Comparative assessment of fiber type effect on ultra-high-performance concrete after high-temperature heating and cooling

Ultra-high-performance concrete (UHPC) is a type of concrete with high mechanical strengths in which silica fume, quartz powder, superplasticizer and fibers, in addition to cement and water are usually used in its mixture design. In spite of vast studies on the mechanical properties of UHPC, very few comparative studies have been made on the effects of fiber types on the mechanical characteristics of this type of concrete, subjected to high thermal changes. This study aims at providing test results for the effects of temperature changes on the mechanical properties of UHPC that are reinforced with different types of fibers. Six types of fibers, either recycled or industrially manufactured, are utilized in the mixture design. After exposure to high temperature changes, compressive strength, tensile strength in bending, ultrasonic pulse velocity and sorptivity were evaluated and compared. Results of this study can be used in other research studies and can be used in decision making in industrial projects.