Experimental Investigation of LTE in Relation to Crack Width of Non-Dowelled Joints in Concrete Pavements

Dowel bar insertion and aggregate interlocking are the major load transfer mechanisms in rigid pavement joints. Aggregate interlocking is much efficient method for thin .concrete pavements. The effectiveness of aggregate interlocking mechanism depends on strength of concrete, strength of aggregate, maximum aggregate size, friction of cracked surfaces, slab thickness and crack width (CW). Some of these factors vary with the pavement life and directly affect the Load Transfer Efficiency (LTE). This paper describes an experimental investigation to obtain the relationship between CW and LTEin a rigid pavement joint. A 150mm thick concrete pavement with grade 25 concrete with 20 mm coarse aggregate was used to obtain the LTE at cracked joint. Standard single axel single wheel load of 40 kN was used to simulate the tire load. Deflection due to wheel load at either side of the joint was measured for different CWs. It was observed that LTE decreases nonlinearly with the increase of CWoFor the slab tested, LTE of 60% was obtained for CW of 2.3 mm. The results obtained from the experimental investigation can be used to design the joint spacing in nondowelled rigid pavements