Production of Heat-Insulating Concrete Hollow Block

Hollow concrete blocks are primarily used in residential buildings, factories, and multi-storied construction. The main goal is to produce a new insulation block from lightweight concrete by mixing light expanded clay aggregate (LECA) at a specified weight percentage with gravel. A trial-and-error method was used to determine the mixture ratio (cement: sand: lightweight aggregate) of (1:1.75:3.25) by weight, with a water-to-cement ratio of 0.48. Cubic, cylinder, and block samples were prepared with various volume proportions of LECA by natural coarse aggregate in percentages of (0, 50, and 75) %. Mechanical and physical properties, such as compressive and tensile strengths, density, and thermal conductivity, were investigated at ages 7, 14, and 28 days. The test results show that incorporating LECA reduces the density and compressive and tensile strengths, and enhances the blocks' insulating characteristics. Additionally, the thermal conductivity of the prepared specimens decreased by approximately 57% in blocks containing 75% LECA. The results are promising and indicate that the present insulation block can be used in composite slabs.