Thermal properties of cement mortar with different mix proportions

• Published in: Materiales de construcción (Madrid) 2020-09, Vol.70 (339), p.224-e224
• Main Authors: Shafigh, P., Asadi, I., Akhiani, A. R., Mahyuddin, N. B., Hashemi, M.
• Format: Article
• Language: English
• Subjects: Aggregates; Buildings; Cement; cement mortar; Compressive strength; Construction materials; Density; Diffusivity; heat capacity; Heat conductivity; Heat transfer; Masonry; Mechanical properties; Mortars (material); Physical properties; Pore size; Porosity; Sand; Scanning electron microscopy; Thermal conductivity; Thermal diffusivity; Thermodynamic properties; Water absorption
• ISSN: 0465-2746; 1988-3226
• DOI: 10.3989/mc.2020.09219

The energy required for the heating and cooling of buildings is strongly dependant on the thermal properties of the construction material. Cement mortar is a common construction material that is widely used in buildings. The main aim of this study is to assess the thermal properties of cement mortar in terms of its ther­mal conductivity, heat capacity and thermal diffusivity in a wide range of grades (cement: sand ratio between 1:2 and 1:8). As there is insufficient information to predict the thermal conductivity and diffusivity of a cement mortar from its physical and mechanical properties, the relationships between thermal conductivity and diffu­sivity and density, compressive strength, water absorption and porosity are also discussed. Our results indicate that, for a cement mortar with a 28-day compressive strength in the range of 6–60 MPa, thermal conductivity, specific heat and thermal diffusivity are in the range of 1.5–2.7 W/(m.K), 0.87–1.04 kJ/kg.K and 0.89–1.26 (x10-6 m2/s), respectively. The scanning electron microscope (SEM) images showed that pore size varied from 18 μm to 946 μm for samples with different cement-to-sand ratios. The porosity of cement mortar has a signifi­cant effect on its thermal and physical properties. For this reason, thermal conductivity and thermal diffusivity was greater in cement mortar samples with a higher density and compressive strength.