Flexural performance of steel-reinforced engineered cementitious composites with different reinforcing ratios and steel types

摘要

Reinforced engineered cementitious composites (ECC) flexural members fail either after a dominant crack forms (i.e., crack localization) or after gradual strain hardening of reinforcing steel. These two failure paths represent distinct ductility ranges and load reduction mechanisms that have not been fully characterized. This study experimentally investigates the two failure paths of flexural members with different reinforcing ratios (0.53%-2.10%), two types of reinforcing steel (A615 Grade 60 and A1035 Grade 100), and under monotonic and cyclic loading conditions. A total of twelve simply-supported beams are tested including two conventional concrete beams for baseline comparisons. Based on the experimental results, a recently-developed flexural strength prediction method is validated. Results show that (1) the two failure paths are affected by the reinforcing ratio and steel type, (2) ECC sustains a maximum compressive strain that is larger than 1.0% before crushing, (3) ECC effectively restrains crack width opening for flexural members using high strength (Grade 100) steel reinforcement, and (4) a recently proposed flexural strength prediction method is able to predict the experimentally observed flexural strength of the beams with an error less than 5%. (C) 2019 Elsevier Ltd. All rights reserved.