Low-carbon self-compacting glass fiber-reinforced concrete using calcium sulpho-aluminate cement and recycled concrete fine aggregate

This study presents the development and comprehensive evaluation of low-carbon self-compacting glass fiber-reinforced concrete (GRC) utilizing calcium sulpho-aluminate (CSA) cement and recycled concrete fine aggregate (RFA), targeting enhanced sustainability and durability for high-performance infrastructure applications. Through rigorous mix design optimization, the research demonstrates that substituting natural sand with RFA in CSA cement-based matrices yields a compressive strength of up to 55 MPa after 28 d, comparable to or exceeding conventional mixes, while increasing elastic modulus by approximately 15%, resulting in a stiffer, denser composite. Flexural performance tests revealed that CSA and RFA with GRC achieves a modulus of elasticity of 17 GPa and a modulus of rupture (MOR) of 3.77 kN, coupled with substantial toughness and ductility, particularly under loads. After 75 d of accelerated aging, RFA–GRC retained 50% to 70% of its initial MOR and 20% to 40% of strain to failure, outperforming traditional GRC by about 30%, confirming its superior long-term durability. Environmental analysis verifies a dramatic reduction in carbon footprint of CSA RFA GRC achieves up to 74% less CO2 emissions and 48% lower embodied energy than ordinary Portland cement controls, with values as low as 275 kg CO2/m3 and 675 MJ/m3. Practical validation through prototype drainage channels and permanent formwork further underscores the material’s viability, demonstrating excellent workability, structural integrity, and crack resistance. Furthermore, the test results establish CSA and RFA with GRC as a highly sustainable, resilient alternative, supporting circular construction and long-life design in aggressive environments.