Crushed-stone sand for use in the development of self-compacting concrete (SCC)

Abstract

SCCs, usually known as self-compacting concrete, are a kind of very fluid concrete having the capacity to flow without suffering any vibration. In order to reduce the possibility of bleeding and segregation, their makeup requires the inclusion of a significant number of fines. The usage of crushed sand, which is plentiful in limestone fines, may be shown to be a successful solution in terms of economics and ecology. This research examines the rheological, mechanical, and durability properties of self-consolidating concrete after adding quarry limestone fines to manufactured crushed sand (SCC). Five distinct SCC mixes were made with a consistent water-to-cement ratio of 0.40 and a cement content of 490 kg/m3 in order to accomplish this objective. The combinations substituted crushed limestone fines for crushed sand in varying proportions. The slump flow test, the V-funnel flow time test, the L-box height ratio test, the segregation resistance test, and the rheological test were all performed on the fresh SCC mixes using a rheometer. The compressive, tensile, and flexural strengths of SCC mixtures were assessed at the conclusion of the 28-day curing period. It was shown that raising the replacement amount of limestone fines in SCC mixes resulted in a decrease in both the slump flow and the yield stress when employing the two separate test modes in the fresh condition Samples of 7th and 28th day cubes were collected from the optimized mix proportion and subjected to Scanning Electron Microscope (SEM), X- Ray Diffraction (XRD). The images were interpreted and the result from micro-structural analysis were compared with their compressive strength. All of the SCC combinations examined had acceptable filling and passing capabilities, and no segregation was discovered in any of them. Using limestone fines instead of crushed sand also reduces the amount of water that is absorbed by capillaries, stops chloride ions from moving, and improves performance.