itz civilized - uah uah 2009 concrete canoe design report “itz civilized” “it’s what’s...

It’s what’s inside that counts.ITZ CIVILIZED

Team UAH 2009

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ASCE National Concrete Canoe Competition

Design Report

Team UAH 2009 Concrete Canoe Design Report “ITZ Civilized”

“It’s what’s inside that counts.” i Table of Contents and Executive Summary

Table of Contents

Table of Contents.............................................. i Executive Summary .......................................... i Analysis............................................................ 1 Development and Testing ................................ 2 Project Management and Construction............ 4 Innovation and Sustainability .......................... 7

Organization Chart........................................... 8 Project Schedule............................................... 9 Design Drawing with Bill of Materials.......... 10 Appendix A – References ............................. A1 Appendix B – Mixture Proportions................B1 Appendix C – Gradation Curve & Table........C1

Executive Summary

The University of Alabama in Huntsville (UAH) was established in 1961 as a research center specifically aimed to support the growing aerospace science and missile fields. Forty-eight years later, our campus is located across the street from the second-largest research park in the nation in which nearly every major U.S. aerospace corporation is represented. We have a current enrollment of 7,431 with 141 students enrolled in Civil and Environmental Engineering. A large percentage of Team UAH is drawn from other engineering disciplines, particularly aerospace.

Our unorthodox, multi-disciplinary approach to the Concrete Canoe Competition is what has allowed us to represent the highly competitive Southeast Conference 15 times at the national level and to win 5 national championships. But with the recent rule changes, we had to demonstrate a strong understanding of the fundamentals of Civil Engineering. To reflect this, the theme we have selected for the year is ITZ Civilized.

The interfacial transition zone (ITZ) is the region of the cement paste around the aggregate particles. It is the weakest link in a normal concrete matrix and interactions there affect macroscopic properties, such as strength, permeability, and durability. We reinforced our section using a combination of free and continuous fibers. So, in addition to weaknesses in the ITZ, debonding may occur between the matrix and the fiber reinforcement.

Prior attempts by others to improve bonding in these critical areas have been limited in scope and did not significantly alter the nature of the interaction between the aggregate and matrix. In contrast, our

team relied on an advanced strategy involving molecular and atomic interactions. We studied our materials to understand the strength, failure, and bonding characteristics of our composite section. A stress analysis was performed using the transform section theory, and we employed a dynamic finite element program to study our boat’s modal response. After computing the weight for optimal performance, we constructed our boat in a female mold, employing adaptive reinforcement to resist stress reversals.

Structural Analysis: Transform section theory

and dynamic FEA. Structural Design: Stress transfer with molecular and atomic i teractions. n

Construction: Dynamically tuned hull

built with adaptive reinforcement. Management:

Experienced leadership with a focus on

professionalism and green building practices.

To address the issue of project management, we elected Mr. Todd Watts to the position of Chapter President. Mr. Watts is a graduate student currently studying Engineering Management, a Project Manager for the Army Corps of Engineers, a registered PE, and a certified Project Management Professional. To train our team members, we utilized the experience of our alumni and selected one of our past Concrete Canoe Chairmen, Mr. Jackie Whitaker, to oversee the design, testing, and construction effort. Mr. Whitaker is a LEED Accredited Professional and he worked throughout the year to educate our team members on sustainability and “green” building practices. Except for cement, 100% of the binders and all of the aggregates in our canoe are recyclables.


“It’s what’s inside that counts.” 1 Analysis

Analysis We welcome this year’s requirement for a common hull design

because it allows direct comparisons to be made between different teams’ choices of critical parameters and design requirements, their hydrodynamic designs, structural analyses, concrete technology and managerial strategies, as well as their canoes’ construction, compliance to dimensional requirements, and overall performance. In this report, we will show that while our entry might look deceptively like our competitors’ canoes, its unique attributes place it a league ahead in both design and performance.

Looks can be deceiving: Our boat is significantly different from all others.

Critical Parameters: Many of the methods used and assumptions made to design traditional reinforced concrete structures cannot be applied to produce advanced cementitious composites (Vaughan and Gilbert 2001). In the design of our concrete canoe, for example, the structure cannot be allowed to crack, so knowledge of the concrete compressive strength is not as important as it is in other applications. It is the elastic modulus and tensile strength of the cementitious matrix, as well as the bond strength between the matrix and the reinforcement, that impact our design most. As mentioned below, we relied on material symmetry and multi-layered reinforcement to maintain structural integrity, and took advantage of molecular and atomic interactions to strengthen the ITZ and the matrix/fiber interface.

Even though the exterior dimensions of this year’s hull are fixed (NCCC Rules 2009), boats of similar shape will not be equally efficient because their structural integrity, dynamic response, and modal parameters will depend on the density, stiffness, and position of the materials employed during fabrication, as well as the physical constraints imposed by structural members and boundary conditions encountered while racing (Gilbert et al. 2006).

Canoe mass (weight) is one of the most critical parameters and we established ours at 97.5 kg (215 lb) based on buoyancy calculations involving our women’s sprint team. We needed to have sufficient draft so that the bow was slightly submerged with the waterline extending along the entire length of the canoe. This critical racing condition makes the hull displace water efficiently and allows all of our teams to achieve maximum hull speed by having the largest possible waterline length.

For a given reinforcement and geometrical configuration, the stiffness ratio of the reinforcement to the matrix controls the stress transfer (Biszick and Gilbert 1999) and the choice of materials alters the characteristics of the fundamental modes (Ooi et al. 2004). As explained below, we dynamically tuned our hull to lower our canoe’s deceleration and increase our teams’ average velocity.

Major Considerations: Strength, stiffness,

geometry, and weight.

Service Loads: The stress distribution in a concrete canoe changes as it is transported and paddled. During past competitions, our competitors have studied these loading conditions using numerical techniques (Design Reports 2009) but ambiguities in results reported for critical loads indicate a lack of sophistication and the need for making further refinements in their models.

Our predecessors developed an empirical method by mounting strain gages on a composite prototype (Team UAH 2006). We followed their lead and mounted gages on our prototype at all of the critical locations reported by the major competitors (Design Reports 2009). After testing our boat under transport and racing conditions, we unequivocally proved that the peak strain occurs directly beneath the bow paddler during the men’s endurance race. We modeled this critical section by pure bending and loaded a test plate, having a cross section identical to that used in our prototype, until the critical strain was reached. For our men’s endurance team, we determined that the critical service load was equivalent to a 0.28 N-m (2.5 in-lb) moment applied to a 2.54 cm (1 in.) wide plate.

Methods of Analysis: Strain gages on prototype; test plate in pure bending.

Composite Lay-Up: Our structural design relies on the large difference in stiffness between the constituents in a composite section to drive the internal stress from a flexible cementitious matrix to multiple layers of a relatively stiff graphite mesh. We recognized that the thickness of our canoe would ultimately depend upon the specific weight of our concrete. But we felt that we could easily place a 9.53 mm (0.375 in.) thick composite section and used this value for design and testing purposes. We reinforced the section with three layers of mesh and placed materials symmetrically to form an adaptive section optimized to resist stress reversals (Biszick and Gilbert 1999; Biszick et al. 2006).

We selected the elastic modulus of last year’s mix [E = 2.76 GPa (400 ksi)] as a benchmark, and positioned two layers of mesh as close as possible to the upper and lower surfaces of the section to increase the moment of inertia.

Assumptions: 9.53 mm thick section; matrix with elastic modulus 2.76 GPa.


“It’s what’s inside that counts.” 2 Development and Testing

Dynamic Characterization: We fed the dimensions from our design drawings and the mechanical material properties of our section into a dynamic finite element model based on classical laminated plate theory (i.e., using NASTRAN software; Ooi et al. 2004). The model showed that the first mode was anti-symmetrical torsion while the second mode was “flutter” bending.

Fibers in the outermost layers were aligned longitudinally and transversely with respect to the longitudinal centerline of the canoe so that they were positioned in the principal stress directions. We added a third layer of reinforcement at the center of the section with fibers oriented at plus and minus 45° to the structural axes. The additional layer and its strategic rotation increase the torsional stiffness and achieve a better balance between the fundamental modes, enabling the strain energy stored in the deformed shape to be more efficiently converted into forward propulsion (Team UAH 2005).

Computer simulations show our boat’s movement mimics the locomotive motion of aquatic creatures and our lay-up resembles the semi-helically wound configuration found in a shark’s skin. Although we knew that the natural frequencies associated with the fundamental modes would be relatively high (~ 15-20 Hz) compared to our stroke rate (~ 1 Hz), our boat will decelerate less between strokes resulting in the higher average velocity that it will take for us to win in the water.

Stress Analysis: We assumed that bending was the primary mode of loading and applied the standard transform section theory to perform a stress analysis using an Excel spreadsheet. For the critical load condition, the maximum tensile and compressive stresses in our concrete mix were 1.19 MPa (173 psi) and the maximum stresses in the reinforcement were 67.7 MPa (9.82 ksi). The graphite has a high tensile strength [3.65 GPa (530 ksi)] and, with a margin of safety of 54, there is little chance that the fibers will break. Since the compressive strength of a concrete mix is always higher than its tensile strength, our design relies on placing a 97.5 kg (215 lb) boat with a relatively flexible concrete mix that has sufficiently high tensile and bond strengths to

ithstand the critical loading.

Computational Tools: AutoCAD (hydrodynamics);

NASTRAN (dynamics); Excel (stres sis). s analy Requirements: A boat

having a mass of 97.5 kg with a composite section

that can withstand 0.28 N-m per 2.54 cm.w

Development and Testing Reinforcement Compliance: Team UAH introduced graphite fibers into the competition sixteen

years ago (Team UAH 1993) because they are ten times stronger and five times lighter than steel. As described in our lay-up procedure (see page 1), we positioned three layers of fiber mesh in the composite section. Each layer of reinforcement consists of non-impregnated graphite fibers with 3,000 fibers per tow, spaced at 3.18 mm (0.125 in.) intervals. Each tow is 0.19 mm (0.0075 in.) thick by 1.07 mm (0.042 in.) wide. The manufacturer reports the elastic modulus and tensile strength of the fiber to be 231GPa (33.5 Msi) and 3.65 GPa (530 ksi), respectively.

We calculated the minimum percent open area (POA), defined in Section 4.3.2 (NCCC Rules 2009), at 44 percent. We performed reinforcement thickness measurements in accordance with Section 4.3.1 (NCCC Rules 2009) and established the maximum reinforcement/thickness ratio for our final design to be 0.133. The procedures and results of the experimental tests that we conducted are included in our Engineer’s Notebook (Team UAH 2009).

Primary Reinforcement: Continuous graphite fiber mesh with a POA of 44%.

Mix Design: Although useful as a benchmark for structural design purposes, last year’s mix did not meet many of the requirements for the current competition. So we followed a comprehensive trial and error mix design process to arrive at a final mix. We began by combining equal parts of portland cement and fly ash to bind a matrix that consisted of cenospheres, water, latex, and air entrainment admixture. Our goal was to produce the lightest, strongest, and most flexible mix possible so our composite section could safely withstand the critical load. We geared our effort toward the current trends in industry to go “green” with a focus on sustainability in design and construction. Our final mix is “as green as it gets,” since 100 percent of the binders (excluding cement) and all of the aggregates are recyclables.

Bond strength is very important and, as our work progressed, we realized a poly(vinyl butyral) (PVB) admixture and poly(vinyl alcohol) (PVA) fibers could be used to strengthen both the ITZ (Breton et al. 1993; Scrivener et al. 2004; Zheng et al. 2005) and the overall composite section (Friedrich et al. 2005). We evaluated a total of 83 trial mixes before selecting the one used to place our canoe.

The final mix was designed and selected based on a method developed for fabricating structurally equivalent reinforced concrete composite plates (Raut et al. 2004). We placed an older mix that had a


“It’s what’s inside that counts.” 3 Development and Testing

known elastic modulus over our reinforcement scheme and loaded a specimen [10.2 cm (4 in.) wide by 35.6 cm (14.0 in.) long] to failure by subjecting it to pure bending (ASTM C78). As we varied the constituents, we were able to determine the elastic modulus of a new mix by comparing the center deflections of the new plate with those of the old one. We placed our plates on a vertical template and measured the thickness variations from top to bottom so that shrinkage and consolidation could be taken into account during the placement of our concrete canoe.

This procedure allowed us to perform concrete mix design while studying, concurrently, the impact a change in constituents had on the overall structural performance of our composite. Once we had achieved the desired composite properties, we tested the matrix alone.

Binder Selection: We used portland cement (ASTM C150) and Class C fly ash (ASTM C618) as binders in the final mix and made sure all requirements on mass were satisfied (Section 3.3.1; NCCC Rules 2009). When mixed with lime and water, fly ash forms a cementitious compound (Joshi and Lohtia 1997). The particles are typically a few micrometers in diameter and nearly spherical in shape (Majko 2007). They can significantly alter material microstructure and mechanical properties and their addition favorably impacts environmental sustainability (Yang et al. 2007). In our case, the relatively small particles increase bond strength and fill in microscopic voids in the matrix, helping us to maintain the structural integrity of our composite section.

Aggregate Selection: We used cenospheres as aggregates in the final mix and made sure all requirements imposed on aggregate proportioning were satisfied (Section 3.3.2; NCCC Rules 2009). As described on page 7, the cenospheres allowed us to meet the requirement to use recycled materials. They are thin-walled glass spheres comprised primarily of silica and alumina that are lightweight, inert, and hollow (Sphere Services 2009). The spheres are harvested from the surfaces of ash ponds and then processed and marketed for performance enhancement in many different products.

While designing our mix, we strove to produce the smallest possible particle size distribution (see Appendix C) by allowing only 95% (by weight) of the particles to remain on the No. 100 sieve. This increased workability, allowed us to place thinner layers, and made it possible for us to easily patch our canoe. The smaller particles that constituted the remainder of the composite aggregate created a dense grain structure that helped prevent graphite fibers from buckling on the compressive side of the composite section. Aggregates were batched at hydroscopic moisture content (ASTM C127).

Sustainability: Excluding cement, all of our binders and aggregates are

recyclables.

Secondary Reinforcement: Debonding may occur between the matrix and our fiber reinforcement due to shear deformation and fiber sliding (Friedrich et al. 2005). To counteract the potential debonding, we added poly(vinyl alcohol) (PVA) fibers to help bridge micro-cracks and strengthen the matrix. The fiber has a high tensile strength, a high modulus, and low specific gravity. PVA is obtained from poly(vinyl acetate) which is readily hydrolysed by treating an alcoholic solution with an aqueous acid or alkali (Zheng and Feldman 1995). The hydrophilic nature of PVA fibers cause them to bond well with the cementitious matrix (Wang and Li 2006). The formation of this microstructure is attributed to the effect PVA has on the nucleation of CH and CSH at the fiber surface and on the presence of polymer around the fibers (Wang and Li 2006; Feldman and Barbalata 1996).

Admixtures: We used a latex admixture to enhance the bonding and flexibility of our matrix and added an air entrainment admixture (ASTM C260) at 1774 ml (60 oz) per 45.4 kg (100 lb) of cementitious materials (15 times the manufacturer’s recommended dose) to reduce weight and achieve the minimum air content (Section 3.34, NCCC Rules 2009). The overdose had no detrimental effects.

Butvar B-79 (PVB) was employed to strengthen the ITZ and was selected because of its binding efficiency, adhesion, toughness, flexibility, and waterproofing properties (Lavin et al. 2008). The product comes in the form of a lightweight solid white powder that is completely insoluble in cement-water-mixes and does not crosslink or form polymers or covalent bonds. It is an already polymerized plastic similar to cellulose and contains hydroxyl groups that have the potential to form a hydrogen bond between molecules, or within different parts of a single molecule (see page 7 for additional details).

Strategy: A PVB admixture and free PVA fibers were used to strengthen the

composite.

Testing: We studied micro-mechanical behavior and composite failure under combined loading by testing end-loaded cantilevers (based on ASTM D747). Then, we tested concrete specimens to obtain the elastic modulus [3.44 GPa (499 ksi)] and 7-day tensile strength [4.83 MPa (700 psi)].

We cast concrete cylinders (ASTM C31) and performed compression tests (ASTM C39) to get the


“It’s what’s inside that counts.” 4 Project Management and Construction

28-day compressive strength [13.10 MPa (1900 psi)]; and measured the unit weights [1094.6 kg/m3 (68.4 lb/ft3) and 1101.1 kg/m3 (68.7 lb/ft3)] (ASTM 138) and air contents [6.6 % and 6.1%] by the gravimetric method, for the mixes described on pages B1 and B2, respectively.

Finally, we computed the thickness [1.27 cm (0.5 in.)] required to obtain the target weight, based on the combined weight of the concrete, reinforcement, flotation, stain, sealant, graphics, and two women paddlers. Although our main structural mix (see page B2) had an elastic modulus 1.25 times that assumed for our benchmark, when we tested a 1.27 cm (0.5 in.) plate in pure bending, our composite section resisted a moment of 20.2 N-m (178.6 in-lb) applied to a 10.2 cm (4 in.) wide plate giving us a margin of safety of 17.9!

Final Design: Thickness adjusted to obtain target weight; margin of safety

equal to 17.9. Project Management and Construction

Following last year’s unsuccessful campaign, the alumni that attended the conference scheduled a meeting with our faculty advisors to discuss why things didn’t go well and how they might help. Several problems were identified, particularly in the areas of fundraising, faculty support, safety, and project management. In response, our alumni made several commitments. They agreed to help raise funds, supervise concrete canoe design and construction, and train the paddling team. A past president, who had recently returned to study Engineering Management, volunteered to become president again, if the membership was agreeable. He prepared a position paper outlining his goals and expectations while explaining that he intended to train his fellow officers so they could take the helm in future stints. The paper was sent by email to all Chapter members and the response was so overwhelming that he was later elected unanimously by affirmation.

Alumni Support: Serious commitments were made to ensure our success.

Fundraising: The advisors explained that during the 2007-2008 academic year UAH was facing large budget cuts and strict guidelines had been placed on fundraising by the administration. The Chapter was barred from approaching all potential sponsors, and was therefore unable to obtain the physical resources and financial backing it needed. This year, with the restriction on contacting donors eased, the team was able to utilize their alumni’s experience with vendors and marketing to prepare a professional fundraising packet that showcased the Chapter’s contributions to the Civil Engineering community. While the economic downturn has limited the amount of funding available, we improved our Chapter’s relationship with both the university and local businesses, and created fundraising and professional development opportunities for the future. Our efforts paid off immediately prior to the regional conference when we secured the largest single donation in our Chapter’s history. The majority of the materials required for construction of the mold and concrete canoe (listed in the bill of materials on page 10) were either salvaged or donated. We spent an additional $4,600 on materials and supplies.

Faculty Support: Last year, increased faculty workload resulted in less time for advisor interaction with Chapter members. This year, we worked to establish a plan and schedule prior to the start of the school year. This plan required regular briefings, so the faculty advisors were able to schedule meetings with the team leaders well in advance.

Safety: During construction of the 2008 practice boat, the Canoe Chair nearly lost his thumb while working with a table saw. The accident itself, and the subsequent infection and rounds of surgery, completely removed him at a critical point in the project. This year, we strictly enforced a safety policy requiring at least two team members to be present at all times and mandated that all chapter members working on equipment take a rigorous shop course. Additionally, no power tools may be operated in the work area without the Canoe Chair or the Chapter President present. We stressed the responsibility of working safely, used personal protective equipment, and followed guidelines suggested by the Occupational Safety and Health Administration (OSHA 2009). All of our members were required to attend seminars presented by the UAH Environmental Health and Safety Office. We secured manuals and educational safety videos to supplement this training and reviewed the Material Safety Data Sheet for each material with which we worked.

Challenges Faced: Fundraising, technology

transfer & documentation.

Project Management: Last year, there was no redundancy in the team leadership. Knowledge resided with specific individuals with little overlap; therefore, the sudden absence of the Canoe Chair threw the team into turmoil. Individuals who had previously been in supporting roles were suddenly cast into leadership positions without the necessary knowledge or experience. This year, we elected



experienced leaders with the specific intention of training and developing new chapter leadership. Rather than relying on a novice to gain on-the-job knowledge, we’ve learned that leaders produce leaders. Our emphasis on training means we have “understudies” available to take over when necessary.

In previous years, we compartmentalized the project by assigning each task to a different team. This method relied heavily on each team leader having a high level of experience, organization, and communication skills in order to integrate each team’s product into the whole. Given the small size of our chapter this year, we simply did not have enough team members with that skill set.

This year, we used a systems approach to look at the project holistically to see where the overlaps and interactions lay. At our first chapter meeting, we formed a coordinating committee consisting of the Project Manager (chapter president), Project Engineer (Concrete Canoe Chair), and consultants (faculty and graduate advisors). These key stakeholders acted as a configuration control board to manage scope and monitor project status, budget, and corrective actions throughout the project.

While our new approach does increase the workload for key team members, we’ve seen a significant improvement in efficiency and decision-making. By looking at the big picture, we were able to minimize the conflicts and misunderstandings that have crippled our efforts over the last few years. We are not only improving our chapter this year, but we are also building a foundation for future efforts.

Skills Developed: Project planning, risk management,

safety & teambuilding.

Teambuilding: The Project Manager and Project Engineer evaluated the strengths and weaknesses of past teams and elected to follow the team building approach developed by recent teams at UAH. To this end, the coordinating committee asked all team members to go through a corporate training and development course offered by an Air Force veteran turned behavioral consultant (Bentley 2009). As part of the course, a DISC profiling system (Inscape 1996) was used to uncover our strengths, weaknesses, motivations, and behavioral tendencies. Each team member discovered how he or she tended to behave under stress, in a team, when in conflict, when communicating, when fearful, when avoiding certain activities, and when problem solving. More important, they learned how others tend to react in the same situations. Given this insight into our teammates, we learned how to interact efficiently by utilizing each other’s strengths and compensating for each other’s weaknesses.

We quickly realized it’s what’s inside that counts, and subsequently learned to identify the attributes required to become not only champions but also successful engineers: initiative, integrity, innovation, determination, leadership, and teamwork. You’ll see these listed on the interior of our boat.

Critical Path: With the help and guidance of our alumni, the coordinating committee created an organizational breakdown structure (OBS) in which organizational relationships were identified and used as the framework for assigning work responsibilities. Milestones were established and the critical path was determined by defining tasks that had no float. The critical path and the milestones are displayed on the project schedule (see page 9). Table 1 below highlights the major tasks. Table 1: Project Milestones and Differences

Milestone Difference Reason Structural Analysis 1-week delay Stress Analysis

Mix Design 7-week delay Material Procurement Construction 3-week delay Mold Construction

Documentation 1-week delay Mold Construction

The coordinating committee studied the projected duration of each critical path activity, overlaps in activities in the schedule, and the milestones experiences by previous teams, and they modified our schedule to reduce the risks of overrun. Each major milestone marked a significant transitional event for the project. Although leadership during design and construction was turned over to individuals with expertise and experience, a conscientious effort was made to recruit, retain, train, and rely on new members. Recognizing the possibility that future events may cause adverse effects, we adopted a policy of continuous risk management (Murphy et al. 2006). We applied the underlying principles for decision-making in many phases of the project ranging from team organization and mix design to construction and safety. Risks were resolved or, when they turned into problems, handled.

Work-hours were compiled for each major activity prior to the conference competition: 220 for structural analysis, 400 for mix design and structural testing, 1,500 for canoe construction, and 1,000 for paddling. Approximately 380 hours were spent during this period on other tasks including management, fund raising, and documentation. We expect to spend an additional 1800 hours preparing for nationals.



Mold Construction: For the past thirteen years, Team UAH has placed our concrete canoes over male molds. This year, we decided to place our canoe within a female mold. This process eliminated waste during placement, since all concrete remained in the boat. As compared to working with a male mold, concrete settled to the bottom of the hull keeping the center of gravity lower. The process also allowed us to capitalize on shrinkage during form removal. It afforded an excellent outer surface that required little sanding and the ability to precisely replicate the given dimensions while making the adjustments in thickness required to obtain our target weight. The true shape eliminated the need for checking dimensional tolerances after the fact using time consuming and complex contouring methods.

We began by modifying the supplied AutoCAD file that was provided to us by the rules committee by including an offset equal to the thickness of the facing materials that were to be used during mold construction. We produced design drawings at cross sections located at 30.5 cm (12 in.) intervals along the length and used them to create 1.27 cm (0.5 in.) thick plywood templates that we mounted and aligned on a wooden strongback. We then ripped 3.8 cm (1.5 in.) wide strips from 0.64 cm (0.25 in.) thick plywood sheets and nailed the strips to the inner surfaces of the templates. We further refined the shape using drywall compound and relied on spotlighting techniques to identify discontinuities. Problem areas were marked and filled with drywall until all discontinuities were removed. Once the mold was finalized, we applied two layers of fiberglass to harden the surface. Foam cross sections were fabricated and inserted into the mold to check for dimensional accuracy throughout the mold construction process.

We constructed a composite prototype to verify the critical load and serve as a practice boat. After evaluating our design, we coated the interior of the mold with automotive primer and clear coat. The clear coat was then buffed smooth to prevent the concrete from adhering to imperfections on the surface.

Quality Control: We strove to produce a stunning product and chose not to include inlays to keep it defect free. In addition to completely changing our mold construction scenario, we enacted new procedures for testing, documentation, concrete mixing, and placement. Our quality control program relied on training sessions and advanced planning for quality assurance. Everyone involved was required to attend informational sessions to ensure a consistent level of education, experience, and attention to detail. Tasks such as proportioning materials were completed in advance to ensure efficiency throughout the placement process.

To ensure a uniform hull thickness, we developed a series of instruments, inspired by bluetops, to gauge the thickness of each layer of concrete. During construction, measurements were taken in a 15.24 cm (6 in.) grid to identify high and low spots. These significantly reduced the amount of sand and fill necessary during the finishing stage and brought us to within one percent of our target weight.

Problems Solved: Quality control/assurance brought us to within 1% of

our target weight.

Canoe Construction: To begin, the team prepared several small batches of white concrete mix and used drywall knives to level the concrete to the interior of the mold. Once the first layer of concrete cured to firmness, the first layer of graphite mesh was draped in the mold, taking care to align the fiber with the axis of the canoe. A wooden strip was added around the upper perimeter of the canoe to serve as added flotation and as a gunwale. The second layer of gray concrete was placed carefully over the mesh, to avoid pulling the fibers out of place. After the second layer of concrete cured firm, we draped the second layer of graphite mesh into the mold at a 45 degree angle to the long axis of the canoe and placed another layer of gray concrete. The third layer of graphite reinforcement was then added along with foam floatation and the final layer of white concrete was placed over the entirety of the interior.

The foam flotation was installed in the bow and stern and secured in place using small sheets of graphite mesh. The gunwale was finished by trimming the overhanging reinforcement and wrapping it around the wood strips, then placing concrete over the entire configuration. The additional reinforcement over the flotation is intended to minimize cracking.

Since the latex spheres in the mix coalesce to form a film that coats the aggregate particles and the hydrating cement grains, the water required for hydration is held in the system (Biszick and Gilbert 1999). So, we simply left our canoe to dry. We hand-sanded the interior of the canoe while it was still on the mold and filled any remaining voids with our main structural mix. The bottom was left rougher than the sides to help hold our seats in place during the races. We removed the canoe from the mold 17 days after placement and discovered that we had to do a minimal amount of finishing on its exterior surface.

During our corporate training program, we learned that people often wear masks to hide their critical flaws. Following the adage that “less is more,” we decided to feature the natural beauty of our canoe by removing masks from its surfaces. To that end, we kept stains and graphics to a minimum and applied a clear sealer that met ASTM C1315 standards, according to manufacturer’s recommendations.

Team UAH 2009 Concrete Canoe Design Report “ITZ Civilized

“It’s what’s inside that counts.” 7 Innovation and Sustainability

Innovation and Sustainability

Innovation: All of our innovations reflect this year’s theme: “It’s what’s inside that counts.” As far as our boat is concerned, we incorporated advanced design concepts and defined a target weight, employed reverse engineering for mix design, and developed novel construction methods that allowed us to achieve our design goals. We built a “natural” looking product having very few flaws and trust that our “no frills” approach (no inlays, minimal attributes, and clear sealant) will be appreciated.

Our observation that “looks can be deceiving” is not only pertinent to our hull but to ourselves. By submitting to a corporate training program, we gained valuable insight into our personal makeup and developed a better appreciation for team dynamics. The manner in which we elected our president was very different and his position paper established completely new directions for project management, recruitment, fund raising, mentoring, and technology transfer. We strengthened our safety program, relied on risk management to maintain equilibrium, and improved quality assurance and control.

Major Breakthrough: Our major innovation was the development of a lightweight, high-performance cementitious composite that capitalized on the interfacial bonding that takes place in conjunction with our admixture Poly(vinyl butyral) (PVB) granules and free-fiber reinforcement [Poly(vinyl alcohol) (PVA) fiber]. Both PVB and PVA contain hydroxyl groups that have the potential to form a hydrogen bond between molecules, or within different parts of a single molecule. This unique feature provides remarkable changes in the surface bond strength, not only between the aggregate and the matrix, but also between the fibers and the matrix. Additionally, the ether oxygen functional groups act as a weak base that potentially interacts with Lewis acids in cement paste components like CSH.

PVB is a mixed hydrophilic hydrophobic molecule supplied as a water insoluble amorphous granule soluble only in organic solvents yet which partially hydrates in water. Its unique binding characteristics can be used to design mixes with distinctive properties, such as those that do not explosively fracture when impacted (Gilbert et al. 2008). The interfacial transition zone (ITZ) is characterized by the prevalence of calcium hydroxide and higher porosity, and is the weakest region in a concrete structure. Our addition of Butvar is in stark contrast to traditional methods that have been applied to improve the aggregate/matrix bonding in the ITZ, such as reducing the size of the aggregates (Akçaolu et al. 2002; Akçaolu et al. 2004), using basalt and quartzite as aggregates (Tasong et al. 1999), or replacing the cement with ultrafine additions of constituents, such as silica fume and metakaolin (Bentz 2000; Asbridge et al. 2004; Poon et al. 2001). These traditional methods are limited in scope, since they do not significantly alter the nature of the interaction between the aggregate and the matrix.

The bond strength between traditional steel and glass fibers and a traditional cementitious matrix is limited. Our addition of PVA fibers capitalizes on their hydrophilic nature to create a good bond with the cementitious matrix. The PVB and PVA fiber also have the potential to interact. Under light microscopy, this combination has been observed as PVB beads on strings of PVA fiber (Gilbert et al. 2008). Physically, we are suggesting that our PVA fiber interacts with the cement paste and also with the relatively high volume fraction admixture PVB. Our high margin of safety (17.9) reinforces this view, indicating that we have made a major breakthrough in concrete technology.

Sustainability: Sustainability is an ability to “meet the needs of the present without compromising the ability of future generations to meet their needs” (WCED 1987). Our concrete mix is more sustainable than most, since it relies on fly ash as a binder and includes cenospheres as the aggregate. Fly ash, a residue generated by the combustion of coal, is the largest byproduct of coal-fired power plants. Today it is recovered by electrostatic precipitators or filter bags, as opposed to being released into the atmosphere. Cenospheres occur naturally in fly ash and are microscopic spheres of silica and alumina filled with air or gases. Typically harvested from the surfaces of ash ponds, they have a ready, high value market for use as fillers in both construction and other industries, and new applications, such as ours, are continually being developed. Currently, PVB is recycled from automotive windshields.

Sustainability means more than simply using recycled materials in a concrete mix. This year, we incorporated recycling programs into our daily routines and did our best to reduce our waste stream by sorting and reusing where possible. We encouraged our chapter members to car pool, ride bicycles, and walk to chapter meetings. We used electronic venues such as Facebook, Gmail, and our websites to advertise our chapter meetings and gatherings. During the process of drafting this design report we relied on email and computer based reviews to minimize wasted paper. We estimate that this alone has saved nearly 1,000 pages of paper. Additionally, all our submittals are printed on paper composed of 35% recycled materials. Incidentally, we estimate that if this competition would eliminate paper-based reports, it could save nearly 15,000 pages of paper along with the fuel used for shipping.


Organization Chart

2009 Team UAH - Coordinating Committee

Managed all aspects of the concrete canoe competition.

Project Manager: Project Engineer: Coordinated strategic planning, recruitment, Coordinated design, construction, and project management. Involved in all and crew training. Involved in all aspects of the project. aspects of the project

Consultants: John Gilbert, Houssam Toutanji, Kirk Biszick,

Todd Watts Sarah Yeldell, Jackie Whitaker Matt Pinkston

Strategic Planning Created organizational breakdown structure; selected theme; guided

fundraising; risk management; and quality assurance.

Leader: Todd Watts

Composite Design Studied geometry, strength, and stiffness; designed matrix (mix) and composite; performed tests.

Engineer: Matt Pinkston

Mold Construction Constructed female mold to meet strict dimensional requirements


Structural Design and Testing Designed a strong, flexible, and dynamically efficient concrete canoe; developed testing programs (modal, structural, hydrodynamic, etc.); and, verified results.

Supervisory Engineer: Matt Pinkston

Recruitment Recruited, retained, and trained new members; coordinated and

scheduled task work with veterans.

Team Leader:

Jorge Cacciatore

Trainees: Bert Baker, Jennifer Bowers,

Stephanie Buckner, Ryan Miller, Cristina Poleacovschi, Seth

Martin, Michael Royster, Charlsie Smith, Leon Waters, Amber Wise.

Concrete Canoe Constructed “ITZ Civilized” in a safe working environment with excellent quality control.


Prototype Fabricated a male mold; produced

and maintained a composite prototype to test hull design and

train crew.


Documentation Documented the project, compiled information, collected data, wrote

design report, and prepared engineer’s notebook.

Engineer: Cristina Poleacovschi

Oral Presentation Developed theme and scripted

oral presentation.

Team Leader: Matt Pinkston

Participants:

Jennifer Bowers, Jorge Cacciatore, Matt Pinkston,

Charlsie Smith, Amber Wise.

Crew Training Trained paddlers, selected

crewmembers for the competition.

Co-Captains: Jorge Cacciatore Jennifer Bowers

Paddlers:

Jennifer Bowers, Stephanie Buckner, Jorge Cacciatore, Ryan

Miller, Matt Pinkston, Michael Royster, Charlsie Smith, Amber

Wise.

Competition Readiness Designed and constructed

cutaway cross-section, stands, tabletop display, etc.

Engineer: Todd Watts

“It’s what’s inside that counts.”

“It’s what’s inside that counts.” 8 Organization Chart


“It’s what’s inside that counts.” 9 Project Schedule

Project Schedule


“It’s what’s inside that counts.” 10 Design Drawing and Bill of Materials

Design Drawing & Bill of Materials


“It’s what’s inside that counts.” A1 References

Appendix A - References Appendix A - References Appendix A - References Akçaolu, T., Tokyay, M., Çelik, T. (2002). “Effect of coarse aggregate size on interfacial cracking under uniaxial compression,” Materials Letters, Vol. 57, No. 4, pp. 828-833.

Akçaolu, T., Tokyay, M., Çelik, T. (2004). “Effect of coarse aggregate size and matrix quality on ITZ and failure behavior of concrete under uniaxial compression,” Cement and Concrete Composites, Vol. 26, No. 6, pp. 633-638.

Asbridge, A.H., Chadbourn, G.A., Page, C.L. (2001). “Effects of metakaolin and the interfacial transition zone on the diffusion of chloride ions through cement mortars,” Cement and Concrete Research, Vol. 31, No. 11, pp. 1567-1572.

ASTM C31. “Standard practice for making and curing concrete test specimens in the field,” C31-03, on line at: http://www.astm.org/. ASTM C39. “Standard test method for compressive strength of cylindrical concrete specimens,” C39-05, on-line at: http://www.astm.org. ASTM C78. “Standard test method for flexural strength of concrete (using simple beam with third-point loading),” C78-02, on line at: http://www.astm.org/. ASTM C127. “Standard test method for density, relative density (specific gravity), and absorption of coarse aggregate,” C127-04, on-line at: http://www.astm.org. ASTM C138. “Standard test method for density (unit weight), yield, and air content (gravimetric) of concrete,” C138-01, on line at: http://www.astm.org/.

ASTM C150. “Standard specification for Portland cement,” C150-05, on line at: http://www.astm.org/.

ASTM C618. “Standard Specification for coal fly ash and raw or calcined natural pozzolan for use in concrete,” C618-08a, on line at: http://www.astm.org/.

ASTM C260. “Standard specification for air-entraining admixtures for concrete,” C260-01, on line at: http://www.astm.org/. ASTM C1315. “Standard specification for liquid membrane-forming compounds having special properties for curing and sealing concrete,” C1315-03, on-line at: http://www.astm.org. ASTM D747. “Standard test method for apparent bending modulus of plastic by means of a cantilever beam,” D747-02, on line at: http://www.astm.org/. Bentley, J. (2009). “Training and development, DISC personality tests, corporate training,” Power2Transform (P2T), on line at: http://www.power2transform.com. Bentz, D.P. (2000). “Influence of silica fume on diffusivity in cement-based materials. II. Multi-scale modeling of concrete diffusivity,” Cement and Concrete Research, Vol. 30, No. 7, pp. 1121-1129. Biszick, K.R., Gilbert, J.A. (1999). “Designing thin-walled, reinforced concrete panels for reverse bending," Proc. of the 1999 SEM Spring Conference on Theoretical, Experimental and Computational Mechanics, Cincinnati, Ohio, June 7-9, 431-434. Biszick, K.R., Toutanji, H.A., Gilbert, J.A., Matotta, S.A, Ooi, T.K. (2006). “Evolution of strategically tuned absolutely resilient structures (STARS),” Proc. of SEM Annual Conference & Exposition on Experimental and Applied Mechanics, Saint Louis, Missouri, June 5-7, Paper No. 32. Breton, D., Carles-Gibergues, A., Ballivy, G., Grandet, J. (1993). “Contribution to the formation mechanism of the transition zone between rock-cement paste,” Cement and Concrete Research, Vol. 23, No. 2, pp. 335-346. Design Reports. (2009). “NCCC design reports (2000-2008),” concretecanoe.org, courtesy of UW, on line at: http://www.cae.wisc.edu/~canoe/Design%20Papers/Design_Papers.htm.



Feldman, D., Barbalata, A. (1996). “Synthetic Polymers: Technology, Properties, Applications, Chapman and Hall,” London, pp.101.

Friedrich, K., Fakirov, S., Zhang, Z. (2005). “Polymer Composites: From Nano-to-Macro-Scale,” Springer Inc., New York, pp. 129-130.

Gilbert, J.A., Ooi, T.K., Engberg, R.C. (2006). “Modal analysis of a lightweight concrete canoe,” Concrete Canoe Magazine, Vol. 1, No. 1, pp. 21-27.

Gilbert, J.A., Biszick, K.R., Toutanji, H.A. (2008). "Strategically tuned absolutely resilient structures,” Phase II Final Technical Report, SBIR Contract No. W31P4Q-06-C-0448, U.S. Army Research, Development, and Engineering Command Aviation and Missile Research, Development, and Engineering Center, Redstone Arsenal, Alabama, October, 60 pages. Inscape. (2006). “The personal profiling system and models of personality research report,” Inscape Publishing, Item No. 0-232. Joshi, R.C., Lohtia, R.P. (1997). Fly ash in Concrete, Production, Properties and Uses, Taylor & Francis. Lavin, T., Toutanji, H., Xu, B., Ooi, T.K., Biszick, K.R., Gilbert, J.A. (2008). “Matrix design for strategically tuned absolutely resilient structures (STARS),” Proc. of SEM XI International Congress on Experimental and Applied Mechanics, Orlando, Florida, June 2-5, Paper No. 71. Majko, R.M. (2007). “Fly ash resource center,” information on coal combustion byproducts (CCBs), on line at: http://www.rmajko.com/. Murphy, R.L., Alberts, C.J., Williams, R.C. Higuera, R.P., Dorofee, A.J., Walker, J.A. (2006). “Continuous Risk Management Guidebook,” Carnegie Mellon University, information on line at: http://www.sei.cmu.edu/publications/books/other-books/crm.guidebk.html. NCCC Rules. (2009). “2009 American Society of Civil Engineers National Concrete Canoe Competition rules and regulations,” on line at: http://content.asce.org/conferences/nccc2009/rules.html. Ooi, T.K., Engberg, R.C., Gilbert, J.A., Vaughan, R.E., Bower, M.V. (2004). “Modal testing of a lightweight cementitious structure,” Experimental Techniques, November/December, pp. 37-40. OSHA. (2009). “Laboratories”; “Hazard Communication”; “Construction, Concrete Masonry”; “Personal Protective Equipment”; “Ventilation,” on line at: http://www.osha.gov. Poon, C., Lam, L., Kou, S.C., Wong, Y., Wong, R. (2001). “Rate of pozzolanic reaction of Metakaolin in high-performance cement pastes,” Cement and Concrete Research, Vol. 31, pp. 1301-1306. Raut, A. Gilbert, J.A., Ooi, T.K. (2004). “A method for producing structurally equivalent graphite reinforced cementitious composites,” Proc. of SEM X International Congress, Costa Mesa, California, June 7-10, Paper No. 173, 6 pages. Scrivener, K.L., Crumbie, A.K., Laugesen, P. (2004). “The interfacial transition zone (ITZ) between cement paste and aggregate in concrete,” Interface Science, Vol. 12, No. 4, pp. 411-421.

Sphere Services (2008). “Cenospheres, hollow ceramic microspheres,” product literature, on line at: http://www.sphereservices.com/ceno.html. Tasong, W.A., Lynsdale, C.J., Cripps, J.C. (1999). “Aggregate-cement paste interface: Part I. Influence of aggregate geochemistry,” Cement and Concrete Research, Vol. 29, pp. 1019-1025. Team UAH. (1993). “Rock-It,” ASCE/MBT national concrete canoe competition report, on line at: http://www.uah.edu/student_life/organizations/ASCE/Competition/1993.htm. Team UAH. (2005). “Imagineer,” ASCE/MBT national concrete canoe competition report, on line at: http://www.uah.edu/student_life/organizations/ASCE/Competition/2005.htm. Team UAH. (2006). “Full Spectrum,” ASCE/MBT national concrete canoe competition report, on line



at: http://www.uah.edu/student_life/organizations/ASCE/Competition/2006.htm. Team UAH. (2009). “ITZ Cilvlized,” University of Alabama in Huntsville concrete canoe competition engineer’s notebook. Vaughan, R.E., Gilbert, J.A. (2001). “Analysis of graphite reinforced cementitious composites,” Proc. of the 2001 SEM Annual Conference and Exposition, Portland, Oregon, June 4-6, 532-535. Wang, SX., Li, V.C. (2006). “Polyvinyl alcohol fiber reinforced engineered cementitious composites: material design and performances,” Proc. International RILEM Workshop on High Performance Fiber Reinforced Cementitious Composites in Structural Applications RILEM Publications SARL, In: Fischer, G., and Li, V.C. editors, RILEM Publications SARL, pp. 65-73. WCED (1987). “Our Common Future,” World Commission on Environment and Development Report, New York: Oxford University Press.

Yang, E., Yang, Y., Li, V.C. (2007). ““Use of high volumes of fly ash to improve ECC mechanical properties and material greenness,” ACI Materials Journal, Vol. 4, No. 6, pp. 303-311. Zheng, ZH., Feldman, D. (1995). “Synthetic fiber-reinforced concrete,” Progress in Polymer Science, Vol. 20, pp. 185-210. Zheng, J.J., Li, C.Q., Zhou, X.Z. (2005). “Characterization of microstructure of interfacial transition zone in concrete,” ACI Materials Journal, Vol. 102, No. 4, pp. 265-271.


Appendix B – Mixture Proportions

Mixture:Batch Size (ft3):

Specific Gravity *

Amount (lb/yd3) Volume (ft3) Amount (lb) Volume (ft3)

Amount (lb/yd3) Volume (ft3)

1 3.15 390.00 1.98 1.44 0.01 395.94 2.01

2 Fly Ash Class C 2.64 390.00 2.37 1.44 0.01 395.94 2.40

780.00 4.35 2.89 0.02 791.88 4.42

1 PVA Fibers 1.30 4.76 0.06 0.02 0.00 4.83 0.06

4.76 0.06 0.02 0.00 4.83 0.06

1Absorption 16.50 %

2 SG500 Cenospheres (< No. 100)

Absorption 16.50 %

455.00 9.11 1.69 0.03 461.93 9.25

1 200.53 3.21 0.74 0.01 203.58 3.26

Total Water Added for Aggregates 1 75.08 1.20 0.28 0.00 76.22 1.22

1 111.47 1.79 0.41 0.01 113.17 1.81

387.08 6.20 1.43 0.02 392.97 6.30

1 0.44 120.00 4.37 0.44 0.02 121.83 4.44

120.00 4.37 0.44 0.02 121.83 4.44

% Solids Amount (fl oz/cwt)

Water‡ in Admixture

(lb/yd3)

Amount (fl oz)


(lb)

Amount (fl oz/cwt)


(lb/yd3)1 6.7 60.00 1.73 60.002 26.9 250.00 111.47 7.22 0.41 250.00 113.17

Fibers

Total of All Fibers

Table 3.1 – Summary of Mixture ProportionsTeam UAH 2009 - Test Mix

ITZ Civilized Aesthetic ASTM C-138

0.100 Non-SSD Proportions as

Designed

Actual Batched Proportions

Yielded Proportions

Cementitious Materials

ASTM C150 White Portland Cement Type I

Total of All Cementitious Materials

AggregatesSG500 Cenospheres (> No. 100)

0.80 432.25 8.79

0.80 22.75 0.46 0.08 0.00 23.10

8.66 1.60

Batched Water^

Total Water from All Admixtures§

0.03 438.83

0.46

Total of All Aggregates

Water

0.50

Total Water

Solid AdmixturesButvar (B79)

Total of Solid Admixtures

Liquid Admixtures

MBAE 90 (AEA); Density, 8.5 lb/galLatex; Density, 10 lb/gal

Cement-Cementitious Materials Ratio 0.50 0.50

Slump, in. 1 1 1Water-Cementitious Materials Ratio 0.40 0.40 0.40

Density (Unit Weight), lb/ft3 67.37 68.40 68.40Air Content, % (ASTM C 128-97) 8.0% N/A 6.6%

Yield, ft3 27 0.099 27Gravimetric Air Content, % 6.6%

* For aggregates provide ASTM C 127 oven-dry bulk specific gravity.^ Excluding water added for aggregate absorption.‡ Water content of admixture.§ If impact on water-cementitious materials ratio is less than 0.01 enter zero.

“It’s what’s inside that counts.” B1 Mixture Proportions


Appendix B – Mixture Proportions

Mixture:Batch Size (ft3):

Specific Gravity *

Amount (lb/yd3) Volume (ft3) Amount (lb) Volume (ft3)

Amount (lb/yd3) Volume (ft3)

1 3.15 390.00 1.98 1.44 0.01 397.96 2.02

2 Fly Ash Class C 2.64 390.00 2.37 1.44 0.01 397.96 2.42

780.00 4.35 2.89 0.02 795.92 4.44

1 PVA Fibers 1.30 4.76 0.06 0.02 0.00 4.86 0.06

4.76 0.06 0.02 0.00 4.86 0.06

1Absorption 16.50 %

2 SG500 Cenospheres (< No. 100)

Absorption 16.50 %

455.00 9.11 1.69 0.03 464.29 9.30

1 200.53 3.21 0.74 0.01 204.62 3.28

Total Water Added for Aggregates 1 75.08 1.20 0.28 0.00 76.61 1.23

1 111.47 1.79 0.41 0.01 113.75 1.82

387.08 6.20 1.43 0.02 394.97 6.33

1 0.44 120.00 4.37 0.44 0.02 122.45 4.46

120.00 4.37 0.44 0.02 122.45 4.46

% Solids Amount (fl oz/cwt)


(lb/yd3)

Amount (fl oz)


(lb)

Amount (fl oz/cwt)


(lb/yd3)1 6.7 60.00 1.73 60.002 26.9 250.00 111.47 7.22 0.41 250.00 113.75

Fibers

Total of All Fibers

Table 3.1 – Summary of Mixture ProportionsTeam UAH 2009 - Test Mix

ITZ Civilized Structural ASTM C-138

0.100 Non-SSD Proportions as

Designed

Actual Batched Proportions

Yielded Proportions

Cementitious Materials

ASTM C150 Gray Portland Cement Type I-II

Total of All Cementitious Materials

AggregatesSG500 Cenospheres (> No. 100)

0.80 432.25 8.84

0.80 22.75 0.46 0.08 0.00 23.21

8.66 1.60

Batched Water^

Total Water from All Admixtures§

0.03 441.07

0.47

Total of All Aggregates

Water

0.50

Total Water

Solid Admixtures

Butvar (B79)

Total of Solid Admixtures

Liquid Admixtures

MBAE 90 (AEA); Density, 8.5 lb/galLatex; Density, 10 lb/gal

Cement-Cementitious Materials Ratio 0.50 0.50

Slump, in. 1 1 1Water-Cementitious Materials Ratio 0.40 0.40 0.40

Density (Unit Weight), lb/ft3 67.37 68.74 68.74Air Content, % (ASTM C 128-97) 8.0% N/A 6.1%

Yield, ft3 27 0.098 27Gravimetric Air Content, % 6.1%

* For aggregates provide ASTM C 127 oven-dry bulk specific gravity.^ Excluding water added for aggregate absorption.‡ Water content of admixture.§ If impact on water-cementitious materials ratio is less than 0.01 enter zero.

“It’s what’s inside that counts.” B2 Mixture Proportions


“It’s what’s inside that counts.” C1 Gradation Curve and Table

Appendix C – Gradation Curve and Table

Concrete Aggregate: Cenospheres

Sample Weight (g): 500

Specific Gravity (Gs): 0.77

Fineness Modulus: 0.95

Sieve Diameter (mm)

Weight Retained (g)

Cumulative Weight Retained

(g) Percent

Finer (%)

3/8 inch 9.50 0.00 0.00 100.00

No. 4 4.75 0.00 0.00 100.00

No. 8 2.36 0.00 0.00 100.00

No.16 1.18 0.00 0.00 100.00

No. 30 0.60 0.00 0.00 100.00

No. 50 0.30 0.00 0.00 100.00

No. 100 0.15 475.00 475.00 5.00

No. 200 0.075 25.00 500.00 0.00

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