STUDY ON THE INFLUENCE OF COARSE AGGREGATE TYPES ON THE BONDING PROPERTIES OF HIGH-STRENGTH CONCRETE-FILLED STEEL TUBE
Main article
Abstract
This paper presents the results on the influence of coarse aggregate types on the bonding properties of high strength concrete filled steel tube. In order to study the difference of interface bonding properties between square and circle steel tube high-strength concrete with different coarse aggregate types, a total of 18 specimens were designed and prepared for steel tube push-out tests. The variation parameters of concrete strength grade, coarse aggregate type and steel tube section shape are mainly considered for the tests. Through the experiments, the failure patterns of samples are observed, analyzed and recorded. The load-displacement curve and characteristic point parameters are sketched and analyzed too. Whereas the factors affecting the failure process and bonding properties of the concrete-filled steel samples are studied. The results show that for square specimens, the ultimate bond strength and residual bond strength of natural crushed stone specimens are the largest, and the residual bond strength of crushed pebble specimens is the smallest. For circle specimens, the ultimate bond strength of natural crushed stone specimens is the highest, and that of crushed pebble specimens is the least. Under the condition that the bond area is close to the same (the difference of bond area of specimens is less than 10%), the ultimate bond strength of the square specimen is mostly higher than
that of the circle specimen, and the residual bond strength of the circle specimen is higher than that of the square specimen. Thus, it can be concluded that the ultimate bond strength and residual bond strength are vary depending on the concrete strength grade and coarse aggregate types.
