STUDY ON THE BOND PERFORMANCE BETWEEN CFRP BARS AND ALKALI-ACTIVATED SLAG SEAWATER AND SEA SAND CONCRETE

To study the bond performance between CFRP bars and alkali-activated slag seawater and sea sand concrete, pull-out tests were carried out for 200 specimens with different types of bars (CFRP bars and steel bars), different bond lengths (2.5 d, 5 d, 7.5 d, 10 d and 15 d) and four types of concrete including fresh water and river sand alkali-activated slag concrete (FRASC), fresh water and sea sand alkali-activated slag concrete (FSASC), seawater and river sand alkali-activated slag concrete (SRASC) and seawater and sea sand alkali-activated slag concrete (SSASC). In the test, all specimens with CFRP bars and bonding lengths of 15 d exhibited splitting failure of the concrete, whereas those with steel bars and bond lengths of 10 d and 15 d exhibited tensile fracture of the steel bars. The loading stage for the specimens with CFRP bars and bond lengths of 2.5 d has a second peak because the external bundle band of the CFRP bars was snapped. The bond-slip curve can be divided into five stages, that is, the micro slip stage, slide stage, stripping stage, softening stage and residual stage.