Research on the expansion behavior of containing silica recycled materials after high temperature sintering in cement matrix

This research discusses the potential ASR problem for the recycled aggregates of sintered by high temperature procedure (RAs). Using ASTM methods assess the ASR reactivity of RAs, analyze pessimum effects, and discuss the inhibiting effect for pozzolanic material on ASR problem of RAs. Results: show that TFT glasses, ceramic sands and cast sands are ASR reactive aggregates. The pessimum cement alkali equivalent content of TFT glasses and ceramic sands are 1.5~2.0% and 1.25~2.0%, respectively, and cast sands is not observed this effect. Ceramic sands and cast sands have the pessimum aggregate sizes of 1.18~2.36 and 0.15~0.30 mm, and TFT glasses have not this effect. TFT glasses have not the pessimum replaced proportion, but ceramic sands and cast sands have the pessimum replaced proportions of 50% and 30%. Using low-alkali cement can inhibit the ASR expansion of RAs. The harmful ASR expansion of RAs can be inhibited effectively when using fly ash replaces cement of 15%, 15% and 20% by weight, or using the blast furnace slag of 60%, 40%) and 60% by weight, respectively.