Synergistic effects of SCMs and fibers on plastic shrinkage control of sustainable concrete

The construction industry’s reliance on reinforced cement concrete presents environmental concerns, including resource depletion and pollution. This study investigates sustainable alternatives by using industrial by-products, such as fly ash, blast furnace slag, and silica fume as partial replacements for ordinary Portland cement in concrete. In addition, it examines the integration of both synthetic and natural fibers to control plastic shrinkage, a critical issue for concrete durability. Through an experimental approach aligned with ASTM 157, a total of 25 concrete mixtures were tested, incorporating 30% fly ash, 40% ground granulated blast furnace slag, and 10% silica fume by mass, along with various fibers, including steel, polypropylene, glass, coir, sisal, and jute. The results indicate significant enhancements in concrete’s mechanical properties and a reduction in plastic shrinkage. Adding fibers notably increased shear resistance and reduced shrinkage by up to 40%, with steel and polypropylene fibers specifically decreasing crack dimensions by 25% and 35%, respectively. Furthermore, the use of supplementary cementitious materials (SCMs) decreased shrinkage by an additional 25%, significantly improving durability and performance. The combination of SCMs and fibers presents a promising strategy for creating environmentally friendly and resilient concrete.