interim guidelines: the design and use of foamed bitumen treated materials kim jenkins, dave...
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Interim Guidelines:The Design and Use of Foamed
Bitumen Treated Materials
Kim Jenkins, Dave Collings Hechter Theyse, Fenella Long
Road Pavements Forum6 – 7 May 2002
Where are we?
Guideline prepared and reviewed Finalizing document in light of reviews Thank you,
don’t stop now!
Reviewers Elzbieta Sadzik, Theuns Lewis and Enrico Fletcher, Gautrans Les Sampson, Asphalt Academy Piet Myburgh, SABITA Wouter Schreuder and Joe Grobler, VKE Mervyn Henderson and Rassie Otte, PAWC Wolf Reusch, Rumdel Dieter Vietze and Philip Kuun, Blitz Asphalt Jop du Plessis, AA Loudon and Partners Ian van Wijk and Johan Calitz, Africon Nicol van der Walt, Gibb Africa Andre Ungerer, Keeve Steyn Mike White, UWP Engineers
Table of Contents 1. Introduction 2. Selection criteria for identification of suitable
projects 3. Mix design 4. Structural design 5. Construction aspects Appendices
– Test procedure for measuring foamed bitumen characteristics– Laboratory test methods and specimen preparation– Mechanistic-empirical pavement design for foamed bitumen treated
layers
Chapter 2. Selection Criteria
Project Selection Risk Assessment Recycling Process Environmental
Advantages Traffic Delay Advantages Economic Considerations
Chapter 2. Selection Criteria
Chapter 3. Mix Design Important considerations in the mix design process
– Design constraints– Aggregate selection– Binder selection – Fluid considerations – Mixing techniques– Compaction (mod AASHTO)– Curing– Moisture susceptibility– Appropriate surfacings
Aggregate Selection, Magic Triangle
0 20 40 60 80 100
100
80
60
40
20
0 100
80
60
40
20
0
% o
f STO
NE
S%
OF FILLE
R
% OF SAND
FILLER SKELETON
STONESKELETON
SANDSKELETON
High optimum binder content foamed bitumen mix
Ideal foamed mix grading
Suitable foamed mix grading
Chapter 3. Mix Design (cont.) Mix design procedure
– Mix design philosophy– Mix constituents– Sample preparation– Curing– Mechanical testing
Mix Design Philosophy
Improved flexibility
Gre
ater
per
man
ent
def
orm
atio
n r
esis
tan
ce
Unbound material, High quality crushed
stone and aggregate
Moderate quality natural gravel
Low quality natural gravel
Foamed bitumen and emulsion treated
material without cement
Strongly cemented material C2 to C1
Lightly cemented material C4 to C3
Stiff, brittle behaviour
High
High
Intermediate
Intermediate
Low
Low
None
None
Bituminous binder0% 7%
0%
Catalyst
Stren
gth
Cement
5%
Asphalt concrete
Temperature dependent, visco-elastic behaviour
Stress dependent behaviour
Foamed bitumen and emulsion
treated material containing cement
Presumed economically
not viable
Material Classification Interim foamed bitumen treated material classification
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 100 200 300 400 500 600
ITS (kPa)
UC
S (
kPa)
FB4
FB2 FB1
FB3
Chapter 4. Structural Design
Research based on– HVS tests
– Laboratory tests Distress modes
– Effective fatigue
– Permanent deformation resistance
– Balance the distress modes
Chapter 4. Structural Design New pavements
– Catalogues Deep in situ recycling
– Design charts Materials
– FB2, FB3
only
PAVEMENT CLASS AND DESIGN BEARING CAPACITY (80 kN AXLES/LANE)
DATE: January 2002
FoundationROAD CATEGORY
A: Major interurbanfreeways and roads.(95 % approximatedesign reliability)
B: Interurbancollectors and majorrural roads.(90 % approximatedesign reliability)
C: Lightly traffickedrural roads andstrategic roads.(80 % approximatedesign reliability)
D: Light pavementstructures, ruralaccess roads.(50 % approximatedesign reliability)
ES0,01
0,3-1,0x10 4ES0,03
1,0-3,0x10 4ES0,1
3,0-10x10 4ES0,3
0,1-0,3x10 6ES1
0,3-1,0x10 6ES3
1,0-3,0x10 6ES10
3,0-10x10 6ES30
10-30x106ES100
30-100x10 6ES0,003
0,1-0,3x10 4
A0, AP may be recommended as a surfacing measure for improved skid resistance when wet or to reduce water spray. SYMBOL A DENOTES AG, AC, OR AS. SYMBOL S DENOTES S2 OR S4
S
100 FB3
100 G8
S
125 FB3
125 G9
S
125 FB3
125 G8
100 FB3
S
100 FB3
S
150 G7
125 FB3
S
150 G7
S
100 C4
100 FB3
150 FB2
S
150 G7
S
100 C4
100 FB3
S
100 C4
100 FB3
125 FB3
S
150 G6
S
125 C4
125 FB3
30 AC
150 FB3
200 C4*150 FB3
S
200 G6
150 C4
125 FB3
S
175 FB3
30 AC
175 C4175 FB3
175 G6
S
NEW CONSTRUCTION : FOAMED BITUMEN BASE (FB3)
150 G9
G10
150 G7
150 G9
G10
* Minimum thickness for structural capacity. Construct in two lifts increasing thickness for ease of construction, if necessary.
30 AC
125 FB3
150 C4
New Construction, Catalogue
Deep In Situ Reycling, Design Charts
75
100
125
150
175
200
225
250
275
300
0 50 100 150 200 250 300
Support (MPa)
Th
ick
ne
ss
(m
m)
10 000
30 000
100 000
300 000
1 000 000
3 000 000
Category A, FB2
Chapter 5. Construction Aspects General Basic requirements
– Quality of foamed
bitumen– Material being mixes
Before starting– Planning the recycling work– Equipment selection– Logistical planning– Trial sections
Equipment Selection
Working with foamed bitumen– Mixing process
– Moisture content
– Placing and compaction
– Surfacing
Chapter 5. Construction Aspects
Chapter 5. Construction Aspects
Quality control aspects– Thickness
– Quality of foamed bitumen
– Application of stabilising
agents and quality of mixing
– Compaction
– Level and surface shape
Recommendations for Future Work
Mix design– Build up database of shear parameters to move away
from UCS– Replace ITS test for assessing flexibility (beam?)– Compaction specifications, Mod AASHTO versus
BRD, build up experience and establish limits– Laboratory versus field mixing– Curing– Water sensitivity
Recommendations for Future Work
Structural design– FB1, FB4 materials– Wider range of parent materials– Mix behaviour/performance with no active filler– Erodibility, permeability, durability– More advanced material models
Recommendations for Future Work HVS testing