AN EXPERIMENTAL INVESTIGATION ON CONCRETE WITH PARTIAL REPLACEMENT OF CEMENT WITH BENTONITE CLAY AND RICE HUSK ASH

Concrete is the major building material which is being used in construction industry throughout the world. It is an extremely versatile material and can be used for all type of structures. Concrete is a combination of cement, fine aggregates, coarse aggregates and water, which are mixed in a particular proportion to get required strength. Cement is the most important constituent material, since it binds the aggregates and the process of manufacturing of cement is an energy intensive process besides polluting the atmosphere releasing of greenhouse gases like carbon-dioxide threatens to global warming also. To overcome this drawback there is a search of many mineral admixtures which can replace optimum content of cement in concrete. In view of the above drawback, this study is to reduce the effects caused using cement in concrete. Therefore, two materials like “Bentonite and Rice husk ash’’ which are easily available are considered for partial replacement of cement in concrete. Bentonite is an eco-friendly material, didn’t cause any damage to the environment. It can be used as a binding material which obeys pozzolanic properties. In India rice milling produces a by-product which is known as Husk. This husk is used as fuel in rice mills to produced steam for boiling process. This husk contains near about 75 % organic matter and the remaining 25% of this husk is modified into Ash during the firing process which known as rice husk ash (RHA). The rice husk ash (RHA) contains nearly about 85 % to 90 % amorphous silica. In this study an optimum content of up to 20% is considered as partial replacement of cement by bentonite and rice husk ash about maximum of 5% is considered. The individual material mixes and combined material mixes are designed. Such that for those mixes cubes and cylinders are casted to determine the properties. Three types of tests were conducted on concrete namely physical, mechanical and durability. The physical tests on cement are initial setting time, final setting time, consistency, specific gravity and soundness test and on aggregates are sieve analysis, fineness modulus and specific gravity. The mechanical properties like compressive strength on cubes at 7, 28, 56 and 90 days, split tensile strength test on cylinders. The durability tests like acid attack test and sulphate test are conducted. The above tests were going to conduct on the concrete with partial replacement of cement by rice husk ash and bentonite.