Shear behavior of novel hybrid composite beams made of self-consolidating concrete and engineered cementitious composites

Shear performances of hybrid composite beams, a combination of two different layers of self-consolidating concrete (SCC) and engineered cementitious composites (ECC) were investigated. Composite beams were made with two different ECC to SCC depth ratios. Full depth beams, consisting of a single layer of either SCC or ECC, were also made and tested to compare their performance with respect to that of hybrid composite beams. Both full depth and composite beams were made with and without shear reinforcement. The performance of shear beams was evaluated in terms of load-deflection response, first diagonal crack load, post-cracking shear resistance, energy absorption, and ductility index. Compared to the full depth SCC and full depth ECC beams, non-shear reinforced hybrid composite beams showed higher ductility and energy absorption capacity which indicates suitability of hybrid composite to be used in earthquake resisting elements. Hybrid composite beams also showed higher number of cracks with lower crack width. Code based equations and other design specifications were found to be conservative in predicting shear strength of hybrid composite beams. However, the theoretical capacity was found to be higher than that of experimental shear resistance in case of full depth ECC beams.