Fire performance of timer-concrete composite floor systems utilizing cross-laminated timber panels with self-tapping screws as shear connectors

Abstract

One of the main reasons that hinder more utilization of combustible material, such as wood, as the primary construction material in tall buildings is the required duration a structure must withstand applied loads under fire exposure without losing its structural integrity, which is refereed to the fire resistance rating required by applicable building codes. However, the increased availability of cross-laminated timber (CLT) sections in Canada and its successful use in mass timber construction have generated interest in its properties and performance when subjected to fire. Floor systems in mass timber buildings can be more robust and span longer distances by adding a top layer of concrete to form timber-concrete composite (TCC) floor systems when adequate shear connections are utilized. The primary technique for shear connections in TCC systems is a wide variety of metal connectors, with the self-tapping screws (STS) being one of the most used shear connectors. Therefore, proper design guidelines and methodologies are needed to determine the accurate fire resistance of TCC floor systems. Currently, there is no design procedure for the TCC floor systems included in the Canadian Engineering design in wood standard (CSA O86-19) but is implemented in other international design codes, such as the European codes. [...]