Paper Title
Mechanical Performances of Rice Husk Ash-Mixed Cement Grouting in Rock Fractures

Abstract
The purpose of this paper is to assess the mechanical performances of rice husk ash (RHA)-mixed with the Portland cement for grouting material in rock fractures. The mixtures of grouting materials are prepared from RHA and ordinary Portland cement. The RHA-cement ratios are 1:10, 3:10, 5:10, and 10:10 with water-cement ratio of 1:1 by weight under curing times of 3, 7, 14, and 28 days. The tested rock specimens are sandstone and the rock fractures are artificially made in the laboratory. This research determines the suitable RHA-cement ratio that will be used as grouting materials in rock fractures. The results indicate that the average viscosity of RHA-mixed cement tends to increase as RHA-mixed cement ratio increases. The RHA-cement ratio as 5:10 that clearly showed the highest compressive strength, elastic modulus and tensile strength after 28 days curing time. In addition, this mixtures ratio represents the highest shear strength between grouting material and rock fractures in direct shear and push-out testing after 7 days curing time. Hence, this ratio probably has potential to be the suitable ratio that will be used as grouting materials and can be applied in grouting or sealing in rock fractures for the mining industry, dam foundation and rock embankments. Index Terms - Rice husk ash, mechanical properties, grouting material, sandstone