Experimental investigations of aluminum hydroxide nanoparticles on properties of cementitious composites using macro and micro scale tests

Abstract

The potential to use nanomaterials to produce high-performance cementitious composites is gradually developing. This study designed novel cementitious composites containing aluminum hydroxide nanoparticles (AHNPs), considering features such as amphoterism, functional groups, and compatibility with cement components. The percolation threshold of the AHNP dosage in cementitious composites was calculated as 0.5% by weight replacing cement, and cementitious composites containing 0.5% wt. AHNP have 1.11- and 1.94-fold greater compressive and flexural strength than plain cementitious composites, respectively. AHNPs increased the portlandite content and decreased the calcite content due to redox reactions and the formation of dmitryivanovite in the cement matrix. Compared with plain paste, the application of hybrid 0.3% wt. AHNPs and 0.1% wt. GO increased the compressive strength by 92.55%, flexural strength by 83.74%, fracture toughness by 5.29%, and calcite content by 35.38%. This combination also achieved increases of 72.38% in compressive strength, 18.23% in flexural strength, 10.91% in fracture toughness, and 5.18% in calcite content compared to cementitious composites modified with 0.1% wt. GO. GO and AHNPs generated a more compact structure due to their mutual hydrogen bonding capacity and thus enhanced the macro- and micro properties of cementitious composites by facilitating hydration.