Cross-laminated timber is a relatively new engineered timber material that can be used in the design and construction of modern timber buildings. A key factor that raises concerns in the wide application of cross-laminated timber is the uncertainty of its fire performance. This article describes experimental and numerical investigations on the fire behaviour of loaded cross-laminated timber panels manufactured with Canadian hemlock. A total of 10 cross-laminated timber panels with different number and thickness of layers were tested under ambient and standard fire conditions to investigate the flexural capacity at ambient temperature, and temperature distribution, charring rate, fire resistance, mid-span deflection under fire exposure. Three-dimensional finite element model was developed using the Hashin criterion and cohesive elements to predict the failure of wood and adhesive, respectively. The thermal model implicitly considers the rapidly increased temperature of inner fresh timber after the protective charred layers have fallen off. The numerical model was validated with the results obtained from experimental tests and was found to have the ability to simulate the fire behaviour of loaded cross-laminated timber panels in reasonable accuracy.

Global warming and environmental deterioration have caused socially catastrophic events, arousing people’s interest in discovering the root causes of such events. Looking for an economically efficient and highly adsorbing carbon dioxide adsorbent has become one of the research priorities. Porous zirconia is an ideal candidate material for absorbing CO2 due to its distinctive acid-base property and a large number of active sites. The present study analyzed the effects of external factors (e.g., porous zirconia, including temperature, pH value, and humidity) and internal factors (e.g., crystal structure, lattice defects, and percentage of active sites in zirconia) on the adsorption performance of porous zirconia. Porous zirconia was found to have a high adsorption efficiency at pH 3∼6 under humid conditions. When the crystal structure of zirconia was tetragonal, monoclinic, or tetrahedral, the zirconia had a larger void volume and a larger number of active vacancies and oxygen vacancies. Modifying and increasing oxygen vacancies resulted in a larger number of active sites and a greater Gibbs free energy in the ZrO2 materials and their composites.