Studying the effect of embedded length strength of concrete and diameter of anchor on shear performance between old and new concrete

Abstract This article illustrates the specifications required to accurately design, specify, and install embedded anchor bolts between old and new concrete composite specimens for concrete repair or reinforcing of collapse concrete a research hotspot. The concrete slabs are facing a major challenge with deterioration, especially for reinforcement corrosion caused mainly by severe cycles of various chemical attacks. In this research, the impact of using contact plates between composite specimens was investigated by testing grouped specimens, thereby the models were divided into two groups, which tested under static load. The findings of a series of tests conducted to evaluate the structural behavior of shear connections (by pushout test) by including many parameters; the diameter (8, 12 and 16 mm), bounding between different compressive strength should be changed [normal concert (NC) mixes , ultra-high performance fiber concrete (UHPFC), and self-compacting mortar (SCM)]. Also, the embedded length of bolts was varied from 70, 130, to 190 mm. These parameters were studied individually in two groups. The first group was without contact plate and the second group was with contact plate. Experimental findings were obtained and reported, including the failure modes, maximum resistance, slippage capacity, and load–slip characteristic responses of the connections. Based on the obtained data, a relationship between the studied parameters was investigated. Experimental findings showed that the ultimate strength of rough surface specimens (without contact plate) was about 31% greater than that of smooth surface specimens (with contact plate), and obviously, all pushout specimens failed due to stud shank failure.