Research On Architectural Concrete Prepared With Recycled Clay Brick Of Construction And Demolition Wastes

With the rapid progress of urbanization, the construction and demolition(C&D) wastes continuously increase. However, confronting with more than 1.5 billion's generating per year, the rate of reusing is even less than 5%in China. Regarding to the national conditions, among all C&D waste. the clay brick occupies a proportion of about 40%-60%. Besides, the quality of reused products made by recycled clay brick in general is low because of high porosity, low strength, high water absorption, etc., leading the marketing competitiveness relatively reduced. Thus, it is pretty urgent to develop new technologies that are aiming to enhance the added value of recycled clay bricks.Whilst, the rapidly increased quantity of auto mobiles generates a series of serious problems including large emission of exhaust that is mainly contained by NOx. It is in general reckoned as the main causing problem of haze. Nevertheless, this dissertation will put forward an innovative approach to combine traditional photo-catalysis of P25 and cement base materials and effectively reduce the NOx.The entire research of this dissertation is mainly contained by four aspects. Above of all, it is to design a kind of architectural concrete that contains both surface layer and base layer. The surface layer contains some compound photo-catalysts made by TiO2 carried by clay bricks; whilst the base layer is made by concrete. Then, it is to research the NOx removal led by the surface layer and the optimal mix proportion of the surface layer. Next, it is to test the mechanical and durability performance of the surface layer that is prepared with the optimal mix proportion. At length, it is to compare two carriers of clay brick and natural zeolite and their respective performance on carrying TiO2 and removing NOx.Two main research results are achieved. On one hand, recycled motor prepared by recycled clay brick is of weaker peace-ability. Though its relative strength compared with natural sands is about 40% to 80%, it is still capable to satisfy the requirement of common construction mortar. As to the mortar prepared by the natural zeolite, it has low water absorption, tougher aggregates, and higher hardness, leading its relative strength is about 50% to 80%. On the other hand, the architectural concrete prepared by the compound photo-catalysts is of good photo-catalytic performance which is mainly embodied by the NOx removal. Whilst the most optimal photo-catalytic effect is observed when the mix proportion between photo-catalysis and glass cullet is 1:1 and substitution rate of clay brick upon cement is 50% by weight. However, the performance of compound photo-catalysis prepared by natural zeolite is relatively worse than clay brick.Overall, basing upon these search, the recycled clay bricks are capable to prepare surface layer that is of relative good photo-catalytic performance. Besides, it will greatly enhance the added value of recycled clay bricks.