Effect of Thermal Bridges on Thermal Conductivity of Lightweight Block Units

Abstract

The objective of this study is to develop lightweight hollow concrete blocks for use as partition walls instead of load-bearing walls. These blocks aim to improve thermal insulation by reducing heat transfer through cavities of varying dimensions and shapes, thereby minimizing thermal bridges and enhancing thermal resistance. Six foam ratios (1.0, 1.5, 2.0, 2.5, 3.0, and 3.5 L/m³) and seven cement-to-sand ratios (1:1.5 to 1:2.5) were tested. Experimental tests included compressive strength, wet and dry density, water absorption, and thermal conductivity on blocks with different cavity shapes (B0–B6). To evaluate thermal behavior, the blocks were also exposed to heat at 300°C. Wall thicknesses of 30, 35, and 40 mm were examined. Overlapping openings were designed to extend the heat transfer path, improving insulation. The use of foam enhanced thermal performance, reducing energy consumption and supporting sustainability through efficient heat insulation.