Effect of varying nano-boron nitride content on foamed concrete containing titanium dioxide nanoparticles

This study focused on investigating mixing boron nitride (BN) and titanium dioxide (TiO₂) nanoparticles in enhancing the foamed concrete (FC) characteristics. Despite the presence of independent studies on each material addition, there is little study on their combined effects, especially with enhancements in durability, mechanical properties, and thermal performance of FC for sustainable building usage. The current research aims to examine the effects of varying BN doses (0.025-0.1% by weight of cement) with the use of constant 1% TiO₂ on fresh characteristics, microstructure, pore structure, mechanical performance, shrinkage, and thermal behavior. The results showed a slight reduction in slump and setting time, accompanied by a rise in dry density. At 0.075% BN, the 28-day compressive, flexural, and splitting tensile strengths increased by 44.27%, 52.1%, and 57.14%, respectively. Thermal conductivity increased by 7.2%, whereas shrinkage decreased by 52.30% at 28 days. Mercury intrusion porosimetry (MIP) proved the enhanced pore architecture characterized by a reduced average pore diameter and an increased volume proportion of fine capillary pores. The findings demonstrate the capability of the BN-TiO₂ hybrid system to greatly improve the durability and thermal performance of FC, causing an increase in service life and a decrease in environmental impact.