In other words, there is not enough data and knowledge about the thermal properties of concrete.  Consequently, more experimental researches are required to examine the effect of several factors on different types of concrete. Moreover, to evaluate the effect of using different types of concrete needed extra experimental and more research works for the effect on the energy consumption of buildings.

This means that there is a dearth of research on the concrete thermal properties. As a result, there is a need to conduct further experimental studies addressing the effect of different variables on various concrete types. Furthermore, a need is felt to carry out more experimental research investigating the relationship between concrete types and energy consumption of buildings.

 Energy conservation and thermal comfort in buildings are important topics in the construction industry. The energy required for building cooling and heating and thermal comfort depends greatly on the thermo physical properties of the construction materials (Latha et al., 2015).

Considering the effects of energy efficacy and thermal comfort in buildings is of utmost importance in the construction industry. Research efforts have reported that the thermophysical properties of the construction materials can define the energy use and thermal comfort of a building (Latha et al., 2015).

Thermal mass is defined as a material's ability to absorb, store and release heat. Thermal mass materials, such as water, earth, bricks, wood, rocks, steel and concrete act as heat sinks in warm periods and as heat sources during cool periods. High thermal mass materials maintain indoor temperatures within desirable ranges without extreme EC (Real et al., 2016).

Thermal mass is the property of materials to absorb, store, and release heat. Thermal mass materials (e.g., water, earth, bricks, wood, rocks, steel, and concrete) can play a dual role. This means that such materials can serve the purpose of heat sinks during warm periods and heat sources during cool periods. The utilization of materials with high thermal mass can result in the maintenance of interior temperatures within acceptable ranges without extreme EC (Real et al., 2016).

Employing adequate thermal mass materials can reduce the EC in buildings by at least 7–22%. The thermal performance of materials is evaluated according to their specific heat capacity (KJ/Kg °K) or heat capacity per unit volume (KJ/m3 ˚K).

The EC can be decreased by at least 7–22% when thermal mass materials are sufficiently used in buildings. The thermal performance of materials is measured by specific heat capacity (KJ/Kg °K) or heat capacity per unit volume (KJ/m3 ˚K, Willoughby, 2002; Ghoreishi et al., 2011).

Concrete is a thermal mass material mainly composed of cement, water and aggregates. Compared to other building materials such as wood, steel, and plastic, concrete is used twice as much in the construction of buildings (Oktay et al., 2015).

One of the thermal mass material that is used twice as much as other building materials (e.g., wood, steel, and plastic) is called concrete (Oktay et al., 2015). The main components of concrete are cement, water, and aggregates.