Experiment and Comparison on Shear Behavior of New Type Rodlike Polypropylene Fiber Reinforced Concrete

Abstract:

Aiming at the rodlike polypropylene fiber introduced from Japan and common steel fiber used in the shotcrete lining,this paper presents a study on changes of the shear strength of concrete with different matrix strength and fiber content through the shear test of 72 specimens divided into 18 groups.The results show that as the fibre content increases,the shear strength of the rodlike polypropylene fiber concrete increases at first and then drops down,while the shear strength of the steel fiber concrete increases.When the fibre content is within 0.5%,the shear strength increase of the rodlike polypropylene fiber concrete is close to that of the steel fiber concrete,when the fibre content exceeds 0.5%,the shear strength increase of the rodlike polypropylene fiber concrete is lower than that of the steel fiber concrete.The fibers improve more on the shear strength of the C30 concrete than the C50 concrete.Finally,fitting formulas on the shear strength of the fiber concrete are gained based on the theory of regression analysis,and the calculation results of the formulas are accordant with the experimental results well.

Key words:tunnel engineering; fiber reinforced concrete; shear test; shear strength; rodlike polypropylene fiber