Analysis of Bond Behavior of FRP‐Confined Concrete Piles Based on Push‐Out Test

Abstract

Due to the significant differences in the properties (e.g., anisotropy, elasticity modulus, and surface roughness) of fibre-reinforced polymer (FRP) and traditional pile materials, research on bond behavior between FRP tube and concrete should be conducted to ensure that they can work together properly. Push-out tests on twenty-nine GFRP-confined concrete piles were performed, the influence of bond type, slenderness ratio of FRP tube, radius-thickness ratio of FRP tube, concrete stress and concrete type on bond behavior and distribution of axial strains were studied, and simplified bond-slip constitutive models based on test results were proposed. It was found that bond type was a critical factor influencing bond behavior. A smaller radius-thickness ratio, a higher concrete stress, and the use of expansive concrete were advantageous for achieving higher bond behavior, whereas the slenderness ratio had little influence on the bond behavior. The axial strain distribution of all FRP tubes demonstrated the following rules: the upper strain was greater than the middle strain, which was larger than the lower strain, but for normal concrete specimens, the strain was linearly distributed with height, while for expanded concrete specimens, the distribution curves were polylines.

Stress Analysis of Concrete Materials Based on Finite Element Analysis

“…The special-shaped wall frame system includes the cast in situ reinforced large-diameter concrete special-shaped wall frame and special-shaped column frame shear wall system used for light infilled walls and partitions. The reinforced concrete special-shaped column structure system is a special engineering structure system produced in the process of modern building structure design and construction in China, which makes the development and research of the reinforced concrete special-shaped column structure system in China ahead of the world [4]. Since the in-depth research on the technical system of reinforced concrete special-shaped column structure, considerable progress has also been made.…”