Experimental and Numerical Thermal Assessment of Lebanese Traditional Hollow Blocks

Abstract

Hollow-core concrete blocks constitute the main method of construction for vertical walls in Lebanon where almost all walls are masonry and use the same block shape. The detailed investigation of the main parameters involved in the heat transfer in these blocks is thus of great importance for analyzing and understanding them and providing recommendations for their improvement.This paper offers an experimental and numerical analysis of heat performance the Lebanese concrete hollow block. After validating the numerical model by comparing it to experimental results, a deep and detailed analysis is done for understanding the complexity of heat transfer phenomena inside the block. Then a parametric study is performed to understand the effect of various parameters on the overall thermal resistance of the block, these parameters include the concrete solid mixture, the cavities infill material, and the geometry configuration of the block.

Investigation of the mechanical and thermal performances of concrete hollow blocks

“…The heat flux φ (W m −2 ) and the temperature on both sides of the sample are measured simultaneously. The Fourier's law applied in unidirectional steady state conditions gives [24]:…”

“…The average initial temperature of the sample ΣT i (K) will change, as will the fluxes over each side. After the reestablishment of the steady state, the material has found a new stable state, associated with a new average final temperature ΣT f (K).During the transient phase, the relation between the stored (or released) heat energy Q (J m −2 ) and the heat fluxes difference Δφ (W m −2 ) is given by [24]:…”

“…A parametric study for different concrete mixture thermal conductivities was also presented to evaluate the effect of the concrete mixture's thermal conductivity on (7) c p = C e Fig. 3 Experimental measurement results for the concrete mixture [24] Vol:. (1234567890)…”

“…The air density was assumed to be dependent on pressure and temperature varying according to the ideal gas relation [25]. The validity of the heat transfer model inside the cavities of the blocks has been realized in previous works [24,26]. The same temperature boundary conditions applied to the block in the experimental test were imposed to the simulated block on the opposite faces, the other faces remaining adiabatic.…”

Analysis of Heat Transfer Phenomena inside Concrete Hollow Blocks

“…Finally researchers have studied experimentally and numerically the heat transfer in the building envelope, for example Sassine et al [22][23][24] proposed an experimental and numerical analysis of the thermal performance of Lebanese hollow block concrete. Then, they investigated the effect of adding expanded polystyrene (EPS) beads to the solid mixture of hollow block concrete by numerical and experimental approaches.…”