Feasibility study of using dry sludge as filler to improve mechanical properties of concrete

Abstract

This project was conducted to study the potential of dry sewage sludge as filler to improve mechanical properties of concrete. This project is a part of larger project to find different usage from existing application of waste sludge. Controlling concrete mix ratio is 1:2:4 with water cement ratio of 0.5. Concrete mixture with different percentage of replaced fine aggregates with dry sludge is tested. Fine aggregate is replaced by 2.5%, 5.0% and 10.0% of dry sewage sludge with 0.149 mm average diameter. Specimens were cured for 7, 14 and 28 days. To achieve the objectives of the study, laboratory tests were conducted on both plain concrete and dry sludge concrete. The tests are sieve analysis, compression strength test and flexural strength test. Results from the tests showed that it is possible to used dry sludge as filler in concrete. Utilization of dry sludge can improve waste managing problem as well as conserve natural resources. Physical properties of dry sludge show that it can be used as fine aggregate. Replacement of 2.5% fine aggregates with dry sewage sludge yield the best improvement in both compressive and flexural strength.