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