Compressive behaviour of concrete columns confined with textile reinforced concrete composites

Abstract

The enhancement of strength and deformation capacity in confined concrete members could be achieved through the application of advanced composite materials. Textile reinforced concrete (TRC), a novel cement-based composite material, is considered as a viable alternative to fiber reinforced polymer (FRP) sheets, addressing the limitations associated with organic resins. This study delved into the impact of various parameters, such as cross-section shapes, concrete strengths, and the number of TRC layers, on the confinement effect. The results reveal a consistent augmentation in both axial compressive strength and deformation capacity of confined concrete with an escalation in the number of TRC layers, irrespective of the cross-sectional configurations. Notably, the maximum enhancements in axial peak stress for rectangular, square, and circular specimens are recorded at 45.96 %, 49.98 %, and 90.06 %, respectively, accompanied by corresponding increases in axial strains of 56.28 %, 53.74 %, and 86.00 %, respectively. The effectiveness of TRC confinement exhibits a substantial correlation with the geometry of the cross-sections. The circular ones have higher utilization rates followed by the square ones, and the rectangular ones with section aspect ratio greater than 1.0 have the lowest utilization rates. Furthermore, an evaluation of existing confinement identification models indicates that both the Mirminan Model and Wu Model could effectively delineate the hardening and softening characteristics of circular and rectangular specimens. However, there exists scope for improving the accuracy of these models. Therefore, a novel modified identification model, predicated on the Mirminan model, was proposed to refine the confinement assessment process. The revised modified confinement ratio (MCR) is recommended at a value of 0.045, aiming to elevate the precision and reliability of confinement evaluations in concrete structures.