Interlocking concrete blocks for floors using high volume fly ash

Abstract

This research aims to use a high volume of fly ash partially replaced cement to produce the interlocking concrete blocks for floors according to TIS 827-2565. Fly ash was obtained from the electric thermal power plants, divided into 3 plants, namely NPS1, NPS2 and NPP5A. It partially replaced cement at 50, 60, and 70 percent by weight. The sand was used as the aggregate. The ratio of cementitious material (cement and fly ash) to aggregate was 1:2.5 by volume, adjusting the amount of water as appropriate. The samples were compressed with a hydraulic press. Compressive strength was investigated at 7 and 28 days. Water absorption was studied at 28 days. The results found that the strength index values ​​of fly ash at 28 days from NPS1, NPS2, and NP5A were 85.2%, 80.4%, and 72.4%, respectively. It has the properties of pozzolanic materials. The compressive strength decreases with increasing the percentage of fly ash replacement. The replacing 50 percent of fly ash by weight of NPS1 and NPS2 plants gave compressive strength values ​​of 46 and 51 MPa at 28 days. The compressive strength ​​passed in according to the TIS 827-2565 standard (more than 40.0 megapascals).