Role of CTAC Surfactant in Enhancing the Physical and Microstructural Properties of Sustainable Cementitious Pastes

This study examines how the cationic surfactant cetyltrimethylammonium chloride (CTAC) affects the microstructural and physical characteristics of environmentally friendly, sustainable cementitious pastes. By systematically analyzing the density, air content, water absorption, thermal conductivity, and topography of hardened cementitious pastes, the study assesses the trade-offs between thermal insulation and structural integrity brought about by CTAC surfactant. The findings indicate that at 2% concentration, CTAC dramatically increases porosity (up to 49.4%) and reduces thermal conductivity (0.24 W•m⁻¹•K⁻¹), but at the expense of compressive strength (79% compared with control). Changes in hydration disruption and pore structure lead to an increase in water absorption from 2.1 to 6.8%. According to the study, the best range for mechanical and insulating viability was between 0.5% and 1.0% CTAC. These results underscore the potential of CTAC in creating lightweight, thermally efficient building materials and also highlight the importance of tuning the concentration to achieve optimal performance and durability.