Cyclic Stress-Strain Model for Air-Entrained Recycled Aggregate Concrete after Freezing-and-Thawing Cycles

摘要

To study the compressive stress-strain behavior of air-entrained recycled aggregate concrete (ARAC) after freezing-and-thawing cycles (FTCs), 72 prisms with different replacement ratios of recycled coarse aggregate (RCA) and varying numbers of FTCs were tested under monotonic compression loading and cyclic compression loading. The experimental results show that increasing the RCA replacement ratio deteriorated the frost resistance of ARAC. An axial stress-strain modelfor ARAC subjected to cyclic compressive loading after FTCs was presented based on the test results. The proposed stress-strain model consists of three main components: a monotonic stress-strain model to describe the envelope curve, a polynomial expression considering the plastic strain and unloading modulus at zero stress for the unloading path, and a linear expression for the reloading path. The model was further validated by comparing the predictions with the experimental stress-strain curves.