Title:
Design Optimization and Structural Application of High Strength Fiber Reinforced Concrete
Author(s):
Butler
Publication:
Web Session
Volume:
ws_S23_Butler.pdf
Issue:
Appears on pages(s):
Keywords:
DOI:
Date:
4/2/2023
Abstract:
Ultra-high-performance concrete (UHPC) and high strength concrete (HSC) are commonly differentiated from normal strength concrete based on compressive strength. High strength, fiber-reinforced concrete (HSFRC) bridges between HSC and UHPC and has superior mechanical properties compared to normal strength concrete, including higher compressive strength, elasticity, and durability. In this project, four different HSFRC mix designs were tested based on distinct aggregate gradations. In order to achieve an optimal concrete strength, each mix's aggregate gradation was intentionally varied to match prior research while using locally sourced materials. The 2-inch cube compressive strength reached a maximum average value of 15,700 psi. The mix design model with the highest strength was then selected and used to create composite beams. Twelve reinforced concrete, rectangular beams were used in the tests. Each beam contained normal weight concrete with a 28-day compressive strength of 4,200 psi and No. 4, grade 60 reinforcing bar on the tension side of the beam. The 7-ft long beams had a 3.5 in. wide by 7 in. tall cross section, including a 1/2 in. thick HSFRC overlay that was cast against a roughened beam surface. The surfaces were roughened using a wire brush and had an average ICRI roughness of 2. The HSFRC laminates were applied to either the tension side, compression side, or both sides of the reinforced concrete beams. All beams were tested as simply supported beams with a single point load at midspan. Ductility, moment capacity, shear strength, and failure type were compared. The results indicate that by placing HSRFC laminates strategically on a reinforced concrete beam, the strength can be increased compared to the control specimens.