Mechanical properties and material characterization of cement mortar incorporating CNT-engineered polyvinyl alcohol latex

Abstract

To overcome the highly brittle nature of cementitious materials, our study aims to explore the potential of incorporating nano-engineered polyvinyl alcohol (PVA) latex in cement mortars. Hydroxyl carbon nanotubes (CNT-OH) were used to enhance the mechanical properties of PVA latex, and the resulting CNT-OH/PVA latex was used to improve the mechanical properties of cement mortars. The morphology and microstructure of CNT-OH/PVA latex and resulting mortars were characterized by SEM, FTIR and XRD. Results showed that incorporating 10 wt% of CNT-OH increased the tensile strength and modulus of solidified PVA latex by 1.56 times and 16.6 times, respectively. CNT-OH/PVA latex increased the compressive strength, flexural strength, fracture toughness and fracture energy of cement mortars by 14.3%, 39.4%, 55.4 % and 134.7%, respectively. The positive effect of CNT-OH/PVA latex on mechanical properties of cement mortars attributed to 1) uniform dispersion of CNT-OH/PVA latex in mortars, 2) acceleration of hydration, 3) chemical and hydrogen bonds between CNT-OH/PVA latex and cementitious matrix; and 4) prevention of cracking and refinement of microstructure in mortars. These findings can provide new insights into the design of high-performance cementitious materials.