Experimental study on the eccentrically compressive performance of square masonry columns repaired with UHPC jackets

Abstract

Ultra-high performance concrete (UHPC) is a new class of structural material with outstanding properties of high strength, excellent ductility, and durability, which has an extremely broad application field. To examine the rehabilitation potential of UHPC on the existing masonry structures, the mechanical behavior of square masonry columns strengthened with UHPC under eccentric loading was investigated in this paper. A total of six masonry columns with or without the confinement of UHPC jackets were axially and eccentrically loaded. The strengthening effectiveness of UHPC on masonry columns was explored in terms of failure mode, deformation capacity, and carrying capacity. The results showed that UHPC jacketing is a highly effective technique for strengthening masonry columns, significantly increasing both the load-carrying capacity and transverse deformability of eccentrically compressed masonry columns (up to 103.64% and 71.43%, respectively). Furthermore, the UHPC strengthening technique modified brittle damage in unconfined masonry columns. A theoretical calculation was carried out for determining the bearing capacity of masonry columns strengthened with UHPC under eccentric loading. The accuracy of the theoretical calculation method was verified by comparing the theoretical values with the experimental values. Thus, this study provides a theoretical basis for the practical application of masonry structures strengthened with UHPC.