Structural Fire Performance of Fiber-Reinforced HSC Beams Using Opensees Software

Abstract

Fire resistance is one of the significant properties of the normal-strength concrete, however, the new types of concretes such as fiber-reinforced concrete (FRC), high-strength concrete (HSC), Self-consolidating concrete (SCC), and Fly-ash concrete (FAC) may not show the same level of resistance to fire. It is because of the quicker dilapidation of strength at higher temperatures and the occurrence of fire-induced spalling. Structures modelling using computers subjected to extreme dynamic and static loads (such as wind, snow, earthquake, and impact) using finite-element software are very common and extensively being used in construction industry. However, to study the structure response of fire, highly tedious nature of modelling the full (often coupled) sequence of a realistic fire scenario, heat transfer to structure and structural response is required and only a few of the top consulting engineers in the world truly specialize in this niche area (Jiang et al. 2013). Tests to judge and quantify the structural fire performance of High Performance Concrete (HSC) are very expensive, time consuming and limited in varying parameters. Computer simulations/modelling is an alternative which is practicable, reliable and has versatility in varying parameters. There are currently very limited data on the high-temperature tensile strength properties of HSC, fiber-reinforced HSC (FRHSC), SCC, and FAC. There is a need to simulate the high-temperature tensile strength properties of HSC, FRHSC, SCC, and FAC. An object-oriented software framework, known as OpenSees which is the acronym of Open System for Earthquake Engineering Simulation created at the National Science Foundation. It facilitates users to generate finite element applications for simulating the structural and geotechnical response systems subjected to earthquakes (Usmani et al. 2012). The OpenSees Developers Group at the University of Edinburgh has included thermal capabilities in OpenSees. The advantage to extend existing finite-element codes is due to its ability to perform multihazard vii type analysis as opposed to creating fire-specific applications, e.g., fire succeeding to earthquake. The OpenSees software is open source and object oriented framework that’s why it is used for this purpose. The OpenSees framework was initially designed for the earthquake analysis of structures and is extended by the addition of new concrete classes for temperature distributions across element cross sections, thermal loads, and material laws based on Eurocodes (Jiang et al. 2013). This study is carried out to enable thermomechanical analysis of High Performance Reinforced beams with and without fibers) using software framework of OpenSees.