Study On Concrete Of C80Prestressed High-Strength Concrete Pipe Pile

Various superplasticizers and mineral admixtures were usually used in producingC80PHC pipe pile. The selected admixtures should have good adaptability, low slumploss, and the distinctly enhancive effect on steam curing and autoclave concrete.Different mineral admixtures have different influences on the strength of C80PHC pipepile. This paper improves the production technology of aminosulfonic acid basedsuperplasticizer and naphthalene sulphonated superplasticizer based on the traditionalproduction technology, and developed the compound technology of these twosuperplasticizers in the production process of C80PHC pipe pile. The effects andmicro-mechanism of fly ash, slag powder and silica flour on the steam curing andautoclave strength of concrete were also investigated. Furthermore, a non-autoclavedmineral admixture was developed.The results show: this special admixture has better adaptability and lower slumploss so that adapt to the molding requirements of pipe pile and has well enhanced effecton strength. According to the C80PHC pipe pile production process of steam curingbefore autoclave，the enhanced effect of slag powder and silica flour are better than flyash on strength. Only blending fly ash or slag powder can’t satisfy the strengthrequirement of C80. Only blending silica flour or mixing slag powder and silica flourcan both satisfy the strength requirement of C80. The strength of concrete withnon-autoclaved mineral admixtures can reach86.8MPa after second steam curing.