Investigation of the mechanical and thermal performances of concrete hollow blocks

Abstract

In order to improve the thermal performance of external masonry walls, the impact of the blocks’ internal configuration on both their mechanical strength and thermal properties is numerically investigated. Ten different configurations with approximatively similar void ratios of about 40% (38.25–40.5%) and same external dimensions (40 cm × 20 cm × 10 cm) were compared thermally and mechanically in order to investigate the effect of bulkheads on their performance and to promote some design guidelines. The complexity of the heat transfer phenomena inside the blocks as well as the stress distribution for vertical and lateral loads are detailed, leading to a better understanding of their thermal and mechanical behaviors. The numerical results indicated that the longitudinal bulkheads improve the thermal resistance of the blocks and thus reduce the heat flux passing through the blocks, while the transversal bulkheads reduce the thermal performance of the hollow blocks by creating heat bridges inside their structure. On the other hand, the mechanical behavior of the investigated blocks varies very slightly between the investigated models in vertical compression in the z-axis direction which reduces the influence of this parameter in the selection of the best shape configuration. However, the mechanical resistance to side compression increases by increasing the transversal bulkheads and decreasing the number of longitudinal bulkheads.