INFLUENCE OF CURVATURE ON TENSILE BEHAVIOR OF PBO-REINFORCED CONCRETE

Abstract

A key approach for reduction of resource consumption and carbon dioxide emissions in the construction sector is to preserve and strengthen existing structures. Innovative composite materials such as carbon-reinforced concrete offer new opportunities for durable and efficient structural strengthening. While the tensile behavior of carbon-reinforced concrete has been widely studied, knowledge regarding novel high-performance fibers such as PBO (poly(p-phenylene-2,6-benzobisoxazole)) remains limited, particularly with respect to potential strength reductions caused by geometric curvature. The aim of this study was to experimentally investigate the tensile mechanical properties of PBO-reinforced concrete. First, axial tensile tests were conducted to characterize the tensile behavior of the composite material and to evaluate the effective utilization of the PBO textile within the concrete matrix. These tests revealed typical failure mechanisms of carbon-reinforced concrete, but also a significant reduction in tensile strength compared to the pure yarn tensile strength. Subsequently, the tensile load-bearing behavior in curved component configurations was investigated to evaluate the influence of geometric curvature. The results show that there is no reduction in tensile strength due to curvature, which indicates favorable structural response of the highly flexible and geometrically adaptable PBO reinforcement. The comparison of axial and curved tensile strength shows that PBO textiles can achieve high utilization within concrete matrices even in curved configurations. These results highlight the potential of PBO-reinforced concrete as a strengthening system, especially when geometric curvature of the reinforcement is unavoidable.