No abstract

No abstract

No abstract

Reinforced concrete sandwich wall panels are developed to reduce the effect of thermal transmission across the wall systems. The reduction of the thermal transmission is achieved through incorporation of an insulating layer. However, this insulating layer led to a reduction of structural performance. The provision of shear connection in the sandwich system improved its structural integrity and increased with increase in a number of shear connectors. However, if the shear connectors are placed directly across the layers of the concrete wythes, it will decrease its thermal efficiency. The thermal and structural performance works in contrary effect to an increasing number of shear connectors. Hence, optimizing both structural and thermal efficiencies simultaneously in reinforced concrete sandwich system has been a challenge for a very long time. Therefore, this paper presents an alternative approach focusing on the thermal path method to produce an optimum shear connector used. This approach eliminates the direct transmission path between the two wythes and, at the same time, avoids the use of alternative materials such as fibre-reinforced polymers which could be uneconomical. With this method, both thermal and structural efficiencies are optimized using only conventional concrete and steel materials.

Precast concrete sandwich panels (PCSP) are energy efficient building system that is achieved through an insulation layer created between the concrete wythes. The insulation layer is usually of low bearing strength material making it more applicable for non-structural building systems. Hence, shear connectors are introduced to improve its structural capacity, which subsequently degrades it thermal performance by serving as thermal bridges across the panel. This article review researches of alternative materials and methods used to improve the thermal efficiency as well as reduced the strength loss due to insulation in PCSP. The alternative materials are basalt fibre reinforced polymer (BFRP), carbon fibre reinforced polymer (CFRP), glass fibre reinforced polymer (GFRP), and foam concrete which are selected due to their low thermal conductivity for use in shear connection. While thermal path method has been used to prevent the effect of thermal bridges. Although, some of these materials have successfully achieved the desirable behaviours, however, several undesirable properties such as brittleness, bond slip, the sudden crushing of the panel system, and FRP failure below its ultimate strength were observed. Hence, the practicality of the alternative materials is still questionable despite its higher cost compared to the conventional steel and concrete used in the PCSP system.