废弃玻璃粉在混凝土中的应用机理及ASR风险

废弃材料广泛应用于土木工程领域,废弃玻璃粉用作混凝土辅助胶凝材料符合我国建材的可持续发展要求。在大量文献调研的基础上,分析废弃玻璃在混凝土中应用的可行性。结果表明,玻璃在复合胶凝材料水化硬化过程中不仅具有一些特殊的作用机理,还存在ASR风险。由于含有大量的无定性二氧化硅,玻璃用作骨料时容易引发碱-骨料反应,但磨细成粉料可用作活性辅助胶凝材料。因此,本文提出将废弃玻璃粉磨成粉体材料用作混凝土辅助胶凝材料,并探讨废弃玻璃粉在复合胶凝材料水化硬化过程中的作用机理及ASR风险。将废弃玻璃磨细成粉料,既可以解决玻璃骨料的碱-骨料反应问题,还能发挥其火山灰作用,改善混凝土的性能。

Mechanism of Waste Glass Powder in Concrete and Its ASR Risk

Waste materials are widely used in civil engineering, and waste glass powder can be used as a supplementary cementitious material, which accords with the requirement of sustainable development of building materials. On the basis of a large number of literatures, the feasibility of adding waste glass in concrete is researched. Results show that, as a new potential auxiliary cementitious material, glass powder not only has some special effect on the hydration and hardening of composite cementitious material, but aslo has risk of alkali-silica reaction (ASR). As there is plenty of amorphous silicon dioxide in glass, alkali-aggregate reaction easily takes place, but glass powder can be used as active supplementary cementitious material. Furthermore, we present that waste glass which is grinded into powder can be used as auxiliary cementitious material and discuss the effect of glass powder on the hydration and hardening of composite cementitious material and its ASR risk. Grinding waste glass into powder not only reduces risk of alkali-aggregate reaction, but also promotes fly ash action of glass and improves performances of concrete.