THE SUITABILITY OF LIME RICE HUSK ASH CEMENT AS CONSTRUCTION MATERIAL

Abstract

Previous studies have demonstrated that rice husk ash cement is unsatisfactory as a construction material particularly for high strength structures due to its structural instability and low strength development. In the present study a comparative analysis of the chemical composition of ordinary Portland cement and the rice husk ash cement indicated that the content of silica, potassium oxide and sodium oxide are greater in rice husk ash cement than in Portland cement while rice husk ash s deficient in calcium oxide .. However, by gradually increasing the percentage contents of silica, potassium oxide and sodium oxide in the Portland cement to the values found in the rice husk ash a new product, "Artificial Lime Rice Husk Ash" (ALRHA) cement was produced. The new product ALRHA cement compared favourably with the ordinary rice husk ash cement particularly in strength development and degree of stability. It was therefore concluded that high percentage contents of silica, potassium oxide and sodium oxide are responsible for the structural instability and low strength development of the Lime Rice Husk Ash cement. It appears therefore that the successful utilization of the Lime Rice Husk Ash cement when used as a construction material would depend largely on the successful reduction of the high percentage of silica, potassium oxide and sodium oxide to the level present in ordinary Portland cement.