Experimental Investigation of CFRP High-Strength Concrete Beams Incorporating Recycled Concrete Aggregate
Year: 2025
Type: article
Abstract: This research investigates the structural behavior of high-strength concrete beams reinforced with carbon fiber-reinforced polymer (CFRP) bars and varying percentages of recycled concrete aggregate (RCA). The study examined 15 reinforced concrete beams (200 × 250 × 2000 mm) constructed with different RCA proportions (0%, 25%, 50%, 75%, and 100%) and tested at three shear span-to-depth ratios (a/d = 1.5, 2.5, and 3.5), addressing a critical knowledge gap in sustainable structural engineering. Specimens exhibited compressive strengths of 55–67 MPa and reached ultimate load capacities of up to 198.4 kN. Notably, beams with 75% RCA achieved 35.7% higher capacity than control specimens at a/d = 1.5, challenging conventional expectations about RCA performance. Failure modes transitioned from shear-dominated at a/d = 1.5 to flexure-dominated at a/d = 3.5, with optimal ductility indices (up to 2.75) observed at a/d = 2.5. Statistical analysis revealed significant correlations between a/d ratio and performance metrics, with a perfect parabolic relationship for the ductility index (R2 = 1.0, p<0.001). Comparison with ACI 440.1R15 predictions showed generally conservative estimates (mean experimental-to-predicted ratio = 1.02, COV = 16.9%). The findings demonstrate that high-strength concrete can successfully incorporate substantial RCA quantities (up to 75%) without compromising performance when using CFRP reinforcement, potentially reducing virgin material consumption by approximately 33% for sustainable construction applications.
Source: Buildings
Institution: Erbil Polytechnic University
Language: English
Subfield: Building and Construction
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W4409705960