1a1 determination of an effective laying pattern and best block shape for concrete block pavement
DESCRIPTION
highway engineeringTRANSCRIPT
DETERMINATION OF MOST EFFECTIVE CEMENT CONCRETE BLOCK LAYING PATTERN AND
SHAPE FOR A ROAD PAVEMENT BASED ON FIELD PERFORMANCE
By A.A.Senadeera
SupervisorDr. W.A.Mampearachchi
Heavy & Very Heavy Traffic
Research objective
• Determination of most suitable individual block shape for CBP roads.
• Determination of effective laying pattern for CBP roads
Main structural components in CBP
Basket wave
bond
Stack
bond
Stretcher
Bond
Used block shapes & patterns
Herring
bond
Cobble Uni style Key stone
Preparation of sand bed
Paving combinations of shapes and patterns
Section- 0+00-10+00Block- Uni styleLaying angle-0Pattern-Stretcher
Section 30+00-40+00Block- Uni styleLaying angle-90Pattern- Stack
Section- 10+00-20+00Block- Uni styleLaying angle-45Pattern-Stretcher
Section 40+00-50+00Block- Uni styleLaying angle-0Pattern-Herring
Section 20+00-30+00style Block- Uni Laying angle-90Pattern-Stretcher
Section 50+00-60+00Block- Uni styleLaying angle-90Pattern-Basket Wave
Paving combinations of shapesand patterns
Section 60+00-70+00Block- CobbleLaying angle-0Pattern-Stretcher
Section 70+00-80+00Block- CobbleLaying angle-45Pattern-Stretcher
Section 80+00-90+00Block- CobbleLaying angle-90Pattern-Stretcher
Section 90+00-100+00Block- Key stoneLaying angle-90Pattern-Stretcher
Block laying
Deflection shape of the pavement
• Deflection check a. Along the wheel path b. Across the road
• Joint gap measurements
Field tests
4m
4m
10m
1.8m
Selected
Points
Measuring deflection at wheel path
4m
4m
10m
SelectedPoints
0.3m
Measuring deflection across the road
Measuring block joint gaps
Average block joint gap 10 displacements = Initial – Subsequent 1 Measuring Measuring 10 1= A-A, 2= B-B, ----10= J-J = S No of vehicle passes
per day = NNo of vehicles passes per 14 days = 14N Average block joint gap displacements
per 14N vehicle passes = 14NS
Displacements of Block Joint Gaps
Effect of block shape on pavement deflection
Effect of block shape on pavement deflection profile
Effect of block shape on blockdisplacement
Effect of block laying angle ondeflection
Uni Style Cobble
Effect of block laying angle on deflection profile
Effect of block laying angle on block displacement
2nd Week. 4200 Vehi-cle Passes
4th Week. 8400 Vehi-cle Passes
6th Week. 12600 Ve-
hicle Passes
8th Week. 16800 Ve-
hicle Passes
10th Week. 21000 Ve-
hicle Passes
12th Week. 25200 Ve-
hicle Passes
14th Week. 294200 Vehicle Passes
16th Week. 33600 Ve-
hicle Passes
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
1.1
1.2
Angle,90º
Angle,45º
Angle,0º
Vehicle Passes
Blo
ck M
ovem
ent (
mm
)
Effect of block laying pattern on deflection
40
45
50
55
60
65
70
75
80
Defl
ectio
n m
m x
10
-2
E la stic defroma tion 49 80 49 60
S tre tc he r bond S tra c k bond Herring bond B a sket Wa ve
Effect of block laying pattern on deflection profile
Effect of block laying pattern on block displacement
2nd Week. 4200 Ve-
hicle Passes
4th Week. 8400 Ve-
hicle Passes
6th Week. 12600 Ve-
hicle Passes
8th Week. 16800 Ve-
hicle Passes
10th Week. 21000 Ve-
hicle Passes
12th Week. 25200 Ve-
hicle Passes
14th Week. 294200 Vehicle Passes
16th Week. 33600 Ve-
hicle Passes
00.10.20.30.40.50.60.70.80.9
11.11.21.3
Angle 90o
Strack bond
Herring bond
Basket wave bond
Vehicle Passes
Bloc
k M
ovm
ent (
mm
)
Summery of the analysis
Variable Performance
Deflection Deflection profile
Joint gape variation
Selection
Block shape
Uni style Uni styleCobble
Keystone
Laying angle
Angle 00 Angle 00
Angle 450
Angle 900 Angle 900
Block laying
pattern
Stretcher bond Stretcher bond
Stack bondBasket wave
Herring bond Herring bond
Note: Best performance indicate as
Recommendations
• The most effective block shape for cement concrete block laying is Uni style block shape.
• The recommended block pattern are Stretcher and Herring block pattern.
• The recommended block laying angles are zero or 90 degree.
End
Thank you