The production of lightweight aggregates using ordinary portland cement

Abstract

The research study covers the production of lightweight aggregates using Ordinary Portland cement (OPC) without involved any heat treatment. The main aim of this research was to produce lightweight aggregate as artificial aggregate which can be used to replace natural aggregate such as granite in concrete. OPC, liquid Alkylbenzenesulfonates and rice husk were the main raw materials were used in this study in order to produce lightweight aggregate. The production processes of lightweight aggregate from OPC involved grinding, mixing of raw materials, agglomeration and curing process for binding of the particles. This study involved on the physical, mechanical and chemical properties of raw materials such as OPC, liquid Alkylbenzenesulfonates and rice husk. The effect of using liquid Alkylbenzenesulfonates and rice husk in lightweight aggregate on bulk density, percentage of water absorption, pore and texture, specific gravity and also microstructure of lightweight aggregates were examined. The raw samples were characterized by X-ray fluorescence (XRF) and the porosity of aggregate was examined by scanning electron microscope (SEM). XRF result showed that rice husk of highest contained of SiO2 equal to 56.3%. Lightweight aggregates LWARH produced from rice husk have low density equal to 761 kg/m3 indirectly will reduce the self weight of concrete but the strength only 9.80 MPa at 28 days. The best lightweight aggregates LWA obtained from this study consisted of OPC, 15% of liquid Alkylbenzenesulfonates, 15% of water and potential for further research study. Successfully test result obtained showed the lightweight aggregate LWA had aggregate bulk density of 1215 kg/m3 for coarse aggregates. The 24 hours water absorption for aggregate LWA was 8.48% and contained 0.001973mm2 area of porosity. Lightweight concrete LWAC was produced using the lightweight aggregates LWA. The compressive strength at the average of 28 days compressive strength was recorded as 20.39 MPa (20.39 N/mm2). This result successfully achieved the required compressive strength of lightweight concrete is 17 MPa at 28 days by ASTM C330 (2009). However, the bulk density equal to 2080 kg/m3 is not categorized as lightweight aggregate concrete by BS EN 206-1 (2000) because the bulk density is more than 2000 kg/m3 but only 4% higher.