A Study on Using Crushed Sand to Replace Natural Sand in High-Strength Self-compacting Concrete Towards Sustainable Development in Construction

In recent years, the use of natural sand to produce concrete has led to increased demand for sand quarrying, resulting in this valuable resource exhaustion. Therefore, there should be synchronous solutions to limit the use of resources that are gradually depleted, contributing to environmental protection. One of the solutions is to use crushed sand to replace natural sand as aggregate in concrete, especially the study of using crushed sand to make high-strength self-compacting concrete. Crushed sand is an aggregate of angular shape and surface roughness that hinders the self-compacting of the concrete mixtures. Combination with fine mineral admixtures will be a good solution to improve the rheological properties of the concrete, i.e. reducing the internal friction between the angular particles in the paste system, increasing the ability to "lubricate" the aggregate particles, thereby creating excellent workability and self-compacting ability for concrete with slump flow of 820 mm and flow time of 4.5s, the ability to flow through reinforcing steel meets the technical requirements of EFNARC and compressive strength at the age of 28 days reaches over 85MPa.