Sustainable reuse of household ceramic wastes as a substitute of cement and natural sand in construction materials: Mechanical, transport, and microstructural properties

The feasibility of utilizing recycled household ceramic wastes as partial substitutions of cement and natural sand in concrete was investigated. The broken household ceramics in Jingdezhen were crushed and ground to obtain ceramic powder and aggregates. The effects of ceramic replacements on strengths, durability indexes, and microstructure characteristics of cement mortars were experimentally studied. Mechanical tests (compressive/flexural strength), durability tests (resistance to mass transports), and microstructure examinations (pore structure/morphology) were conducted. Results indicate that: (1) the integration of 20% ceramic powder raises the strengths by 5 ∼ 9% with sufficient curing, and consistently decreases the gas permeability by 16%, as well as the capillary sorptivity by 44%, attributing to the filling and blocking effects of micro-ceramic particles; (2) the presence of 20 ∼ 40% fine ceramic aggregate increases the strengths by 21 ∼ 35% and also reduces the transport properties by 21 ∼ 67%, relating to the pozzolanic reaction on the ceramic aggregate surface, but these benefits tend to diminish as the proportion of ceramic substitution increases further; (3) the reasonable incorporation of household ceramic wastes, as cement and fine aggregate replacements in concrete manufacturing, can be adopted to produce cement mortars with comparable mechanical and durability performances along with waste management.