Study on mechanical properties of seawater sea-sand coral aggregate concrete-filled BFRP tubular arches

Abstract

In this paper, a novel arch-shaped BFRP tube with longitudinal BFRP bars pre-bonded on the inner wall is proposed and fabricated. It can provide strength in both circumferential and longitudinal directions and is suitable for the rapid construction of arch bridges in island environments by filling with seawater sea-sand coral aggregate concrete (SWCC) in situ. Ten SWCC-filled BFRP tubular arches were fabricated and tested under monotonic loading. Test variables include the wall thickness of the BFRP tube, the radius angles of the arch, and with or without pre-bonded BFRP bars. Test results showed that the failure modes of arches without BFRP bars were bending failure under the loading point. The ultimate bearing capacities were increased by 33.1% and 71.7% as the wall thickness increased from 2 mm to 3 mm and 4 mm, respectively. The failure modes of arches containing pre-bonded BFRP bars were bending-shear failure close to the loading plate. The ultimate bearing capacity of arches, which containing BFRP bars, with a wall thickness of 2 mm, 3 mm, and 4 mm increased by 215%, 248%, and 189%, respectively, compared with the specimens without BFRP bars. The integrity and ultimate bearing capacities of arches decreased with the increase of the radius angle and their failure modes exhibited obvious brittle damage characteristics. The proposed new type of arch has good prospects for application in the marine environment.