Developing and Investigating the Performance of Thermal Insulation Lightweight Sandwich Wall Panels

This research aims to develop and investigate the performance of sandwich wall panels (500 mm height × 500 mm width × 200 mm thick) with two outer concrete layers and inner expanded polystyrene layer. The test parameters include the concrete mix type of the two outer concrete layers where different ratios (53, 68, and 84%) of polystyrene beads and vermiculite aggregates were used to replace the natural coarse aggregates. The effect of using glass fiber reinforced (GFRP) shear ties to connect the two outer layers of the panels was also investigated. The average density, compressive strength, and thermal conductivity of the sandwich panels with normal aggregates were 750 kg/m3, 11.3 MPa, and 0.68 W/m.K, respectively. Using the GFRP shear ties was effective to connect the two outer layers of the panels. The results revealed that as the amount of the polystyrene beads and the vermiculite increased, the density, the compressive strength, and the thermal conductivity of the sandwich panels decreased. These values ranged from 596 to 486 kg/m3, 4.21 to 2.02 MPa, and 0.41 to 0.25 W/m.K, respectively, for the panels with polystyrene beads. For the panels with vermiculite aggregates, these values were 646 to 626 kg/m3, 3.14 to 1.96 MPa, and 0.46 to 0.34 W/m.K, respectively. This indicates that the panels with polystyrene beads were lighter, stronger, and had better thermal insulation properties. Using of the developed panels will help to reduce the self-weigh of walls resulting in smaller structural elements. In addition, the excellent thermal properties of the developed panels are expected to reduce the power consumption in buildings.