Shear strength of steel-concrete-steel sandwich deep beams: A simplified approach

Steel-concrete-steel composite structure comprises a concrete core sandwiched between the outer steel plates. It combines the advantages of both steel and reinforced concrete structures. In thick steel-concrete-steel structural members, the shear performance becomes rather critical. Experimental works have been carried out to study the failure mode and shear strength of steel-concrete-steel deep beams, and an analytical model has been proposed. In this article, parametric studies are carried out on the original analytical model to discuss the influence of each geometric and material variable on the shear strength, and a simplified strength predicting method is developed. Different shear failure modes, identified as "top+bottom triangular area damage" or "bottom triangular area damage+horizontal cracking," can be predicted with the method. The simplified approach shows good correlation with the experimental results, regarding to shear resisting pattern and failure modes. Through the simplified formulas, the upper and lower bounds of the shear resistance are obtained. The requirement on stud spacing to maintain full composite behavior in the top and bottom triangular areas and the requirement on concrete strength are proposed.