Experimental research on reinforced concrete columns strengthened by bfrps under eccentric compression

The method of strengthening reinforced concrete structure with carbon fiber reinforced plastic (CFRP) is a new developing one in the field of civil engineering. The technology of retrofit using CFRP has been studied thoroughly by many scholars. However, less research work is aimed to load-carrying performance of columns strengthened by basalt fiber reinforced plastic sheet (BFRPS). Especially, experimental research on concrete columns strengthened by BFRPS under eccentric compression, which is valuable in project, is almost blank. Based on the tests of 6 eccentrically loaded confined concrete columns, the ultimate bearing capacity of the columns and the load-strain curves of longitudinal bars, steel stirrups, concrete and BFRPS have been measured in detail; the strength capacity, stiffness of the columns strengthened with BFRPS have been researched; the ductility, distribution of cracks and failure modes of retrofitted columns have been analyzed; the influence on the basis of different strengthening modes are also discussed at last. Experimental results show that: columns strengthened by the combined action of the longitudinal and the transverse straps of BFRPS gain more significant effects. The strength capacity of columns has been enhanced largely and crack widths are reduced and distributed uniformly, and the ductility of columns improves significantly under the same condition.