The effect of a complex pozzolanic additive consisting of milled glass and metakaolin on the degradation of a cementitious composite with ground waste glass caused by alkali-silica reaction

Abstract

This paper investigates the effect of partial replacement of cement by milled glass (MS), metakaolin (MK), and their mixture and partial replacement of sand by crushed glass (TS) on the physical and mechanical properties of a cementitious composite, as well as on the resistance of the composite to degradation caused by alkali-silica reaction (ASR). After 28 and 56 days of curing, the highest improvement in the mechanical properties was observed in the batches of specimens with the MS, MK and their mixture. The physical and mechanical properties of specimens with partially replaced sand to TS also deteriorated the least (the lowest expansion 0.02 %) with the application of the MS and MK mixture after 56 days of exposure to alkaline attack. XRD and microstructural analyses have shown that the reduction in expansion is due to the higher content of hydration products, as well as to the denser contact zone between the aggregate and the cementitious matrix.