06-01-2016, 04:42 PM
Abstract
Concrete is the most widely used construction material in civil engineering industry because of its high structural strength and stability. The concrete industry is constantly looking for supplementary cementitious material with the objective of reducing the solid waste disposal problem. Ground granulated blast furnace slag (GGBS) Rice husk ash (RHA) and Quarry sand (QS) are among the solid wastes generated by industry. To overcome from this crisis, partial replacement of natural sand (NS) with Quarry sand and partial replacement of cement with GGBS and RHA can be an economic alternative. This research is carried out in three phase, in first phase mix of M40 grade concrete with replacement of 0%,15%,30%,45%,60%,75%,90% and 100% of quarry sand with natural sand is carried out to determine the optimum percentage of replacement at which maximum compressive strength is achieved. It is observed that when natural sand is partially replaced with 60% quarry sand maximum strength is achieved. In second phase, cement is partially replaced with GGBS by 10%, 20% and 30%. In phase three, combination of GGBS and RHA is partially replaced with cement. The composition of 22.5% GGBS + 7.5% RHA with 60% of quarry sand gives good strength results.
Introduction
Concrete is a heterogeneous mix of cement, aggregates and water. The global consumption of natural sand is too high due to its extensive use in concrete. The demand for natural sand is quite high in developing countries owing to rapid infrastructural growth which results supply scarcity. To overcome from this crisis, partial replacement of natural sand with quarry sand is economic alternative. The concrete industry is constantly looking for supplementary cementitious material with the objective of reducing the solid waste disposal problem. Ground granulated blast furnace slag (GGBS), Rice husk ash (RHA) and Quarry sand (QS) are among the solid wastes generated by industry. Substantial energy and cost savings can result when industrial by-products are used as partial replacements for the energy- intensive Portland cement. This investigation attempts to study the feasibility of using locally available GGBS, RHA and QS as partial replacements for cement and sand in concrete. In this research we prepared specimen of cubes for compressive strength test, cylinder for split tensile strength test, beams for flexure strength test and permeable voids test. Three samples for each set of percentage have been taken for conducting test and average of results are taken. The samples were tested at the age of 7 days, 28 days and 56 days. The test on hardened concrete are destructive test while the destructive test includes compressive strength test as per IS: 516-1959, split tensile strength test as per IS: 5816-1999, flexure strength test as per IS: 516-1959, permeable voids test as per ASTM C642-97.
The objectives and scope of present study are –
1. To find the optimum percentage of replacement of natural sand with quarry sand at which maximum strength is obtained.
2. To use pozzolanic material such as GGBS and RHA in concrete by partial replacement of cement.
3. To conduct compressive strength test, split tensile strength test, flexural test.
4. To study and find permeable voids of the concrete mix and its relation with compressive strength of concrete.
5. To provide economical construction material.
6. Provide safeguard to the environment by utilizing waste properly.
7. To conduct acid resistant test.