Studies on a fly ash lightweight aggregate in foamed concrete cubes

Abstract

Fly ash is used as a partial replacement in fly ash lightweight aggregates and fly ash lightweight aggregates is used as a partial replacement in foamed concrete cubes. These materials are important in increasing the positive properties of foamed concrete cubes. The effects of using fly ash can be determined by its partial replacement in fly ash lightweight aggregates of 5%, 10% and 15%. The effects of fly ash lightweight aggregates can also be determine by its partial replacement in foamed concrete cubes of 25% and 50%. Based on the results, the density of fly ash lightweight aggregates for each sample is from 413.21 kg/mᵌ to 589.06 kg/mᵌ. While the density for foamed concrete cubes are from 1.442 kg/mᵌ to 1.498 kg/mᵌ for each sample. Besides that, the water absorption of fly ash lightweight aggregates different from 17.07% to 20.48%. While the water absorption for foamed concrete cubes are from 17.18% to 18.80% for each sample. Specific gravity for each sample of fly ash lightweight aggregates is from 1.300 kg/mᵌ to 1.692 kg/mᵌ. Besides that, the loading impact for fly ash lightweight aggregates is from 56% to 59% for each sample. Next for each sample of fly ash lightweight aggregates, compression strength achieved from 2.280 MPa to 8.781 MPa. While for foamed concrete cubes after the 28th day, each samples of compression strength is from 7.813 MPa to 13.442 MPa. In conclusion for foamed concrete cubes in this research, the suitable percentage of fly ash that can be used for partial replacement in cement is 15% and 50% for partial replacement of fly ash lightweight aggregates in coarse aggregates. These samples reach the density of 1.498 kg/mᵌ that include in the lightweight aggregates category with the compression strength of 13.442 MPa.