A study on acoustic emission of steel fibre concrete containing RHA as partially cement replacement / Siti Zubaidah Bibit

There has been a tremendous increase in the use of mineral admixture by industries during the late 20th century and the rate is expected to increase. Concrete is an artificial material, which is made up of cement, fine aggregates, coarse aggregates and water. The increasing demand for cement and concrete is met by the partial cement replacement by addition of supplementary cementing materials which leads to several improvements in the concrete composites and to the overall economy. This paper describes the acoustic emissions (AE) characteristics of steel fibre concrete containing black rice husk ash (BRHA) and white rice husk ash (WRHA) as partially cement replacement. The rice husk ash (RHA) was added to concrete as it is a good pozzolanic material. It can be applied for various applications such as infrastructure elements. Therefore, this study addressed three aims. Firstly is to identify the workability of the steel fibre concrete containing WRHA and BRHA as partially cement replacement at certain dosage levels based on cement weight. Secondly, is to compare the compressive strength of steel fibre concrete containing WRHA and BRHA at the age of 7, 14 and 28 days. Lastly, is to propose a new characteristic of steel fibre concrete containing WRHA and BRHA as partially cement replacement using acoustic signal strength at 7, 14 and 28 days. A total of 54 cubes were compressed in conjunction with AE technique. Three dosage levels of RHA were prepared namely 0 %, 5% and 10 % of RHA with 1 % of steel fibre in the concrete mix. The dosages levels were prepared for both BRHA and WRHAs. The data was recorded to compare the effect between white and BRHA in the steel fibre concrete. Then, the AE characteristics were identified. It is found that concrete with WRHA has higher compressive and higher signal strength than BRHA.