Experimental Study on the Complete Tensile Stress-Deformation Curve of Fully Graded Concrete

Concrete is a type of quasi-brittle material with high compressive strength and low tensile strength. To obtain the complete tensile stress-deformation curve of massive concrete specimens, a specially designed loading machine is proposed with a pair of hydraulic oil dampers parallel to the direction of the tensile loading. The dampers were designed with valves to modify the stiffness of the loading machine, enhancing the stiffness of the machine before the applied stress reaches 90% of the ultimate stress of the concrete. Several experiments were conducted with the proposed loading machine on prism-shaped specimens (size: 1350 mmx 450 mm x 450 mm), and the stress-deformation curves and mechanical parameters of the concrete were obtained. Finally, an empirical formula is presented and compared with the experimental results.