Strain hardening green cementitious composites reinforced with nanoparticles: Mechanical and microstructural properties and high temperature effect

This study investigates the effect of nano-particles on the composite's mechanical, microstructural, and high-temperature resistance by using TiO2 and Al2O3 nano-particles in different proportions in the engineered cementitious composites (ECC) composite. TiO2 and Al2O3 nanoparticles were used in three different ratios (0.5%, 1%, and 1.5%) in the ECC mixtures. Then, flexural strength, compressive strength, and ultrasonic pulse velocity (UPV) experiments were conducted on the prepared composites. The relationships between the concentration of TiO2 and Al2O3 nano-particles and the compressive strength were investigated. Scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) analyses were performed to investigate the microstructural contents of the prepared samples. In addition, the effects of high temperatures on the mechanical properties of nano-doped ECC samples were investigated at 200, 400, 600, and 800 °C. The content of 1% TiO2 (1 TiN) and 1.5% Al2O3 (1.5 AlN) nano-particles increased the compressive strength of the nano-doped-ECC samples by 19.6% and 20.2% compared to the nano-free control samples. Also, the increases in compressive strength of 1 TiN and 1.5 AlN samples exposed to 800 °C increased up to 26.24% and 34.56%, respectively.