Effects of cenosphere on the mechanical properties of cement-based composites

Cenosphere is an industrial waste residue used as lightweight aggregate in cement-based composites. In this work, we investigated the influences of cenosphere on the properties and applicability of cementbased composites. The compressive and flexural strength, bending toughness, tensile ductility, and shrinkage of the composites were measured. Meanwhile, the environmental and economic benefits of cenosphere were analyzed. Our results showed that cenosphere-added lightweight cement-based composites exhibited a density of 1477.52-1734.23 kg/m(3), compressive strength of 63.94-70.69 MPa, and flexural strength of 9.50-14.71 MPa, depending on the cenosphere content. The calculated fracture energy of the matrix notably dropped with increasing cenosphere content due to the weak interface transition zone between the aggregate and cement paste. Moreover, the incorporation of cenosphere had a negative effect on the tensile strain capacity and tensile strength of composites. The high bridging stress of the fibers ensured the tensile ductility and bending properties of the cement-based composites. Due to internal curing effect of cenosphere, the shrinkage of lightweight toughness cement-based composites was effectively reduced with increasing cenosphere content. Compared with the control group, the embodied energy of the cement-based composites containing 30% cenosphere was reduced from 10.12 to 7.20 GJ/m(3), while the global warming intensity was reduced by 37.85%. Therefore, developing ecofriendly cement-based composites with cenosphere is viable approach to mitigate the environmental costs of construction. (C) 2020 Elsevier Ltd. All rights reserved.