Study on the Preparation of New Wall Materials from Urban Construction Waste

Abstract

Graphene oxide (GO) has considerable application value in the concrete field, but its poor dispersion performance in cement restricts its adhibition. In this study, GO and water reducer composites (S-GO) obtained by ultrasonic dispersion treatment were used to promote the dispersion property in cement, meanwhile, the effects of water reducer species and GO dosage on mechanical properties and microstructure of recycled wall materials were investigated. By comparing the effects of four different water reducers, the greatest was polycarboxylate superplasticizer (PCs). When the optimal dosage of GO composite (PGO) was 0.06%wt, the compressive and flexural strength of the concrete specimens after curing for 28 days increased by 30% and 26% compared with the control sample. SEM results show that the hydration products of cement are evenly distributed and arranged in an orderly manner, which were the critical factors for improving mechanical property of cement. The study provided a reliable method for enhance the mechanical performance of recycled wall materials. Introduction With the development of China's economy, science and technology, the construction industry is also booming. A large amount of construction waste is generated every year, which accumulates into a mountain and occupies a large amount of land resources. Moreover, landfills often cause serious hazards and affect the normal life of citizens every year. It has become an urgent problem to break up and recycle construction waste. Lv S, professor of Shaanxi University of Science & Technology, conducted research on the template effect of GO on the formation of cement hydration crystals [1,2] . On the basis of this research, this experiment prepared high-performance wall materials by adding self-made GO composite materials into recycled aggregate of construction waste, and studied the influence of GO composite materials on concrete hydration products, microstructure and properties, laying a theoretical foundation for the establishment of structural model of recycled wall materials [3,4] .