Experimental investigation on mechanical properties of glass fiber reinforced recycled aggregate concrete under uniaxial cyclic compression

In this investigation, glass fiber (GF) was incorporated into recycled concrete to form a new sustainable material (glass fiber reinforced recycled concrete) to solve the shortcomings of easy cracking and high brittleness of recycled concrete. At present, there are few investigations and experiments on the mechanical properties of the material under uniaxial cyclic compression, and there is a lack of prediction of the behavior of the material in a specific mechanical environment. Thus, this investigation focuses on the stress-strain relationship and mechanical properties of glass fiber reinforced recycled concrete (GFRAC) under uniaxial cyclic compression. In order to achieve this goal, the stress and strain of the specimen under cyclic compression were discussed by designing three variables: recycled aggregate replacement rate, glass fiber content, and loading rate. The failure process of GFRAC under cyclic loading was observed and recorded, and the failure mechanism of GFRAC was analyzed in depth from macro to micro levels. The stress-strain curve law of GFRAC under cyclic action is summarized. The plastic strain and stiffness degradation law of recycled glass fiber reinforced concrete were revealed. The hysteretic energy consumption of each cycle is quantified and compared. The results show that, under the influence of GF content and recycled aggregate replacement percentage, GFRAC specimens appeared oblique shear failure, splitting failure and oblique shear & splitting failure under cyclic action. The stress-strain envelope curve of GFRAC under cyclic loading is similar to the monotonic one. Increasing the replacement ratio of aggregates can increase the peak strain of the specimen under cyclic action, and the maximum improvement value can reach 12.62 percent. The addition of GF can improve the ductility of recycled concrete, increase the hysteresis energy consumption, and finally affect the stiffness degradation rate of the specimen. Among them, under the same recycled aggregate replacement rate and the same cycle numbers, the stiffness degradation rate of the specimen with 0.05 % GF content is twice that of the specimen with 0.15 % GF content. This investigation provides a theoretical basis and reference for further research on GFRAC.