waste glass

pervious concrete

furnace slag

autogenous shrinkage

alkali-activated slag

blast furnace slag

recycled aggregate

water absorption

slag powder

Construction and Building Materials

• Conducted experiments to develop ultra-lightweight cement (ULCC) that replaced alkali activated slag cement (AASC) with 50%, 60%, and 70% large-capacity cenospheres. • In addition to the substitution rate of cenosphere, particle size also affects compressive strength, dry density, moisture absorption and thermal conductivity properties. • The smaller the particle size, the higher the strength, the lower the dry density and the lower the thermal conductivity, but the water-absorption rate increases. • ULCC with 70% replacement of cenosphere floated in water. In this study, the properties of alkali-activated slag cement (AASC), in which 50, 60, and 70% cenospheres were replaced, were tested and flotation tests were performed by making bricks. Three different cenosphere sizes were used in the experiment. As the cenosphere replacement rate increased, the compressive strength, density, and thermal conductivity values decreased and the water-absorption rate increased. The smaller the cenosphere particle size, the lower was the thermal conductivity and density and the higher was the absorption and compressive strength. Furthermore, the bricks made of 70% cenosphere-substituted mixture floated on the water surface regardless of the size of the cenosphere particles. In AASC with a cenosphere substitution rate exceeding 50%, the size of cenosphere particles greatly affected the physical and mechanical properties. The 70% cenosphere replacement sample was found to be applicable as a floating structural member for marine and freshwater applications.

Characteristics of alkali-activated slag cement-based ultra-lightweight concrete with high-volume cenosphere