APPLICATION OF POLYPROPYLENE FIBER IN CONCRETE USED IN HIGH SPEED RAILWAY

摘要

Polyethylene fiber is a kind of macromolecule material widely used in every walk of life. In this paper, polyethylene fiber in concrete material used in high speed railway was introduced. Early drying shrinkage characteristic of polyethylene fiber concrete, workability of polyethylene fiber concrete and durability of polyethylene fiber were investigated. Results show that compared to blank concrete, slump of polypropylene fiber concrete decreases, but addition of proper superplasticizer and fly ash can improve polypropylene fiber concrete slump greatly. Polypropylene fiber concrete has the performance of low drying shrinkage. In this paper, different types of polypropylene fiber take on almost the same effects on drying shrinkage. Addition of fly ash takes on unapparent effect on drying shrinkage of polypropylene fiber concrete. For low strength concrete with high w/b, mixed polypropylene fiber into concrete can improve chloride ion attack resistance, but for high strength concrete with low w/c, mixed polypropylene fiber decreases chloride ion attack resistance.