Experimental Investigation of Prestressed Concrete Beams Strengthened with Fiber-Reinforced Polymer Laminates

Karasala Mastan Rao — 2026-08-04

This study evaluates the effectiveness of externally bonded glass fibre-reinforced polymer (GFRP) laminates in improving the static performance of pre-stressed concrete beams. Fourteen post-tensioned concrete beams were fabricated and tested under progressively applied static loading, with two unstrengthened beams serving as control specimens and the remaining beams strengthened using various GFRP laminate configurations. The experimental program included beams cast with M35 and M60 concrete grades and reinforced using Chopped Strand Mat (CSM), Woven Roving (WR), and Uni-directional Cloth (UDC) laminates with different thicknesses. The influence of concrete strength, laminate type, and laminate thickness on structural performance was assessed by examining yield load, deflection, ductility, energy absorption, and failure characteristics. The findings demonstrated that the application of GFRP laminates substantially enhanced the load-carrying capacity, flexural stiffness, and ductility of the strengthened beams compared with the control specimens. In addition, Finite Element Method (FEM) simulations closely replicated the experimental results, confirming the reliability of the numerical model. Regression-based predictive equations were also developed to estimate the key structural performance parameters, providing a practical tool for the analysis and design of GFRP-strengthened pre-stressed concrete beams.

Experimental and Finite Element (ANSYS)-Based Evaluation of the Axial Compressive Behavior of CFRP-Confined Reinforced Concrete Members

A. Hemanth Kumar — 2026-09-10

Reinforced Concrete (RC) members strengthened with externally bonded Carbon Fiber Reinforced Polymer (CFRP) fabric offer a lightweight, corrosion-resistant alternative to conventional jacketing. This study presents a combined experimental and nonlinear finite-element investigation of the axial compressive behavior of CFRP-confined RC cylindrical members. Six specimens (150 mm diameter × 300 mm height), cast in M20-grade concrete with Fe500 reinforcement, were divided equally into unwrapped control and CFRP-wrapped groups and tested to failure under a Compression Testing Machine (CTM). CFRP confinement increased the average ultimate load from 558.47 to 632.3 kN (13.2% enhancement) and raised compressive strength from 31.62 to 35.80 MPa, while axial deformation capacity improved by 44.4%, reflecting a marked gain in ductility and energy absorption. Control specimens failed abruptly through vertical splitting and spalling, whereas CFRP-wrapped specimens exhibited delayed cracking and a gradual, ductile failure governed by fabric rupture or debonding. A companion nonlinear finite element model, built in ANSYS Workbench using SOLID186 elements with a bonded CFRP concrete interface, reproduced the experimental trend: the predicted ultimate load rose from 527.53 to 568.78 kN (7.82% increase), and the maximum principal stress increased from 3.77 to 5.75 MPa. Comparison of experimental and numerical ultimate loads showed deviations of 5.5% and 10.0% for the unwrapped and wrapped configurations, respectively, confirming that the calibrated model captures the governing confinement mechanics while slightly overestimating stiffness owing to the idealized bond assumption. The results substantiate CFRP wrapping as an effective, code-complementary retrofitting strategy for axially loaded RC members and demonstrate that validated ANSYS simulation can reliably support design-stage prediction of confined member response.

Journal of Ceramics and Concrete Sciences (e-ISSN: 2582-1938) (p-ISSN: 3049-0626)

Experimental Investigation of Prestressed Concrete Beams Strengthened with Fiber-Reinforced Polymer Laminates

Experimental and Finite Element (ANSYS)-Based Evaluation of the Axial Compressive Behavior of CFRP-Confined Reinforced Concrete Members