Multiscale 3D finite-element modelling of the thermal conductivity of clay brick walls

Multiscale Approach of the Equivalent Thermal Conductivity of Modified Foam-Filled and Non-Filled Hollow Brick and a Brick Wall

“…Al-Hadhrami and Ahmad [2] indicated that the hollow bricks with the size of 400 (length) x 200 (width) x 200 (height) mm, made from fired red clay, exhibited noticeable thermal-insulation properties compared to concrete bricks produced by using the guarded hot-plate technique. Alghamdi and Alharthi [10] used the same dimensions, and they agree with the above researchers concerning the required thermal properties of fired red clay. Antoniadis et al [20] developed a new design with higher thermal insulation for the Greek hollow clay bricks by using the transient hot-wire technique.…”

“…(11) based on the − and the heat flux through the mortar ( ). The limitation of the paper's equations is that the equations are not applicable for non-uniform sections, e.g., the brick of Alghamdi and Alharthi [10] in case of y-and z-directions as shown in Figure 1. However, in such cases, the thermal conductivity and resistance can be found by the standard heat transfer calculations and modeling approaches.…”

“…In general, for thermal analysis, there are many experimental and theoretical approaches, and software packages have been used [11,19,28,48,49]. However, in this study, the finite element method (FEM) has been adopted by using ABAQUS software [50], which has proved its ability to model and simulate bricks under different configurations and conditions [10,51]. It has been also used to calculate the sum total of heat flux of the inner surface nodes to find the average heat flux ( ).…”

“…Three dimensions finite-element (FE) model of 400 x 200 x 200 mm hollow brick is adopted. These dimensions are the common brick dimensions in building constructions [2,10]. The red clay has been selected to be the brick material due to its desired thermal properties in front of other masonry materials such as the concrete material as explained in the review.…”

“…Increasing the thermal resistance of the building walls without affecting the structural properties has been a fundamental aspect, and it should be taken into account through fundamental design steps [3]. Therefore, another technique, it is modifying the brick design by using of air cavities in the brick or block that reduce the weight and could increase the equivalent thermal resistance [8][9][10]. In bricks, the process of heat transfer in hollow brick can be represented by conduction, natural convection, and radiation in all domains, enclosures, between inner surfaces, [1,11].…”