaps more rigorous quality management should be applied to the intersections. Based on the field observations, the construction records, and our experience in performance-based quality control gained in Project 0-40468, we will address this issue.

7 Melchor O., Wanyan Y., Weissmann J. and Nazarian S. (2001) “Methods to Accelerate Construction of PCC Pavements: An Overview,” Research Report 0-4188-1, Center for Highway Materials Research, UTEP8 “A Tool for Estimating Impact of Construction Quality on Life Cycle Performance of Pavements,” Research Report 4046-4, UTEP, http://ctis.utep.edu/publications/Reports/0-4046-4.pdf


http://ctis.utep.edu/publications/Reports/0-4046-4.pdf

Exhibit B

Implementation

The failures of intersections is often a significant pavement performance problem requiring cost-effective, technically sound mitigation techniques. Truck heavy wheel loadings, particularly when slow moving or standing, and during hot weather, subject the pavement to stress/strain conditions, which may cause excessive permanent deformation. These high stress/strain conditions at intersections require these pavements to be designed, constructed, and maintained to withstand much more severe operating conditions than regular pavements. The products of the proposed research will include the guidelines for design and construction of intersections and a draft specification for the construction of intersections. An expert system will also be developed for TxDOT districts as an easy-to-use tool for selecting appropriate remedies at intersections. TxDOT could consider taking the products and conducting training-oriented presentations at a future annual construction and transportation conference.

Work Plan

The primary goal of this project is to provide solutions that can be readily and economically carried out to mitigate the excessive permanent deformation of intersections considering the location of the project, the construction practices of the roads, and the type of potential or actual damage at the intersection. A guideline and a draft specification for the design and construction of intersections will be provided. To achieve this goal, at a minimum, the following objectives have to be addressed:

1. Document the types of distress that are present in the field throughout Texas through surveys and site visits.

2. Categorize the sources and layers that contribute to the damage at intersections.3. Select a number of statistically-valid, representative intersections of each category in Item 24. Evaluate selected locations to define the best solutions5. Develop maintenance and rehabilitation guidelines for intersections with problems6. Develop (minimum) pavement design for rural and urban intersections7. Develop draft specifications for flexible pavement construction for rural intersections.

To address the objectives enumerated above, and to optimize the deliverables given the time and funding constraints, a two-year study is proposed. The project is further categorized into two phases. The first phase is dedicated to Objectives 1 through 4. In the second phase of the project, Objectives 5 through 7 will be addressed.

The flowchart in Figure 4 outlines the highlights of the nine tasks proposed and the anticipated outcome of each task. This flow chart demonstrates that the objectives of the projects can be met through a systematic effort. A detailed description of each task is provided in the next section.


Exhibit B

1. Information Search

2. Understanding and Documenting

Extent of Problems and

Solutions in Texas

3. Selection of Candidate Sites

for In-Depth Evaluation

4. Thorough Forensic Study of

Candidate Sites

5. Preliminary Guideline Based on Results from

Tasks 2 through 4

6. Develop Final Design and

Construction Guideline

• A comprehensive Literature Review

• Surveying Districts• Reviewing Forensic Reports• Interviewing District Personnel and site visits• Interviewing CST Personnel

• An in depth sta tistical and trend analysis of results from Task 2 to categorize typical problems

• Structural and Functional evaluation of sites • Coring and Sampling • Laboratory tests of Pavement Materials • Recommending solutions • Conducting thorough structural design of the existing and recommended Solutions• Life Cycle Cost Analysis of Solutions

• Develop a Comprehensive Decision tree- to guide TXDOT personnel through the

process of field and Laboratory evaluation intersections

- to select the most appropriate rehabilita tion solutions

• Incorporate the outcome of Task 5, the remaining outcome of field work and feedback from PMC in a final guideline

• A document of practices for mitigating rutting at intersections worldwide• A matrix of solutions, when they are effective, their advantages and disadvantages, their economical feasibility

• A document of typical intersections with problem• A cata log of sources of problems• A cata log of effective and ineffective solutions • A comparison of TxDOT solutions with those from other sta tes and countries

• At least twelve sites that cover the inference space of the problems, pavement types, environmental conditions, subgrade types etc. for in depth field and laboratory evaluation

• A cata log of solutions based on the type of the problem, and the field and laboratory testing results

• A flow chart that will lead TXDOT personnel through steps necessary for selecting best rehabilitation solutions for a given intersection

• A document that can be used as a guideline by TxDOTpersonnel• An electronic version of the document with hyperlinks that provide additional information to TxDOT personnel

Task Activity Highlights Work Product

7. Develop an Expert System

• Incorporate the outcome of Task 5 and 6 in an expert system shell to readily guide TxDOTpersonnel in determining the best solution

• A software that will ask a series of simple if-then questions from users to guide them through the process of selecting the best solution, determining the most appropriate mix or mineral, and suggestions for reconstruction of the sections

8. Recommend changes to

TxDOT Policies

• Based on the outcome of a ll tasks, recommend changes to the TxDOT 2004 Specifications

9. Submit Reports

• a technical memorandum at the end of each task• A final report documenting a ll work performed, method used, and results achieved.• A Project Summary Report (PSR)

Figure 4 – Overview of Research Approach


Exhibit B

Task 1. Information Search and Collection

A substantial review of literature has been carried out during the preparation of this proposal. We have already identified substantive work in this area throughout the Unites States and the world. The rehabilitation and reconstruction of the rural intersections has not been the focus of many studies in the US. TxDOT online pavement design guide provides information about the design of intersections with hot mix and concrete overlays. However, these solutions are mostly geared towards urban intersections. The Illinois DOT is one of the few state agencies that have instructions for designing and rehabilitating the rural intersections. Their specifications indicate

The type of pavement material selected for intersections will depend upon the existing pavement type and the volume and type of vehicles crossing or turning at the intersection. High-stress intersections are defined as those under stop control that have one or more of the following conditions:

The approach grade on any stop-controlled leg of the intersection is greater than 3.5%. The two-way ADT for trucks is greater than 400 vehicles in rural areas or 800 vehicles in

urban areas. The ADT for turning trucks on any one leg of the intersection is greater than 200 vehicles in

rural areas or 400 vehicles in urban areas.

Pavement types for high-stress intersections are limited to either of the following materials: PCC; or AC Superpave Ndesign ≥ 90. Use these materials a minimum of 150 ft back from the location of the stop bar. The maximum length normally will be the length of the turn lane plus the taper. If an existing intersection exhibits rutting and shoving of the bituminous concrete surface material, consider complete reconstruction rather than resurfacing the intersection.

Those intersections that are not considered high-stress but have an AC pavement type exhibiting distress (e.g., rutting, shoving) should be investigated to determine the cause. Examine and test the existing pavement structure to determine where any unstable material exists. If found, remove and replace the unstable material prior to resurfacing.”

A number of other states (e.g., Colorado, Oregon, Maryland and Kansas) provide some guidelines that are not much different than the Illinois DOT’s specifications.

By far the most comprehensive work in this area is carried out outside the United States. A few examples that we have identified include:

The Federation of Canadian Municipalities and Canadian National Research Council based on practical Canadian experience supplemented by technical information scan of Canada and US have developed a comprehensive document. In that document entitled “Rut Mitigation Techniques at Intersections9,” they outlined the best practice for the cost-effective, technically-sound mitigation of intersection rutting, and provided an intersection pavement rut mitigation action plan to ensure good performance of existing and new asphalt pavements.

In a report for the International Bank for Reconstruction and Development (IBRD) entitled “Low Cost Design Standards for Rural Roads Projects,” Evans (2005)10 developed a comprehensive guideline for the rehabilitation and construction of low-volume roads. The report provides comprehensive guideline for considering traffic volume, the geometry of the

9 http://www.sustainablecommunities.fcm.ca/files/Infraguide/Roads_and_Sidewalks/rut_mitigation_techn_intersections_.pdf 10,http://siteresources.worldbank.org/introadshighways/Resources/DesignManualforLowCostRuralRoadsinRomania-finaldr.pdf


http://siteresources.worldbank.org/introadshighways/Resources/DesignManualforLowCostRuralRoadsinRomania-finaldr.pdf

http://siteresources.worldbank.org/introadshighways/Resources/DesignManualforLowCostRuralRoadsinRomania-finaldr.pdf


Exhibit B

road and the pavement section in providing cost effective solutions for low-maintenance rural roads.

The Association of State, Territory and Federal Road and Traffic Authorities in Australia (Austroads, 2004)11 has published a comprehensive document for design of rural roads both thinly surfaced and unsurfaced. The New Zealand Transit12 that follows the Austroads (2004) developed a supplement to that document with special provisions for the structural design of intersections.

The Southern African Development Community (SADC)13 has released a report that is designed to provide a synthesis of practical, state-of-the-art approaches to provision of low-volume sealed roads. The report is based largely on regional knowledge and experience, while taking into account international best practice.

Further search for nationwide and international electronic information will be carried out to ensure that all relevant materials have been collected. The focus of this search will be toward the methods and protocols for identifying the causes of excessive permanent deformation and technically-sound, cost-effective solutions to that problem.

The results from the search will be summarized in a concise manner and will be reported to the PMC of the project. Aside from the documentation of practices for mitigating rutting at intersections worldwide, a matrix of solutions will be provided that enumerates at a minimum the following items:

Under what traffic volume, environmental condition, pavement structure the solution is effective?

Which alternative is appropriate for maintenance, rehabilitation or reconstruction? What are the advantages and disadvantages of each solution? What is the cost-benefit of the solution? How adaptable the solution is to TxDOT operation?

Task 2. Understanding and Documenting Extent of Problem and Solutions in Texas

This task consists of several subtasks so that the extent and the nature of excessive permanent deformation at the intersections in Texas can be documented.

Task 2a. Surveying TxDOT Districts: With the help from the PMC, we will develop a questionnaire and distribute it to all districts. The questionnaire, which will be concise to minimize the demand on the time of the TxDOT staff, will serve the following purpose:

To document the extent of the excessive permanent deformation at their intersections, To locate the districts that perceive that they can benefit from the outcome of this study, To identify the current solutions typically used to remedy this problem, To document the perceived performance of their intersections after remediation, and To solicit projects that can be incorporated in this study.

The outcome of the questionnaire will be summarized, and will be followed by face-to-face or telephone information to obtain more detailed information.11 http://www.austroads.com.au/pavement/index.html 12 http://www.transit.govt.nz/content_files/technical/ManualSection147_FileName.pdf 13 http://www.transport-links.org/sadc/en/Chapter5.pdf


http://www.transport-links.org/sadc/en/Chapter5.pdf

http://www.transit.govt.nz/content_files/technical/ManualSection147_FileName.pdf

http://www.austroads.com.au/pavement/index.html

Exhibit B

Task 2b. Documenting Forensic Studies Related to Intersections: CST as well UTEP and other institutions have been involved in a number of forensic studies related to this problem. UTEP was involved in the past in developing a database of forensic studies in the State for CST. We will accumulate all relevant forensic studies and summarize them in a concise manner. As part of this task, we will also visit with the staff of CST (e.g., Dar Hao Chen, Joe Leidy and Mark McDaniel) and our colleagues from TTI and CTR (e.g., Tom Scullion) that are most involved in forensic. We will interview them to ensure that we have accumulated all forensic studies.

Task 2c. Visit with Districts: Based on the results of Tasks 2a and 2b, about a dozen districts will be selected for site visit. The criteria for selection of the districts will include the extent that they face the excess permanent deformation at their intersections, their climatic condition (e.g., east Texas vs. west Texas), their type of subgrade (e.g., clayey vs. sandy) and the level of traffic (e.g., urban districts vs. rural districts).

In these site visits, we will meet with the Directors of Construction, Design and Maintenance to comprehensively document their typical problems and their effective and ineffective remedies to solve their problems. We will also share the matrices of the remedies accumulated in Task 1 to get their impression about the feasibility of implementing them in their district.

We will also locate candidate locations where the problems more frequently occur for site visit. We will try to gather as much historical data about the recommended locations (in terms of construction and maintenance records and as built pavement structure, the typical truck traffic and best estimate of the ADT) either from the district office or the relevant area offices. We will then visit candidate locations to document the extent of the damage and/or the effectiveness of the remedies. If feasible, we will request that the maintenance supervisor of the area office to accompany us so that we can obtain their perspective about the locations. If feasible, we will also perform some rudimentary site evaluation by performing simple tests (e.g., DCP) to obtain some indication of the structure integrity of the section. Other information, such as the speed limits, the location of the stop signs, the slopes at the intersections, the geometry of the intersections, the drainage conditions, will also be documented.

This information will be placed in a database for further trend analysis to determine the common attributes that may contribute to the excessive permanent deformation of the site. Also, the information obtained from the Directors of Construction, Design and Maintenance, the staff of CST, and other TxDOT personnel will be quite valuable in the design of the expert system.

At this time, we will also present a prototype guideline that will serve in initiating Tasks 4 through 7 below. This guideline will be continuously and iteratively improved during Tasks 4 through 7.

The results from this task will be summarized and shared with the PMC and the staff of CST for their review and comment.


Exhibit B

Task 3. Selection of Candidate Sites for in-depth Evaluation

With the consensus of the PMC, about 12 sites will be selected to cover the different regions and types of damage observed in Texas. Effort will be made at the beginning of the project to contact progressive Districts and coordinate selection of upcoming construction sites. Also, the information gathered in Tasks 1 and 2 will provide a good guideline for selecting these sites. With the help of the PMC, and the analysis of the results from Task 2, we will ensure that the inference space of types of excess deformations and the diverse geographical conditions of the State is covered with these sites. A partial list of criteria to be considered in selecting the sites will include:

o The type of distress observed (instability rutting vs. structural rutting)o The type of subgrade (clayey vs. sandy)o The pavement structure (e.g., with two-course surface treatment vs. with HMA)o Traffic volume (rural vs. urban)o Environmental condition (east Texas having more rainfall vs. west Texas considered

more arid)

Preference will be given to the sites that are scheduled for maintenance, rehabilitation or reconstruction. This will allow us to work with districts to propose an action plan for their consideration.

The results from this task will be summarized in a concise manner and will be reported to the PMC of the project. At this juncture of the project, we propose a half-day meeting with the PMC, representatives of CST, Maintenance Division and other TxDOT personnel knowledgeable in this area. In the meeting, we will present the information from Tasks 1 through 3 and seek feedback from the group. At that meeting, the locations of the sites for comprehensive evaluation will also be suggested for the concurrence of the group.

Task 4. Thorough Forensic Study of Candidate Sites

An extensive field evaluation consisting of the field testing, sampling of the materials and laboratory testing will be carried out at each site selected in Task 3. The prototype guideline developed in Task 2 will be initially used in this task. Approximately two-thirds of the sites will be used to develop the preliminary protocols, specifications and guidelines (as discussed in Tasks 5) and one-third for refining them as discussed in Task 7). Some of the activities to be recommended in the prototype guideline are discussed in Task 2c and some other ones are discussed below. It should be emphasized that the activities described below are more than needed for the final guideline. The extra activities are however necessary for fully understanding the process of intersection rutting and assessing the effectiveness of the process.

Field Testing: The main reason for the field testing is to document the layer(s) that have experienced excessive rutting, to isolate the layer(s) that contributed to the rutting, to obtain field data for evaluating the structural capacity of the pavement, and to obtain materials for subsequent lab testing. Typical field testing, in addition to the information about the site as collected in Task 2c, may include the following steps.

1. Perform Condition Survey to document the surface rutting and cracking at the site


Exhibit B

2. Perform FWD and GPR tests in the wheel path and the centerline of the section to estimate the modulus and thickness of the layers at and near intersection.

3. Excavate a 3 ft by 12 ft trench by removing the pavement layers one at a time down to 2 ft in subgrade.

4. Measure the density and moisture content of each layer with a Nuclear Density Gauge. 5. Conduct DCP tests directly on top of the subgrade and base material.6. Collect HMA (if applicable), base and subgrade materials for lab testing. 7. Smooth one wall of the trench, nail string lines to the smoothed wall of the trench and

measure the layer thicknesses at 6 in. intervals to measure the rutting of the HMA (if applicable), base and subgrade, individually.

8. Refill the trench.

Lab Testing: The primary reason for lab tests is to develop a preliminary database for typical design parameters needed for FPS19 and VESYS. After the completion of the field work, the materials and cores will be brought to UTEP labs for further tests. These tests are summarized in Table 2.

Table 2 – Laboratory Activities on Materials Retrieved from SiteStep Test Outcome

Hot

Mix

Asp

halt

(if a

vaila

ble)

NCAT Ignition Binder content and gradation of mix along projectGradation

Extraction of binder Binder PropertyViscosity of binderGmm Determine air void contents of specimensGmb

Hamburg Wheel Tracking Device on cores* Estimate performance of mixIDT strength of coresComplex Modulus and Permanent

Deformation on lab specimens prepared at field air voids*

Estimate parameters for structural analysis

Bas

e an

d Su

bgra

de

Gradation and Atterberg Limits Classify the material, assess the moisture condition of the materialMoisture Density Curve

Texas Triaxial Tests Estimate Strength and ClassResilient Modulus/Permanent Deformation

Tests at Optimum Moisture Content Estimate parameters for structural analysisResilient Modulus/Permanent Deformation Tests at In-place Moisture Content

Moisture Susceptibility To assess impact of moisture* These tests will be carried out if the thickness of the HMA layer is greater than 2.5 in.

Structural Analysis: Based on the results of the field and lab tests and the representative traffic volume and ADT, a comprehensive structural analysis of the section will be carried out using FPS19, VESYS and PCASE (a free software package by Army Corps of Engineers as described in the background section) to verify that the field observations and the output of these software packages are comparable. If necessary, the output of the programs will be calibrated with the field data available.

Recommendation of Alternative Remediation Strategies: Based on the outcome of the field observations, laboratory testing, and structural analysis, one or more rehabilitation strategies will


Exhibit B

be proposed along with a life-cycle cost analysis of each method. The finding will then be shared with the personnel of the district for their input. In cooperation with the district, the best alternative selection will be selected.

Construction and Monitoring of Sections: Through change order or RTI funds (if needed) and with the assistance of the districts, the remediation alternatives will be implemented. If the district chooses to apply the recommended remediation(s), the construction process will be documented by UTEP team through videotaping and interview of the personnel involved. If the district is open to the suggestion of placing several of the alternatives in the same or close-by intersections, we will be pleased to monitor all of them. During the construction we will perform additional quality control of the construction. Upon completion of the project, FWD tests will be carried out to document the structural improvements to the site. This monitoring will be carried out quarterly until the project is completed.

Overall Assessment: The results from each of the steps mentioned above will be placed in a database for further analysis. Upon completion of each project, the lessons learned and the trends observed will also be added to the database.

The results from this task will be summarized in a concise manner and will be reported to the PMC of the project.

Task 5. Develop Preliminary Guideline

Upon completion of about two-thirds of the candidate projects, we will evaluate the prototype guideline. Based on the experience gained, we will eliminate activities that are of marginal benefit, we will remedy inconsistent steps and we will ensure that the process in the guideline can be implemented smoothly. To develop the preliminary guideline, we will carefully consider the existing TxDOT specifications. At a minimum, the guideline will contain the following:

1. What are typical distressed pavement sections found in Texas

a. Description of each distress type (with representative photos)b. What are the most probable causes of each type of distressc. Which layer(s) of pavement structure are most probably contributing to distress

2. What are typical remediation strategies (Maintenance, Rehabilitation, Reconstruction)

a. Description of each remediation process (with step-by-step process)b. Probable feasibility of each remediation strategy to solve each type of distress

identified in Item 1c. A matrix of effectiveness vs. cost for each feasible solution including cost-benefit

ratio considering traffic volume and budgetary constraints:i. Effectiveness: short-term (a band aid), intermediate (1 to 3 years), long term

(3 to 7 years)ii. Cost: inexpensive (less than $5/yd2) , moderately expensive (less than

$15/yd2), expensive (more than $15/yd2)iii. Cost-benefit ratio by color coding the matrix (green: good use of funds,

yellow: marginally beneficial, red: waste of funds)

3. What preliminary information should be gathered for determining the best remediation strategies?


Exhibit B

a. The type and volume of traffic (how to get them)b. The location of stop signsc. The depth, extent and shape of the rutted section (how to measure them)d. The speed limit of the roads leading to the intersectione. The best estimate of the pavement layers’ thickness and type (how to get them)

4. What additional information needed for properly designing and constructing each remediation strategy?

a. When to perform coring and sampling (with step-by-step process)b. When to perform nondestructive testing with FWD and/or GPR (with step-by-step

process)c. When and what laboratory tests are necessary (with step-by-step process)d. When and what software to use to design the new intersection (with step-by-step

process)e. When and how to perform life-cycle cost analysis (with step-by-step process)

5. How to select the best remediation strategy (with step-by-step process) from information obtained in Items 2 through 4 given the practices of the district and budget constraints

6. How to go about material selection for each remediation and layera. How to go about selecting the appropriate hot mix asphalt (with step-by-step process)b. How to go about selecting the type of base and/or how to treat (use less than 2%

additive) or stabilize (more than 2% additive) if necessaryi. When to use base without treatment of stabilization (with step-by-step

process)ii. When and how to decide on treatment or stabilization

1. What type of additive to use for a given base (with step-by-step process)

2. How to decide on additive concentration ((with step-by-step process)c. When and how to improve subgrade

i. When to use subgrade without treatment of stabilization (with step-by-step process)

ii. When and how to decide on treatment or stabilization1. What type of additive to use for a given subgrade (with step-by-step

process)2. How to decide on additive concentration (with step-by-step process)

7. What are the best construction practices for each remediation methoda. Site preparation (with step-by-step process)b. Construction practices (with step-by-step process)

8. What type of quality control to implement for each remediation method (with step-by-step process)

The guideline will be shared with the PMC of the project for their review and comment.


Exhibit B

Task 6. Develop Final Guideline

Based on the information gathered in Task 5, results of the last one-thirds of the field projects and feedback from the PMC of the project, the preliminary guideline will be modified and provided to TxDOT for limited implementation.

At this time, this information will be incorporated in a concise but attractive document that can be used as a guidebook by TxDOT personnel. An electronic version of the guide will also be provided with appropriate hyperlinks to definitions, relevant TxDOT specifications, step-by-step procedures and other web-pages that provide additional information to TxDOT personnel.

Task 7. Develop an Expert System

The implementation of an expert system for the selection of appropriate remedies for intersections seems logical. As briefly discussed in Task 5, the decision tree for arriving to the most appropriate decision can be rather complex. An expert system is a knowledge-based system whose performance is intended to rival that of human experts while being highly domain specific. It can be used to record and distribute scarce expert knowledge, to apply the expert knowledge to remote locations, to ensure the quality of problem solving, and to train experts out of ordinary people.

The expert system in this case will serve as a step-by-step guidance on the process of designing the optimum solution. Traditionally a guideline with look up tables are used to develop or carryout the decision making. However, utilizing the expert system will facilitate the process and will provide a means for future modification and explanation of the knowledge base. The modularity of the database structure in an expert system allows for including additional options that are proven successful with time. This also applies to incorporating knowledge of pavement engineers as it becomes available. The expertise of the engineers that are experienced with intersection remediation would be utilized by everyone. In addition to its modularity with its interaction with databases, an expert system shell has the ability to call outside executable programs and communicate with database. Therefore, it’s flexible to incorporate mathematical and analytical models, and mechanistic-empirical relationships. The expert system will ensure a more rational, faster and consistent manner of selecting an alternative. Also uniformity of the decision process in using an expert system promotes more design consistency across the districts.

The expert system will have a knowledge base that will include all the factors that will be developed in the guidelines to reach the final decision. Intermediate and final conclusions will be available with comments, explaining how those conclusions where reached. The system’s knowledge base will be developed by incorporating the expertise in terms of IF-THEN rules that will contain the reasoning of the results and guideline from the scenarios and results of Tasks 1 through 6. The expert system will also include design factors from expertise and other relevant documentation specific to intersections. The results from the interviews and Tasks 3 through 6 will be analyzed and translated into IF-THEN statements. The knowledge translated into IF-THEN statements will contain all the factors considered in the design guideline, such as: (a) soil characteristics; (b) weather; (c) highway classification; (d) historical construction methods; (e) materials; (f) traffic and (g) cost factors.

Under Project 0-5430, UTEP researchers have developed an expert system for guiding TxDOT in considering strategies for mitigating the premature failure of low-volume roads on high PI


Exhibit B

clays. The knowledge and expertise gained in that project can readily be translated to this project since the developer of that software is part of this team.

Task 8. Recommend Changes to TxDOT Policies

Based on the results from Tasks 1 through 7, several recommendations in terms of changing the design procedures, test procedures, and construction practice will be made for inclusion in TxDOT 2004 Standard Specifications.

Task 9. Submit Reports

After the completion of each task, a technical memorandum will be submitted to the PMC of the project with a copy to RTI.

At the end of the project, a report will be submitted that documents completely the work performed, methods used, and results achieved the achievements in Tasks 1 through 8.

A project summary report will also be delivered at that time.

Identification of Information Technology (IT) Deliverables to TxDOT

Summary of the development to be performed: A small software package may be developed. No hardware will be developed.

Itemized list of IT deliverables proposed for ultimate transfer to TxDOT: The IT deliverables may be a small program.

Estimated cost associated with IT deliverables for ultimate transfer to TxDOT: negligible Proposed use of IT deliverables within TxDOT: The software can be used to determine the

design values to be manually input to current design guides Impact of IT deliverables to TxDOT IT infrastructure and support personnel: The impact

should be negligible. The design guide will most probably be developed in Visual C++ or as an Excel sheet. The executable can be installed using standard Windows Installation program. .

Description of proprietary IT deliverables: No proprietary software will be delivered. Implementation strategy for how the IT deliverables will be accepted and deployed: As

indicated above, the deliverables, which will be delivered on a CD, can be readily installed using Windows installation software.

Estimated net monetary benefit to be gained by TxDOT through use of IT deliverables: The deliverables can potentially save millions dollars in terms of lower maintenance.


Exhibit B

Assistance or Involvement by TXDOT

Interaction between UTEP and TxDOT is required to ensure that the protocols and procedures developed are consistent with TxDOT directions.

Assistance in field testing in terms of providing equipment, traffic control and coring is also anticipated. TxDOT will coordinate the necessary traffic control and provide nondestructive testing devices.


Exhibit B

Deliverables Table

RTIDeliverables TableProject No. 0-5566

Form DelTblEx(Rev. 12/2006)

(GSD-EPC)

Note: Deliverables on this Table are not considered received by TxDOT until submitted to RTI.See chapter 8 of the Research and Implementation Manual for standards for all deliverables.

Products: Minimum Stand-alone Products will be as specified on the Project Statement (Research Project) or IPR (Implementation Project). Examples of products typically most appropriate as stand-alone items include Guidebooks, Training Materials, Devices, Instruction Manuals, Brochures, and Software.

No. Stand-AloneProduct Description

Due Date (normally due

at or before project

termination)

ResponsibleParty for Joint

Project(if blank, RS is

assumed)

Comments

P1 A handbook designed for maintenance personnel showing “best practices” for maintaining flexible pavements at intersections.

8/31/10 RS

P2 Expert System Downloaded off the UTEP training website for TxDOT.

Reports: Minimum Reports will be as specified on the Project Statement (Research Project) or IPR (Implementation Project).

No.Report Description(Succinctly describe

intended contents of each report.)

Due Date(if blank,

defaults to 60 days after

project termination)

ResponsibleParty for Joint

Project(if blank, RS is

assumed)

Comments

R1 Comprehensive and detailed documentation of all work tasks and results.

10/31/10 RS Report that recommends improved construction methods, materials and maintenance of flexible pavements at intersections. An appendix will include modified specifications for flexible pavement design at urban and rural intersections.

PSR Summary of work performed, findings and conclusions

10/31/10 RS

Date Updated:


Exhibit B

Schedule of Research Activities


RTIResearch Facilities and Personnel Data Sheet

Form Personnl(5/2004)

(GSD-EPC)

Project No: 0-5566 Date: May 20, 2008

Research Agency: The University of Texas at El Paso

1. Research Supervisor’s Experience

Dr. Nazarian will lead this project. As reflected in his resume in the appendix, Dr. Nazarian has led or has been involved in several national and TxDOT projects dealing with design, construction and material characterization in situ and in the laboratory and instrumentation. The examples of these projects are TxDOT Projects 0-5430, 0-4188, 0-5562, 0-5569, 0-5797, and 9-4320. Dr. Nazarian has about twenty years of experience in design and characterization of pavements.

2. Research Staff ExperienceImad Abdallah, MSCE is the Associate Director of the Center for Transportation Research Systems. He has thirteen years of work experience and has been instrumental in research efforts on several projects dealing with data modeling and data analysis. He has led the efforts in developing pavement performance models using tools such as Artificial Neural Networks (TxDOT Project 0-1711 – Development of a Comprehensive, Rational Method for Determination of Remaining Life of an Existing Pavement), and other nonlinear and statistical based algorithms (TxDOT Project 0-1780 which involved development of tool to estimate design modulus from seismic data). He was also involved with developing an Expert System (TxDOT Project 0-5430 for realistic design guidelines for low classification roads in high PI clays. For a list of relevant working experience please see attached vitae.

Dr. Deren Yuan has extensive theoretical background and hands-on experience in non-destructive testing and field evaluation. He has been involved in a large number of research projects and forensic studies of TxDOT in the last 15 years. For a list of relevant working experience please see attached vitae. He will assist the team in the collection and analysis of field studies.

Mr. Jose Garibay is the Laboratory Manager of UTEP’s CTIS laboratories. He obtained his BS in Civil Engineering from UTEP in 2005. He is experienced in TxDOT laboratory testing procedures since he worked on several TxDOT projects that required a large amount of laboratory testing. His hands-on experience will allow a smooth and practical coordination of the field operations and laboratory testing.

3. Research Facilities

The Center for Transportation Infrastructure Systems (CTIS) at UTEP is internationally known as a center of excellence in nondestructive testing of transportation infrastructure. The annual operating budget of the Center is over $1.5 million. As such, it is well-staffed to carry out the technical duties of this project. CTIS has extensive field and lab facilities that will be used for the execution of this project.

Project 0-5566 Page 1 of 10

Nondestructive Testing CapabilitiesA large number of nondestructive testing devices are available at CTIS. These include:

Seismic Pavement Analyzer Potable Seismic Pavement Analyzer GSSI air-launched and ground-coupled GPR units with antennae ranging from 400 MHz

to 2.1 GHz. Portable semi-automatic Impulse Response method.

The group has extensive experience with other NDT devices such as:

Falling Weight Deflectometer Lightweight Deflectometer Geogauge.

The staff of CTIS have developed and use a CTIS in a partnership with the Department of Geological Sciences operates the Laboratory for Environmental and Engineering Geophysics (LEEG) at UTEP. LEEG is an $800,000 facility funded by the Department of Defense and operates virtually any geophysical methods applied in the field of engineering, from elector-magnetic methods, to several electrical methods, to most seismic methods.

A number of well-qualified electric, electronic, mechanical technicians and a large machine shop with very experience machinists are at the disposal of the researchers. CTIS is also staffed with an Electronic Engineer with extensive background in field instrumentation and automatic data acquisition.

Over the years, CTIS has accumulated a large number of digital recording devices, signal analyzer and a vast variety of sensors. If need be, any test method can be configured and performed manually in a short period of time.

Material TestingCTIS is equipped with the state-of-the-art apparatus for conventional and advance testing of pavement materials. Most of the laboratory apparatus have been replaced or acquired in the last ten years. In September 2007, CTIS laboratory relocated to a new facility with equipped with another $0.5 million of advanced testing capabilities.

Asphalt Binder and Mix Testing

In the asphalt lab, all traditional and SHRP binder testing equipment is available. An MTS system placed in a walk-in temperature control room can be used for strength and modulus tests of hot mix, including all simple-performance tests and diameteral resilient modulus. An IPC beam fatigue test device is also available. Several sonic and ultrasonic lab devices for NDT of hot mix specimens are also available. We have also developed a direct shear test device explicitly for measuring bond strength at the interface of two pavement layers.

Concrete Testing

The concrete laboratory is equipped with all computer-controlled devices to conduct traditional strength tests (compressive, flexural and indirect tensile), static and dynamic modulus, and coefficient of thermal expansion, amongst others. Several seismic and ultrasonic NDT devices for lab testing are also available.

Small-Scale Testing


Another capability of our labs is to prepare and test small-scale pavement section under cyclic and static loads. Specimens up to 4 ft can be constructed, instrumented and tested under controlled temperature and moisture conditions.

Soils and Aggregate Testing

The soil and aggregate lab is equipped with all traditional equipment for characterizing the aggregates and index tests. One MTS system is dedicated to conducting resilient modulus and permanent deformation tests as per AASHTO T-307 on bases and subgrades. In addition, two computer-controlled systems for conducting strength tests such as triaxial and unconfined compressive strengths, a computer-controlled direct shear tests and two computer-controlled devices for consolidation tests are available. Advanced nondestructive testing devices such as bender elements and resonant column for modulus, dielectric constant probes for moisture susceptibility are available.

4. Scheduling

Other planned commitments of the principal research team members during the proposed study period are as follows:

Responsibility Soheil Nazarian Imad Abdallah Deren Yuan Jose GaribayTxDOT Research 15% 35% 25% 30%Other Research 25% 25% 20% 20%

Teaching 25% -- -- --Other 15% -- -- --TBD 20% 40% 55% 50%Total 100% 100% 100% 100%

Performance

The Research Supervisor is well known to TxDOT engineers for his solid performance as a researcher and administrator from completed TxDOT studies. They have been active in the TxDOT research program for over a decade and are recognized for their expertise in the areas of instrumentation, materials testing and performance modeling. Please see attached biographical information for more detail.

Texas Department of Transportation maintains the information collected through this form. With few exceptions, you are entitled on request to be informed about the information that we collect about you. Under §§552.021 and 552.023 of the Texas Government Code, you also are entitled to receive and review the information. Under §559.004 of the Government Code, you are also entitled to have us correct information about you that is incorrect. For inquiries call 512/465-7403.


APPENDIX A

BIOGRAPHICAL INFORMATION


Soheil Nazarian, Ph.D., P.E.Education:

Ph.D. in Civil Engineering, University of Texas at Austin, 1984 M.S. in Civil Engineering, Tufts University, 1981 M.S. in Civil Engineering, University of Tehran, 1979

Experience:Academic: Professor, Univ. of Texas at El Paso, Sept. 1997- present

Director of Center for Transportation Infrastructure Systems, 1997 - present Associate Professor, Univ. of Texas at El Paso, Sept. 1992-Aug. 1997 Assistant Professor, Univ. of Texas at El Paso, Sept. 1988-Aug. 1992 Research Engineer, Univ. of Texas at Austin, Jan. 1985-Aug. 1988

Research Grants and Contracts:

PI and Co-PI of more than 60 projects primarily dealing with material characterization and laboratory and field methods. Examples include:

“Realistic Design Guidelines for Low Classification Roads in High PI Clays,” Jan. 06 – Jan. 09, TxDOT and FHWA, $312,000 (with Puppala, UTA).

“The Effects of Pulverization on Flexible Pavement Design Procedures,” Sept. 06 – Aug. 08, TxDOT and FHWA, $229,000 (with Yuan).

“Role of Coarse Aggregate Point and Mass Strength on Resistance to Load in HMA,” Sept. 06 – Aug. 08, TxDOT and FHWA, $273,000 (with Masad TTI).

“Verification of the Modified Triaxial Design Procedure,” Sept 02 - Aug. 05, TxDOT and FHWA, $210,000 (with Fernando and Tandon).

“Materials, Specifications, and Construction Techniques for High Performance Flexible Bases” Sept 01- Aug. 05, TxDOT and FHWA, $245,000 (with Scullion and Yuan).

“Impacts of Construction Quality on Life Cycle Performance of Pavements Using Mechanistic Analysis,” Sept 00 - Aug. 05, TxDOT and FHWA, $367,000 (with Ferregut, Abdallah and Yuan).

“Design Modulus Values Using Seismic Data Collection,” Sept. 1997 - Aug. 2001, TxDOT and FHWA, $241,000 (with Yuan).

"Development of Structural Field Testing of Flexible Pavement Layers," Sept. 96 - Aug. 03, TxDOT and FHWA, $438,000 (with Yuan and Tandon).

"Development of a Comprehensive, Rational Method for Determination of Remaining Life of Existing Pavements," Sept. 96 - Aug. 00, TxDOT and FHWA, $251,000 (with Ferregut and Melchor).

Publications

Author and co-author of more than 100 papers and reports mostly in use of geophysical engineering in infrastructure testing, evaluation and management. Examples include:

1. “An Integration Algorithm for Evaluation of Pavement Systems,” (with Abdallah and Ganji), Geotechnical Special Publication, ASCE, Reston, VA, 2006.

2. “Laboratory Evaluation of Stiffness Properties of Stabilized Bases,” (with Carrasco and Carrasco), Geotechnical Special Publication, ASCE, Reston, VA, 2006.


3. “Nondestructive Quality Control of Geo-materials Using Seismic Methods,” (with Celaya and Yuan), Geotechnical Special Publication, ASCE, Reston, VA, 2006.

4. “Rapid-Reduction to Interpretation of SASW Results Using Neural Networks,” (with Abdallah and Yuan) Journal of Transportation Research Board No. 1868, Washington, DC, pp. 150-155, DC, 2004.

5. “Using Seismic Data in Structural Design of Flexible Pavements,” (with Abdallah and Yuan) Geotechnical Special Publication No. 126, pp. 967-976, ASCE, Reston, VA, 2004.

6. “Optimizing Opening of PCC Pavements Using Integrated Maturity and Nondestructive Tests,” (with Yuan and Medichetti) Journal of Transportation Research Board No. 1861, pp. 3-9, Washington, DC, 2003.

7. “Feasibility of Backcalculation of Nonlinear Parameters of Flexible Pavement Layers from Nondestructive Testing,” (with Abdallah, Meshkani and Ke) Journal of Transportation Research Board No. 1860, pp. 16-25, Washington, DC, 2003.

8. “Quality Management of Flexible Pavement Layers with Seismic Methods,” (with Arellano and Yuan), International Conference on Highway Pavement Data, Analysis and Mechanistic Design Applications, Vol. 2, pp. 69-81, Columbus, OH, 2003.

9. “Feasibility of Backcalculation of Nonlinear Parameters of Flexible Pavement Layers from Nondestructive Testing,” (with Meshkani and Abdallah), International Conference on Highway Pavement Data, Analysis and Mechanistic Design Applications, Vol. 2, pp. 135-81146, Columbus, OH, 2003.

10. Determining Design Modulus Values with Seismic Data,” (with Abdallah and Yuan), International Conference on Highway Pavement Data, Analysis and Mechanistic Design Applications, Vol. 2, pp. 177-188, Columbus, OH, 2003.

11. “A Simple Method for Determining Modulus of Base and Subgrade Materials,” (with Yuan and Williams) ASTM STP 1437, pp. 152-164, ASTM, West Conshohocken, PA, 2003.

12. “Use of Resilient Modulus Test Results in Flexible Pavement Design,” (with Abdallah, Meshkani and Ke), ASTM STP 1437, pp. 3-15, ASTM, West Conshohocken, PA, 2003.

13. ”Forensic Study of Warranty Project on US 82,” (with Chen, Scullion and Bilyeu), Journal of Performance of Constructed Facilities, ASCE, New York, NY, 2002.

14. “Quality Management of Base and Subgrade Materials with Seismic Methods,” (with Yuan and Arellano), Journal of Transportation Research Board No. 1786, pp. 3-10, Washington, DC, 2002.

15. “A Probabilistic Method for Estimating Pavement Performance Using Falling Weight Deflectometer,” (with Abdallah, Melchor and Ferregut), 6th International Conference on Bearing Capacity of Roads, Railways and Airfields, Lisbon, Portugal, 2002.


Imad Abdallah, MSCE

EducationM.S. in Civil Engineering, The University of Texas El Paso, 1996B.S. in Civil Engineering, The University of Texas El Paso, 1994

Experience2003 - present Associate Director, Center for Transportation Infrastructure Systems, UTEP1999 - 1997 Researcher, UTEP1994 – 1996 Teachers Assistant, UTEP

Research Grants and Contracts: PI, Co-PI, and Researcher on: “Implementation of a Web-based training site for software at UTEP,” April 04 – Aug. 05,

TxDOT, $50,000 (with Nazarian). “Integration of Non-Destructive Testing Data Analysis Techniques,” Sept. 02 – Aug. 04,

TxDOT and FHWA, $265,790 (with Nazarian, Ferregut and Yuan). “Impacts of Construction Quality on Life Cycle Performance of Pavements Using

Mechanistic Analysis,” Sept 00 - Aug. 05, TxDOT and FHWA, $367,000 (with Ferregut, Abdallah and Yuan).

“Design Modulus Values Using Seismic Data Collection,” Sept. 1997 - Aug. 2001, TxDOT and FHWA, $241,000 (with Nazarian and Yuan ).

"Development of a Comprehensive, Rational Method for Determination of Remaining Life of Existing Pavements," Sept. 96 - Aug. 00, TxDOT and FHWA, $251,000 (with Nazarian, Ferregut and Melchor).

PublicationsRecent Papers:

1. “Rapid-Reduction to Interpretation of SASW Results Using Neural Networks,” (with Abdallah and Yuan) Journal of Transportation Research Board No. 1868, Washington, DC, pp. 150-155, DC, 2004.

2. “Feasibility of Backcalculation of Nonlinear Parameters of Flexible Pavement Layers from Nondestructive Testing,” (with Nazarian, and Meshkani), Journal of Transportation Research Board, Washington, DC, 2003.

3. “Use of Resilient Modulus Test Results in Flexible Pavement Design,” (with Nazarian, Meshkani and Ke), ASTM STP 1437, ASTM, West Conshohocken, PA, 2003.

4. “A Rapid Approach to Interpretation of SASW Results,” (with Wu, Wang and Yuan), 6th International Conference on Bearing Capacity of Roads, Railways and Airfields, Lisbon, Portugal, 2002.

5. “A Probabilistic Method for Estimating Pavement Performance Using Falling Weight Deflectometer,” (with Nazarian, Melchor and Ferregut), 6th International Conference on Bearing Capacity of Roads, Railways and Airfields, Lisbon, Portugal, 2002.

6. Integrating Seismic and Deflection Methods to Estimate Pavement Moduli,” (with Nazarian and Yuan), Journal of Transportation Research Board No. 1755, Washington, DC, pp. 43-50, 2001.

7. “Backcalculation of Pavement Profiles from SASW Test Using Artificial Neural Networks,” (with Gucunski and Nazarian), ASCE Special Publication 98, New York, NY, pp. 31-50, 2000.


8. “Estimation of Remaining Life of Flexible Pavement Systems Using Artificial Neural Networks,” (with Ferregut, Nazarian and Melchor), Proceedings Artificial Intelligence and Mathematical Methods in Pavement and Geomechanical Systems, Newark, Delaware, pp. 121-132, 2000.

9. “Calibration and Validation of Remaining Life Models Using Texas Mobile Load Simulator,” (with Melchor, Nazarian and Ferregut), Proceedings International Conference on Accelerated Pavement Testing, Reno, NV, 2000.

10. “Prediction of Remaining Life of Flexible Pavements with Artificial Neural Networks,” (with Nazarian, Ferregut and Melchor) STP 1375, ASTM, West Conshohocken, PA, pp. 484-498, 2000.

Recent Reports:1. “Optimizing Construction Quality Management of Pavements Using Mechanistic

Performance Analysis,” (with Hao, Nazarian and Ferregut), Research Report 4046-1, Center for Highway Materials Research, UTEP, November 2002 (submitted to TxDOT)

2. “Validation of Software Developed for Determining Design Modulus from Seismic Testing,” (with Nazarian and Yuan) Research Report 1780-5F, Center for Highway Materials Research, UTEP, November 2002 (submitted to TxDOT).

3. “Design Modulus Values Using Seismic Moduli SMART (Users Manual),” (with Meshkani, Yuan, and Nazarian), Research Report 1780-4, Center for Highway Materials Research, UTEP, November 2002 (submitted to TxDOT).

4. “Determination of Nonlinear Parameters of Flexible Pavement Layers from Nondestructive Testing,” (with Meshkani and Nazarian), Research Report 1780-3, Center for Highway Materials Research, UTEP, July 2001 (submitted to TxDOT).

5. “Stiffness Properties of Composite Pavements Using Artificial Neural Network-Based Methodologies,” (with Nazarian, Ferregut and Melchor), Research Report 1711-3F, Center for Highway Materials Research, UTEP, January 2001 (submitted to TxDOT).

6. “Artificial Neural Network Models for Assessing Remaining Life of Flexible Pavements,” (with Nazarian, Ferregut and Melchor), Research Report 1711-2, Center for Highway Materials Research, UTEP, January 2000 (submitted to TxDOT).

7. “A Sensitivity Study of Parameters Involved in Design with Seismic Moduli,” (with Ke, Nazarian and Yuan), Research Report 1780-2 Center for Highway Materials Research, UTEP, January 2000 (submitted to TxDOT).


Deren Yuan, Ph.D.

Education:

Ph.D. in Geological Sciences, University of Texas at El Paso, 1992 M.S. in Geophysics, Graduate School, Chinese Academy of Sciences, 1983

Experience:Academic: Research Engineer, Center for Highway Materials Research, University of Texas

at El Paso, Sept. 1993 - present Assistant Researcher, Geophysics Institute, Chinese Academy of Sciences, Aug.

1979 - Dec. 1982

Research Grants and Contracts Relevant to This Study:

“Innovative Testing Standards for Acceptance Criteria for Concrete Pavement,” Oct. 03 – Feb. 05, Innovative Pavement Research Foundation (IPRF), $640,000 (with Nazarian).

“Determining Capacity of Military Pavements: A Portable Sonic-Ultrasonic Stress-Wave Device -Phase II,” Nov. 02 – Nov, 04, DOD, $81,500 (subcontracting to Geomedia Research & Development).

“Integration of Non-Destructive Testing Data Analysis Techniques,” Sept 02- Aug. 04, TxDOT and FHWA, $260,000 (with Nazarian, Ferregut, Abdallah and Scullion).

“Quality Management of ACP and Base Using Project 1735 Findings,” Sept 02- Aug. 04, TxDOT and FHWA, $90,000 (with Nazarian).

“Materials, Specifications, and Construction Techniques for High Performance Flexible Bases” Sept 01- Aug. 05, TxDOT and FHWA, $245,000 (with Nazarian and Scullion).

“Impacts of Construction Quality on Life Cycle Performance of Pavements Using Mechanistic Analysis,” Sept 00- Aug. 03, TxDOT and FHWA, $212,000 (with Nazarian, Ferregut and Abdallah).

“Determining Capacity of Military Pavements: A Portable Sonic-Ultrasonic Stress-Wave Device -Phase I,” Jan. 99 – Jun., 99, DOD, $16,000 (subcontracting to Geomedia Research & Development).

"Development of Structural Field Testing of Flexible Pavement Layers," Sept. 96-Aug. 02, TxDOT and FHWA, $520,000 (with Nazarian and Tandon).

“Design Modulus Values Using Seismic Data Collection,” Sept. 97-Aug. 02, TxDOT and FHWA, $311,000 (with Nazarian).

“Development of Methods and Materials to Accelerate Construction of PCC Pavements,” Sept 00- Aug. 02, TxDOT and FHWA, $142,000 (with Nazarian, Weissman, and Melchor).

“Predicting Hot Mix Asphalt Performance from Measured Properties,” Sept. 99-Aug. 01, TxDOT and FHWA, $70,000 (with Nazarian and Tandon).

“Flaw Detection in Concrete Walls of Chernobyl Nuclear Power Plant,” May 99-Dec. 99, Jet Propulsion Laboratory, $ 70,000 (with Nazarian).

"Mobile Load Simulator Research Management System,” Sept. 95-Aug. 99, TxDOT, $62,000 (with Center for Transportation Research and Texas Transportation Institute).


Publications

“Use of Stress Wave Technique to Monitor and Predit Concrete Stress Development of,” (with Nazarian and Zhang), Airfield Pavement: Challenges and New Technologies , Proceedings of the Specialty Conference, Edited by Moses Karakouzian, ASCE, 2004, pp. 409-423.

“Variation in Moduli of Base and Subgrade with Moisture,” (with Nazariani) Journal of Transportation Research Board, Washington, DC, 2003 (accepted for publication).

“Optimizing Opening of PCC Pavements Using Integrated Maturity and Nondestructive Tests,” (with Nazarin and Medichetti) Journal of Transportation Research Board, Washington, DC, 2003 (accepted for publication).

“A Simple Method for Determining Modulus of Base and Subgrade Materials,” (with Nazarian and Williams) ASTM STP 1437, ASTM, West Conshohocken, PA, 2003 (accepted for publication).

“Feasibility of Using Stress Wave Technique to Monitor and Predict Early-Age Strength Gain of Portland Cement Concrete,” (with Nazarian), 4th International Conference on Road and Airfield Technology, Kunming, China, 2002.

“Quality Management of Base and Subgrade Materials with Seismic Methods,” (with Nazarian and Arellano), Journal of Transportation Research Board No. 1786, pp. 3-10, Washington, DC, 2002.

“An Initiative Toward Mechanistic Construction Quality Control Using Seismic Methods,” (with Nazarian), 6th International Conference on Bearing Capacity of Roads, Railways and Airfields, Lisbon, Portugal, 2002.

"Quality Control of Compacted Layers with Field and Laboratory Seismic Testing Devices," (with Nazarian), STP 1384, ASTM, West Conshohocken, PA, pp. 311-324, PA, 2000.

“Use of Seismic Pavement Analyzer in Forensic Studies in Texas,” (with McDaniel, Chen and Nazarian), STP 1375, ASTM, West Conshohocken, PA, pp. 346-364, 2000.

“Structural Field Testing of Flexible Pavement Layers with Seismic Methods for Quality Control,” (with Nazarian and Tandon) Transportation Research Record 1654, pp. 50-60, Washington, DC, 1999.

“Relating Laboratory and Field Moduli of Texas Base Materials,” (with Nazarian, Rojas, Pezo, Abdallah and Scullion) Transportation Research Record 1639, Washington, DC, pp. 1-11, 1998.

“Use of Seismic Pavement Analyzer in Monitoring Degradation of Flexible Pavements Under Texas Mobile Load Simulator (A Case Study),” (with Nazarian, Chen and Hugo) Transportation Research Record 1615, Washington, DC, pp. 3-10, 1998.

"Use of Seismic Pavement Analyzer for NDT of Roads," (with Nazarian and Baker), Proceedings Nondestructive Testing in Civil Engineering, Liverpool, UK, 1997.

"Quality Control of Portland Cement Concrete with Wave Propagation," (with Nazarian and Baker) Transportation Research Record 1544, Washington, DC, pp. 91-98, 1996

"Automated Surface Wave Method: Inversion Technique,” (with Nazarian), Geotechnical Engineering Journal, Vol. 119, No. 7, pp. 1112-1126, ASCE, New York, NY, 1993


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