Thermal performance of precast concrete sandwich walls with a novel hybrid connector

This paper presents the experimental and numerical studies on the thermal responses of precast concrete sandwich (PCS) walls with a novel hybrid connector. The hybrid connector is wrapped with nylon, which is shown to reduce the thermal bridge and improve the thermal performance of PCS wall. In the first part of this work, four PCS walls were fabricated for the experimental studies and the effects of hybrid connector, insulation layer thickness and insulation material on the thermal performances of PCS walls were experimentally evaluated. Then, the finite element (FE) method was adopted to conduct the heat transfer analyses on PCS walls. The accuracies of the FE models were verified via comparing the temperature and thermal transmittance versus time of PCS walls obtained from experiments and FE analyses. The FE models were subsequently used to investigate the effects of wrapped nylon, thermal conductivity, connector spacing, central rebar diameter and insulation layer thickness on the thermal performance of PCS walls. It was found that the thermal performance of PCS wall could be improved via wrapping the connector with nylon, reducing the materials' thermal conductivities, increasing connector spacing and insulation layer thickness as well as reducing central rebar diameter.