Strengthening effect analysis of lightweight aggregate concrete restrained by steel tube

Based the test results of lightweight aggregate concrete-filled steel stub columns with square section and circular section, strengthening effect of lightweight aggregate concrete restrained by steel tube was studied. Various parameters influence to strengthening coefficient of lightweight aggregate concrete was analyzed. Different concrete and steel stub section were compared. The results show that the strengthening coefficient increases as the lightweight aggregate concrete strength and width (diameter) to thickness ratio increase, and as the steel ratio and confining coefficient decrease. The strengthening coefficient of lightweight aggregate concrete is higher than normal aggregate concrete´s. And the square one is also higher than the circular one.