Effect on the compressive and tensile strength of polypropylene fiber reinforced concrete after exposure to fire temperature

Fire is one of the major factors that may cause severe damage to concrete structures and repairing and rehabilitating these structures have costly processes. One of the possible alternatives in dealing with this concern is reinforcing the concrete structures with fibers such as polypropylene fibers. A study was done on strengthening concrete with the use of applied polypropylene fibers, analyzing the compressive and tensile strength of Polypropylene Fiber Reinforced Concrete (PFRC) cylinders being affected by exposure to fire with a temperature of 300 degrees Celsius. Experiments on 150 concrete cylinder specimens were conducted having dimensions of 100 mm in diameter x 200 mm in height with polypropylene fiber contents of 0 kg/m3, 0.35kg/m3, 0.70 kg/m3, 1.05 kg/m3, and 1.40 kg/m3. The study used the paired sample T-Test to check for the significance of the results with respect to the control specimens having no fiber content. In this study, particularly with a mix design of 25 MPa, the use of polypropylene fiber content of 0.35 kg/m3 resulted in the enhancement of compressive strength, while 1.40 kg/m3 fiber content enhanced the tensile strength of concrete after exposure to fire. The concrete without fiber resulted in a higher rate of strength reduction compared to fiber-enhanced concrete with a difference of 5% in reduction for both the compressive and tensile strength. From the results obtained, fibers enhanced both the compressive and tensile strength of concrete for every hour of exposure to fire