Partial replacement of municipal solid waste incineration bottom ash for cement substitution in brick

Abstract

Nowadays in Malaysia, the issue on environment preservation has lead into a new finding on materials that had been disposed to become a good product for construction field. The generation of Municipal Solid Waste Incinerator for example, has become an environmental problem but at the same time, there was some effort to reuse the waste to become good product. In this project, the feasibility of using municipal solid waste bottom ash to replacement of cement to produce brick was determined. The objective of this research are study the engineering properties of brick with the replacement of bottom ash as cement substitution subject to different curing regime. Bottom ash used are brought from incineration plant in Pulau Pangkor. Research have been conducted by partial replacing of 5%, 10% and 15% of raw bottom ash to cement. For this project, the mixes were cured in ambient air and tested at 7, 14 and 28 days. Another few sample were cured in oven and tested at 28 days. Based on the result of this research, the distribution curve for the sand is well graded. The chemical composition of bottom ash and cement had been tested using XRF testing and its mainly consisted of CaO and SiO2. The water to cement ratio were between 0.55 until 0.70 due to the very small of bottom ash particles and their angular surfaces increase the specific surface area of the mix, resulting in a high water demand to satisfy the same workability. The maximum strength of MSWI bottom ash brick is 23.91 MPa with density 2152 kg/m3 and 6.32 % water adsorption using substitution of 5% bottom ash at 28 days with ambient air curing while the minimum strength is 9.27 MPa with density 1979 kg/m3 and 9.30 % water adsorption using substitution of 15% bottom ash at 28 days of oven curing. It is because the brick was over dried by the oven heat and due to over dry occurrence, it decreases the sample weight, and as the density of brick decrease, the compressive strength will also decrease. The failure of the brick pattern is cracking and spalling. It can prove that the replacement of bottom ash can give a good performance as the common brick in the market.