Flexural performance of concrete beams containing engineered cementitious composites

Abstract Engineered Cementitious Composites (ECC) considers a type of ultra-ductile cementitious composites with fiber reinforcement. It is developed for applications for economic purpose in the construction industry. ECC characterizes by strain hardening and multiple cracking. This paper experimentally investigates the performance of ECC concrete beams reinforced with conventional reinforcement bars. Advanced Polyvinyl Alcohol Engineered Cementitious Composite (PVA-ECC) fibers were selected in this purpose. Twelve RC beams were poured and tested to study flexure behavior under four-point loading test. Two different longitudinal reinforcement percentages, variable volume ratios of (PVA) and polypropylene fibers (PP) were used. optimizing the usage of PVA material trails to put it in the lower layer of the section at point of maximum tension with variable thicknesses was conducted. Initial flexure cracking load, ultimate load, the ductility and the load-to-deflection relationship at various stages of loading were evaluated. Experimental outcomes revealed that the enhancement in maximum capacity is more significant in the case of using PVA rather than PP. The maximum load increases by 20% and 34% for 1.0% and 2.0% of PVA contents in total section respectively. The relative ductility factor increases by 30% and 45% for 1.0% and 2.0% of PVA content. Results also depicted that a reasonable considerable increasing in the load capacity when used limited layer thickness of PVA concrete. Nonlinear Finite Element Analysis (NLFEA) was conducted for the purpose of simulating the behavior of experimentally tested beams, regarding crack behavior and load-deflection response. Reasonable agreement was achieved between the experimental results and NLFEA results.