A novel cement-based auxetic foam composite: Experimental study

Auxetic foam materials contract (expand) laterally under uniaxial compressive (tensile) load. Due to superior characteristics of auxetic foam, e.g., shear resistance and in-plane indentation resistance, studies of auxetic foam composites have been increasing in recent years. In this paper, a novel cement-based auxetic foam composite is designed, fabricated and experimentally investigated. The influence of foam hole density, mass fraction and age on the flexural and compressive strength of the composite is analyzed. The failure modes and crack development of the specimen are examined. It is found that the flexural and compressive strength of composite are improved at the curing age of 7 and 14 days, and reduced at the curing age of 28 days with the incorporation of auxetic foam. And the flexural compression ratio of the composite is greater than that of matrix material. The integrity of the specimen is preserved during the compression failure process of cement-based auxetic foam composites. It is indicated that the incorporation of auxetic foam improves the toughness and deformation behavior of composites.