Utilization of Rice Straw Wastes as Aggregate in Lightweight Concrete Block Production by Using Cold Press Technique

Abstract

A massive rice straw waste was collected annually after the harvesting period. To reduce the air pollution/PM 2.5 during the burning season and to utilize those straw wastes, the development of rice straw based-lightweight cement block was studied. A Cold press method was selected for block manufacturing as it could gain terrific compressive strength with user-friendly operation. It was found that the saturated surface dry (SSD) condition of the straws achieved higher strength than that of the as-received (AR) condition. SSD of straw had softer and more flexibility to easily disperse in the cement matrix. Moreover, extra water in the wet SSD straws could also allow internal curing for more hydration reactions inside the specimens during their curing period. The optimal proportion for the production of rice straw based-lightweight cement block, achieving 6.43 MPa, is 0.30 of w/c ratio with 2% of straw addition in the SDD state. The outcomes could promote a value-added concept and achieve greener and cleaner production for the development of environmentally friendly alternative construction materials.