Recycled Chopped Rice Straw- Cement Bricks: Mechanical, Fire Resistance & Economical Assessment

In Egypt burning of rice straw releases large amounts of air pollutants causing serious environmental problems. This paper addresses the recycling of chopped rice straw to produce light weight cement bricks. Different tests were performed to evaluate the rice straw brick (R-brick) with proposed mix proportions. Its weight is 25% lighter than the traditional ones. Indirect fire exposure tests were performed in accordance to the ASTM 119-00A standards to compare fire exposure behavior of the R-bricks to market cement bricks. One and two hours exposure tests were performed, with temperatures ranging between 300 and 800 o C. Both types of bricks did not suffer any significant loss in compressive strength when exposed to 300 o C for 1hour. A loss of 70% in compressive strength of the rice-straw cement brick was reported when exposed to 800 o C for 1 hour and 80% for 2 hours fire exposure. The economical investigation showed that the R-bricks under study cost 25% less than the standard cement brick. It was concluded that the proposed R-bricks provides an economical, light weight brick, with competing thermal insulation properties, while maintaining adequate mechanical properties, and fire resistance.