Use of demolition waste to reduce cement usage in cement composite

Abstract

As a developing country, construction is one of the main incomes producing in Malaysia. Huge amount of demolition waste were produced from these activities. In Malaysia, the construction waste has cause a significant impact on the environmental and also increasing the concern of the society and the waste generation is found to be in an increasing trend. These demolition wastes are disposed illegally or disposed at landfill. This study is to examine the suitability of demolition waste produced used to replace cement in concrete composition. Features such as specific gravity, and elemental composition were studied. The amount of demolition waste that is used in concrete mix proportion is 10 %, 20 % and 30 % and compared with 0 % as control. The performance of concrete samples was monitored through their compressive strength at 7, 14 and 28 days. Based on the result of this study, the suitable percentage of demolition waste use in mix proportion is less than 10 %. The result for 10 % is 33.2 MPa. The higher percentage demolition waste in mix proportion reduces the strength of concrete. These due to binder material content in cement and rubble remains were different terms of quantity. Binder will react with water for concrete hardness. Characteristics of this binder material such as Calcium Oxide, CaO influence concrete strength. Binder material shortages in demolition waste disturb hydration process and influence concrete strength.