Journal of Cold Regions Engineering

Energy efficiency of the built environment greatly depends on the performance of the insulating materials used in the building envelope construction. Vacuum insulation panels (VIPs) offer excellent thermal resistance properties that can enhance the energy efficiency of the insulating systems and provide savings in energy consumption. However, VIP systems are virtually unknown and rarely used for building construction in North America. There is a need to investigate the use of VIPs in various components of building envelopes and their long-term performance. The National Research Council, Canada, Institute for Research in Construction is investigating a number of fundamental aspects related to the performance and construction of VIPs, which this paper discusses. More specifically, it reviews the underlying basics behind the functioning of VIPs and presents results from the investigation into the development of alternative core materials for VIP construction.

The Qinghai-Tibet railway, the highest railway in terms of elevation, was built under the harshest of weather conditions in the world. A new technique, called the ventiduct embankment, was used for the first time in railway construction in the Qinghai-Tibet permafrost region of China to overcome the specific difficulties of the permafrost plateau. To evaluate its effectiveness, several full-scale test embankments were constructed at a representative field site, the Qingshuihe experimental section. The effectiveness of the ventiduct embankment structure has been verified by comparing it with the performance of the nearby control embankment in terms of permafrost table, settlement, and thaw depth. These observations are presented in this paper. The ventiduct embankment structure based on this study has been adopted in Qinghai-Tibet permafrost railway construction.