Experimental and finite element analysis of hybrid fiber reinforced concrete two-way slabs at ultimate limit state

Concrete is a brittle material that is weak in tension and is prone to internal microcracking. With the constant demand for improvement in concrete’s durability and mechanical proprieties, the use of fiber reinforcements has shown promising results. The findings of this paper are based on test results on hybrid fiber reinforced concrete (HFRC) samples of simply supported two-way slabs, produced with a selected volumetric proportion of steel fiber (SF) and polypropylene fibers (PPF). A total of twenty-one specimens were fabricated. Concrete slab specimens were tested under flexural loading and their response in terms of strain, deflection, first crack, and ultimate failure loading was determined. The dosage of SF in concrete ranged from 0.7 to 1.0%, whereas 0.1–0.9% PPF was used by volume of concrete. It was found that a combination of 0.9% SF and 0.1% PPF gave favorable results for loading capacity, ductility, and cracks. A Finite Element Analysis (FEA) of the proposed HFRC two-way slabs was also performed via ABAQUS. The outputs from numerical modeling showed a close agreement with the experimental results. Using the selected FEA model, an extensive parametric study was also done to examine the effect of various parameters including longitudinal reinforcement ratio, compressive strength of concrete, and the concrete cover of specimens. The proposed FEA model presented a close agreement with the experimental outcomes.