Study of temperature effect on macro-synthetic fiber reinforced concretes by means of Barcelona tests: An approach focused on tunnels assessment

Abstract

This paper presents an experimental investigation on the applicability of the Barcelona (BCN) test to evaluate the mechanical properties of a Macro-Synthetic Fiber Reinforced Concrete (MSFRC) submitted to high temperature environments (up to 600°C). BCN tests demonstrated that the MSFRC gradually loses tensile strength an energy consumption density with increasing temperature. Temperatures of 400°C and 570°C shown to be critical to the MSFRC mechanical performance. The residual mechanical behavior of the macro-synthetic fibers was not affected by the temperature up to 100°C. For higher temperatures, the reinforcement showed that may lose part of its crystallinity compromising the MSFRC post-cracking performance. The constitutive model used to determine the stress-strain curves of the MSFRC was capable to reproduce the composite behavior after the event of a fire.

Role of macro fibers (steel and hybrid-synthetic) in the residual response of RC beams exposed to high temperatures

“…13. Also, the shaded area represents reported data for residual compressive strength of fibrous concrete done by other researchers [13,14,19,27,[38][39][40] (Fig. 13).…”

“…Also, Rudnik and drzymala [25] used monofilament and fibrillated in concrete at different sizes and indicated the kind and the amount of PP fibers on the thermal stability are not significant. Notwithstanding comprehensive study around PP fibers, far fewer investigations have been conducted on the effect of hybrid macro-synthetic fibers on concrete at high temperatures while a certain dose can improve the residual mechanical properties of concrete, together with minimizing the proportion of spalling [26,27]. Therefore, it benefits ductility under compression and energy absorption capacity under tension [27].…”

An Overview on the Application of FRC as a Structural Material in Brazil and Future Trends

“…This concern is emphasized in Brazil by the fact that there are large numbers of tunnels running on soft soils. For this reason, some researches are being developed in order to parameterize this behaviour [15]. This is particularly important because there are a large number of suppliers of synthetic macrofibres, which are more susceptible to the action of high temperatures.…”

A Study of the Flexural Behavior of Fiber-Reinforced Concretes Exposed to Moderate Temperatures

“…On the other hand, other experimental investigations demonstrated that MSFRC mechanical properties are affected at temperatures mainly above 100 • C. For instance, Strauss Rambo et al [25] showed that the effect of temperature on the mechanical behavior of MSFRCs in the Barcelona Test was very similar to that known for conventional concrete concerning the loss of mechanical strength and elastic modulus up to 100 • C. These last works are in agreement with the information from the macrosynthetic fiber supplier, who guarantees performance below the melting point. Moreover, Hannat [26] concluded that synthetic fibers are durable inside the concrete matrices, and these have been shown to give a post-crack behavior over many years.…”