Strength criterion for ecological light porous concrete under multiaxial stress

• Experiments of four kinds of ecological light porous concrete (ELPC) were carried out to study the mechanical properties.
• A model of five-parameter strength criterion of ELPC is established according to the unified strength theory.
• The general formula describing the tensile and compressive meridians of ELPC is obtained.
• The expression of meridians in two-dimension is obtained.
• The relationship between force and displacement of the fundamental element is studied both numerically and experimentally.

With characteristics such as light weight, high strength, energy saving and good seismic performance, the multi-ribbed composite wall structure has been developed in recent years at some areas in China. Its fundamental components are usually collectively referred to as ecological light porous concrete (ELPC), which includes ecological lightweight aerated concrete block, ecological foam concrete block, ecological EPS lightweight concrete block and eco-plant fiber cement-based materials. The purpose of this paper is to conduct a comprehensive study on the mechanical properties and strength criterion under multiaxial stress for ELPC. In the present paper, experiments of four kinds of ELPC were carried out to study the mechanical properties. Many common features are found such as low strength, elastic and brittle properties. Considering the common features, a model of five-parameter strength criterion of ELPC is established according to the unified strength theory. Due to taking the intermediate principal stress σ2σ2 into account, this model is more realistic. The general formula describing the tensile and compressive meridians of ELPC is obtained. This general formula can be degraded to find the expression of meridians in two-dimension. Based on the multiaxial failure criterion of ELPC given by this study, the relationship between the force and displacement of the fundamental element for a masonry in-filled frame is studied both numerically and experimentally. They are reasonably consistent. The present paper broadens the research field for light porous materials. The five-parameter strength criterion and its special forms in two-dimension would be extremely useful for researchers and engineers interested in ELPC.