Numerical and experimental study of Yellow River sand in engineered cementitious composite

Engineered cementitious composites (ECCs) represent a significant advancement in concrete technology, addressing the issues and limitations of conventional concrete and environmental challenges related to sedimentation in rivers such as the Yellow River in China. This study investigates the integration of Yellow River sand (YRS) into ECC mix designs for sustainable development. YRS replacement rates (0, 25, 50, 75 and 100%) with quartz sand are systematically analysed through flexural, compressive, uniaxial tensile and four-point bending tests. In addition, scanning electron microscopy and mercury intrusion porosimetry tests are conducted to investigate the micro-mechanical properties. The results reveal that the optimal mechanical performance with 100% YRS substitution improves the compressive and flexural strengths to 26.4 and 11.5 MPa, respectively. These values are 6.20% lower than the those of the 0% substitution rate. Notably, a 100% replacement maintains an ultimate tensile strain of 3.71%, improving the crack width and spacing compared with those at 0%. The average crack width and spacing decrease by 4.87 and 11.2%, respectively, compared with those of 0% substitution. The four-point bending test results show the highest ductility at a 75% substitution rate. Furthermore, a finite-element method model of ECC beams with YRS is developed and validated under the same loading conditions as the experimental data. This study recommends an analytical method for predicting flexural strength compared with the experimental data, enhancing its suitability for sustainable engineering applications.