Fire Resistance of Cross-Laminated Timber Panels Loaded Out of Plane

Abstract

This paper describes bending tests at ambient temperature and large-scale fire tests of cross-laminated timber (Xlam) floor panels. Three specimens exposed to standard fire curve were loaded out-of-plane with different levels of uniformly distributed load, and in two cases collapse was reached. Other unloaded panels were protected using different cladding systems with the aim to investigate their thermal behavior. Experimental data obtained from the tests and discussed within the paper includes modulus of elasticity and bending strength at ambient temperature, temperature distribution, charring depth, charring rate, residual cross section, midspan deflection, and time to failure in fire conditions. This data was compared with numerical results obtained by implementing a finite-element model in Abaqus software package for sequential thermal and structural analyses, demonstrating the accuracy of the model. The overall fire performance of the Xlam panels was satisfactory; times to failure of 99 and 110 minutes were found, respectively, for the unprotected and protected panels loaded with 21% of the mean failure load at ambient conditions.