INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 3, ISSUE 4, APRIL 2014 ISSN 2277-8616 348 IJSTR©2014 www.ijstr.org Investigation The Properties Of Concrete Containing Rice Husk Ash To Reduction The Seepage In Canals. S. I. Khassaf, A. T. Jasim, F.K. Mahdi Abstract: In this research effect of rice husk ash (RHA) on Fresh and Hardened Properties of concrete which used to reduction the seepage in the canal lining was studied. To establish the suitable proportion of RHA for the partial replacement of cement, Concrete specimens was molded with 10%, 20%, and 30% of (RHA) replacing the cement, and measured it to workability, compressive strength, splitting tensile strength, dryings shrinkage, The results were compared with the concrete mix that does not contain RHA. The obtained results indicated that it was a significant reduction of workability in fresh concrete with the increase amount of RHA content in concrete, and it was an increase in the compressive strength and splitting tensile strength by increased of RHA% until 20% , The maximum increment is around 10.5%and 11% for the compressive strength and splitting tensile strength respectively then it were decrease with the increase of RHA to 30%, the decrease was around 17 % and 10.5% for compressive strength and tensile splitting strength respectively. The test of drying shrinkage indicated that it was decreased with increased of RHA%, the maximum decreased given by 30% RHA it was about 28% of normal concrete shrinkage after 90 days age. Key word: Concrete properties, Rice Husk Ash, Seepage, canal. ———————————————————— 1 Introduction Rice husk ash, a by-product of rice processing, is produced in large quantities globally every year, About 500 million tons of rice paddy is produced in the world an annually (1) . Rice milling generates, a byproduct know as husk. This surrounds the paddy grain. During milling of paddy about 78 % of weight is received as rice, broken rice and bran .Rest 22 % of the weight of paddy is received as husk. This husk is used as fuel in the rice mills to generate steam for the parboiling process. This husk contains about 75 % organic volatile matter and the balance 25 % of the weight of this husk is converted into ash during the firing process, is known as rice husk ash (RHA) (2) . and due to the difficulty involved in its disposal, can lead to RHA becoming an environmental hazard in rice producing countries, potentially adding to air and water pollution. The use of RHA in cement or concrete as a supplementary cementing material has been increased recently. Supplementary use of RHA in cement or concrete is not a new technique but it was started since early 1970. Since then Many Research and development in various parts of the world, have shown that rice husk ash (RHA) can be used as a partial replacement for cement in concrete because of its very high silica content, where rice plant is one of the plants that absorbs silica from the soil and assimilates it into its structure during the growth (3) . it stands out as an ecofriendly, sustainable and durable option for concrete. So this research was of great importance to study the possibility of adding rice husk ash to cement used in the concrete lining canals, Since this material is available, and improves the properties of concrete, especially in reducing the leakage phenomenon. In rice producing countries like Iraq, RHA-concrete has the potential to provide a low-cost construction material produced from locally sourced, abundant materials while having the added benefit of providing a means to dispose of an agricultural waste product. Iraq provides an ideal location to explore the potential for in low-cost concrete.Mehta(1979) (4) suggested that essentially amorphous silica can be produced by maintaining the combustion temperature below 500°C under oxidizing conditions for prolonged periods or up to 680 °C with a hold time less than 1 min. Yeoh et al (1979) (5) report that RHA can remain in the amorphous form at combustion temperatures of up to 900 o C if the combustion time is less than 1 hour, while crystalline silica is produced at 1000 o C with combustion time greater than 5 min.Hwang and Wu (1989) (6) were studied the effect of different burning temperatures and the chemical composition of rice husk (Taiwan RHA). It was observed that at 400°C, polysaccharides begin to depolymerize. Above 400oC, dehydration of sugar units occurs. The study found that RHA produced by burning rice husk between 600 and 700°C temperatures for 2 hours, contains 90-95% SiO2. At 700°C, the sugar units decompose. At temperatures above 700°C, unsaturated products react together and form a highly reactive carbonic residue. Al-kadhi, (2002) (7) in his investigation the burning of rice husks was carried out in controlled temperature in order to establish the optimum burning temperature. It was found that the combustion temperature of about 550 ◦ C and duration time of 2 hours produced an ash with optimum properties. 2 Experimental Work 2.1. Materials 2.1.1 Cement Sulfate resisting Portland cement (Type V) was used in this study. The results indicate that the available cement conforms to the Iraqi specification (I-O-S) (No.5/1984) (8) . ___________________________  S. I. Khassaf, A. T. Jasim, F.K. Mahdi  Professor, Civil Engineering Department, University of Bassra, Iraq.  Assistant Professor, Civil Engineering Department, University of Kufa, Iraq.  B.Sc. Civil Engineering Department, University of Kufa, Iraq.