Experimental investigation on triaxial mechanical properties of coral coarse aggregate-sea sand seawater concrete

Abstract

The application of coral coarse aggregate-sea sand seawater concrete (CSSC) in offshore engineering construction is one of the effective measures to realize the rational allocation of resources and alleviate the shortage of resources. In addition, considering that concrete structures in coastal areas may be under triaxial stress, it is necessary to study the triaxial mechanical properties of CSSC. To study the triaxial mechanical properties of CSSC, the effects of aggregate combination and lateral confining pressure on the failure mode, stress-strain curve, yield stress and yield strain of specimens were studied by conventional triaxial tests. The results show that CSSC is more susceptible to the influence of lateral confining pressure. Under the lateral confining pressure of 6 MPa, the crack form transformation and plastic flow appear on the surface of the specimen. Under the lateral confining pressure of 12 MPa, the stress-strain curve appears "stress platform", while the gravel coarse aggregate concrete shows the above changes under the lateral confining pressure of 15 MPa and 24 MPa, respectively. When the lateral confining pressure reaches 15 MPa, the stress-strain curve of CSSC presents a bilinear shape with a second linear branch. With the increase of confining pressure, the damage development rate gradually decreases, and the yield stress and yield strain gradually increase. Finally, the triaxial compression constitutive model of CSSC is established, which can effectively predict the bilinear behavior of the CSSC curve.