The Effect of Difference Temperature Exposures on Steel Fiber Reinforced Recycled Aggregate Concrete

The concrete industry has a lot of challenges over the use of natural aggregate resources, which are gradually being depleted and the amount of construction and demolition wastes. To solve these problems, this paper examines the performance of recycled aggregate concrete that has been strengthened with different proportions of steel fiber. Cubes (100 mm x 100 mm x 100 mm) and prisms (500 mm x 100 mm x 100 mm), concrete were cast and cured after 7 and 28 days, and exposed to two temperatures of 100 °C and 200 °C. Several tests were conducted, such as compressive strength, flexural and Ultra Pulse Velocity Test. The result of the compressive strength test indicated that the maximum strength was recorded at 0.5 % fiber content with 28.47 MPa at 28 days, the same mix giving a higher strength at 100 °C and 200 °C of 27.15 MPa and 27.12 MPa, respectively. Flexural strength correspondingly also showed the highest value of 1.0 % fiber with a value of 9.16 MPa in 7 days and 14.59 MPa in 28 days. As the fiber content increased, the cubes (2.01 % at 7 days, 1.71 % at 28 days) and prisms (1.21 % at 7 days, 1.75 % at 28 days) recorded 1.5 % fiber to be the lowest in water content absorption. UPV tests indicated better internal properties, with the peak value of 8.55 km/s at a fiber content of 1.5 %, compared to 5.12 km/s in the control. Mechanical properties were reduced under high temperatures, but the damage was and was largely overcome due to steel fibers. These results indicate that recycled aggregate concrete with steel fibers can be a desirable construction material with exposure to temperature.