Possible causes Description How to Measure Possible causes Description

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b. How to Measure

Longitudinal and transverse cracks are measured in linear meter. The length and severity of each crack should be recorded after identification. If the crack does not have the same severity level along its entire length, each portion of the crack having a different severity level should be recorded separately. If a bump or sag occurs at a crack it is also recorded as a distortion.

c. Possible causes

i. A poorly constructed paving lane joint. ii. Shrinkage of the surface due to low temperatures or hardening of the asphalt and daily temperatures cycling. iii. A reflective crack caused by joints and cracks beneath the surface course. iv. Decreased support or thickness near the edge of the pavement GTC, 1998.

2.3.1.4 Edge Cracking

a. Description

Edge cracking is crack in the side is parallel to the edge of the pavement and away from a distance ranging between 0.3-0.5 meters from the edge, and extends these cracks longitudinal and transverse direction and branching towards the shoulders. And increasing the cracks as a result of side-load traffic is classified as the area enclosed between the part and the edge of pavement as volatile if there has been a break. Edge cracking is shown in Figure 2.6 David, 2006. 21 Figure 2.6 Edge Cracking GTC, 1998

b. Severity levels

Low level of intensity L: It is a shallow surface cracks do not cause breaks and loss of materials on the pavement. Medium level of intensity M: Moderate cracks are classified when they contain break and loss of materials in the length of up to 10 of the length of the paving of the area affected. Higher level of intensity H: It is a deep and many cracks and contains break and loss of materials in the length of more than 10 of the length of the paving of the area affected. c. How to Measure Surface cracks measured longitudinal profiles for each level of severity alone. Measured by the area affected by the defect length of the affected area multiplied by one meter, and the defect density is calculated by dividing the area affected by the total area of the section scanned multiplied by one hundred.

d. Possible causes

Side show cracks due to poor layers of the foundation and bedrock near the edge of pavement GTC, 1998.

2.3.1.5 Reflection Cracking

a. Description

These cracks appear only on the surfaces of asphalt that would be implemented cement concrete slabs, cracks and does not include the reflectivity of the base layers. See Figure 2.7 These cracks arise as a result of traffic generated by heat and moisture between the concrete slab and the bottom surface of the concrete asphalt, in regard to this defect earlier pregnancy, however, the traffic loads can cause the asphalt to break the surface near the cracks which destroy. If you know 22 the dimensions of concrete slab on the bottom, it helps to know this defect ASTM D6433, 1999 David, 2006. Figure 2.7 Reflection Cracking GTC, 1998

b. Severity levels