Numerical Evaluation of Modified Mortar Coatings for Thermal Protection of Reinforced Concrete and Steel Structures Under Standardized Fire Exposure

Abstract

This study investigates the thermal performance of 23 different mortar types, each containing different mixes, properties, and additives. A comprehensive literature review was conducted to collect experimental data on the thermal properties of these mortars, which were then used in a numerical analysis through thermal finite element modeling. The results showed that all mortar types contributed to reducing the internal temperature of structural steel and reinforced concrete elements, with performance primarily influenced by key factors such as the mortar’s thermal conductivity, specific heat capacity, thermal diffusivity, and coating thickness. In particular, the mortar with glass fiber reinforced polymer (GFRP) as a slag substitute and the mortar with expanded perlite replacing sand showed the highest thermal protection and achieved a temperature reduction on the order of 100%. In contrast, mortars containing 30% vermiculite or 15% light expanded polyvinyl chloride (PVC) as a sand substitute showed the lowest thermal performance.