Behavior of Continuous Composite Beams of Fiber Concrete Slab and Steel Beam

Abstract

This work deals with the behavior of structural continuous composite steel-concrete beams. In the present study, an experimental work has been done by casting and testing two simply supported composite beams, (with and without steel fibers) and two continuous composite beams (with and without steel fibers) up to failure to examine its behavior under static loads. The steel fiber volumetric percentage was 0.5 %. Also, cubic and cylindrical specimens have been cast and tested to determine the concrete compressive and tensile strengths. A high range water reducing admixture (HRWRA) and silica fume (SF) have been used as additives to enhance the fiber concrete properties. So, several trial mixes have been cast and tested to determine the better ratio of these mixtures with respect to the concrete mechanical properties. In the present research, available experimental tests on composite steel-concrete beams are theoretically analyzed using the finite element technique based on one dimensional model. The adopted one dimensional model is able to simulate the overall flexural behavior of composite beams, this covers; load-deflection behavior, longitudinal slip at the steel-concrete interface, and distribution of shear studs. Comparison between the experimental results (for deflection and loads of failure) with those obtained from the proposed finite element model indicates acceptable agreement. It is found that the difference in deflection value between experimental results and theoretical results for no-fiber simply supported composite beam reach 11%, and at 0.5 % steel fibers percentage reach 13 %. While in the continuous composite beam for plain concrete the difference in results may be 9 %, and at 0.5 % steel fibers percentage may be 12 %.