Effect of silica fume and waste marble powder on the mechanical and durability properties of cellular concrete

Waste marble powder (WMP) is industrial waste characterized by serious environmental pollution and a low recycling rate. To determine if WMP can be used for partial cement replacement in concrete production, more in-depth and comprehensive research is needed. Moreover, cellular concrete has deficient strength, durability and environmental friendliness, which could be improved by incorporating both silica fume (SF) and WMP. Hence, this study investigated the effects of SF (0%, 2.5%, 5% and 10%) and WMP (0%, 5%, 10%, 15% and 20%) on the mechanical and durability properties of cellular concrete. The slump, density, water absorption and mechanical properties of cellular concrete were discussed. The resistance of cellular concrete containing SF and WMP to MgSO4 and H2SO4 attack was evaluated by changes in compressive strength, splitting tensile strength, mass and microstructure. The cellular concrete with 10% SF and 5-20% WMP exhibited the optimal mechanical and durability properties. After H2SO4 attack, this concrete exhibited significantly higher mechanical properties than the control group and substantially less concrete deterioration and mass (0.20-1.49%), compressive strength (27.40-40.20%) and splitting tensile strength (37.26-46.04%) losses. Moreover, scanning electron microscopy (SEM) images showed that specimens containing SF and WMP (especially SF10 and SF10M5) exhibited better resistance to MgSO4 and H2SO4 attack. Overall, appropriate SF and WMP replacements of cement significantly improved the mechanical and durability properties of cellular concrete, especially after sulfate acid attack. (C) 2019 Elsevier Ltd. All rights reserved.