Thermal performance and reduced carbon footprint of precast concrete sandwich wall panels (PCSWPs) with composite shear connector – an experimental assessment

Abstract

ABSTRACT The objective of the present work is to compare the thermal performance of precast-reinforced sandwich wall panels to that of precast-reinforced concrete wall panels. The variables used in this investigation are two different insulation materials (expanded polystyrene (EPS) and extruded polystyrene (XPS) and three different connectors (steel, glass fiber (GFRP)-wrapped steel, and aramid fiber (AFRP)-wrapped steel). A thermal analyzer setup was developed to investigate the heat transfer between the exterior and interior of the panels. The results showed that sandwich wall panels had better thermal resistance compared to the precast concrete wall panel. The temperature on the interior surface of the control specimen was 44°C after the stipulated test period. According to the experimental findings, inclusion of the insulation layer (no connectors) reduced heat transfer by 7.4°C for XPS and 6.7°C for EPS. The temperature on the interior surface was reduced only by 1.6°C and 3.6°C for sandwich panels with steel shear connectors and EPS and XPS as insulation material, respectively, indicating thermal bridging. Diminution of temperature on the interior surface of the sandwich panels with FRP-wrapped connectors varied between 5°C and 7.1°C compared to control specimen as the corrugated C-type fiber-wrapped shear connectors significantly decreased the thermal bridge between layers. In sandwich wall specimens, CO2 emissions from concrete were decreased up to 33%. Embodied carbon during the manufacturing of these panels was also compared, and it was found that the carbon emission was reduced up to 21% in the precast sandwich panels when compared to the precast reinforced wall panels.