MECHANICAL-PROPERTIES AND DURABILITY OF POLYPROPYLENE FIBER-REINFORCED HIGH-VOLUME FLY-ASH CONCRETE FOR SHOTCRETE APPLICATIONS

Investigations at CANMET have led to the development of polypropylene fiber reinforced, high-volume fly ash concrete for shotcreting rock outcrops. This type of concrete has a very low water-to-cementitious material ratio, fly ash content greater than 50 percent of the cementitious material, and contents of fibers up to 5 kg/m3 of concrete. The workability of the concrete is maintained by the use of high dosages of superplasticizers. This paper presents the results of CANMET investigations dealing with the development of this type of concrete. The test results show that polypropylene fiber reinforced, high-volume fly ash concrete has satisfactory work-ability and strength characteristics. It also has very low permeability, low drying shrinkage, adequate ductility, and toughness characteristics.