Study on Strength and Volume Stability of Coral Mortar

The continuous construction of islands and reefs requires a large amount of traditional building materials, such as cement, sand, and aggregate. Rational utilization of local coral reef sand is conducive to reduce the environmental loading, construction costs and project duration. A lot of research has been carried out about the use of coral aggregate in concrete, such as mixture design, mechanical properties and durability. As we known, the workability and volume stability are extremely important parameters to study the mechanical properties, even the durability of coral concrete. In this study, the flowability and length change of coral mortar are investigated firstly. Since coral sand has large porosity and high water absorption, the coral sand is used with the same volume of standard sand. Furthermore, 15% coral sand powder (CSP) and 15% limestone powder (LSP) is used to replace cement partially in order to reduce the use of cement, respectively. The study of length change of coral mortar includes the determination of wet expansion and drying shrinkage.