Experimental investigation of dowel action

The dowel provided by steel rebars in reinforced concrete has been a research topic since the early 1940’s when its use started to spread for pavement slabs and airport runway construction. This experimental study focused on investigation of dowel action without stirrups. To induce the dowel action, 3 blocks are casted separately with 2 shear planes but with a single dowel bar. There are total of four specimens casted and subjected to cyclic loading as well as monotonic loading. The displacement controlled cyclic loading test is carried out on specimens with 2 different cover to rebar diameter ratio. The central block is where displacement is induced, and study of dowel action is carried out on the lateral blocks. The LVDT transducers are placed at central block and at dowel bars on lateral blocks to measure the displacements. The results of the cyclic and monotonic tests of individual specimens are studied to understand the behaviour as well as compared with the lab observations during experiment and presented. As the investigation is aimed towards the stirrup less specimens, the concrete cover plays an important role and the same is observed from the results. The ideal behaviour of failure of cover concrete from loading forefront towards the embedment. The trend in overall behaviour is found to be the yielding of steel during initial small deformations as concrete is intact, then gradual damage of cover concrete with increase in deformation and ultimately failure according to the further development of damage of cover towards the embedded direction.