MECHANICAL PROPERTIES O F U LTRHIGH P ERFORMANCE F IBER R EINFORCED C ONCRETE

Ultrahigh performance fiber reinforced concrete (UHPFRC), as a new class of concrete, has attracted a lot of attention in recent years. This type of concrete with a compressive strength of more than 150 MPa, has high packing density, very low permeability, superior durability and very high abrasion and corrosion resistanc e. Small steel fibers, used in UHPFRC, cause the increase of flexural strength and ductility. In the present study, it has been tried to produce ultrahigh performance fiber reinforced concrete using the most suitable available materials in Egypt: such as P ortland cement, silica fume, quartz powder, steel fibers, superplasticizer, fine quartz sand, and fine crushed dolomite (max nominal size 4.75 mm). For all test specimens, a w/c of 0.18 was applied. Also, the effects of adding different amounts of quartz and silica fume on main properties of UHPC have been investigated. The results show that using the available materials together with steel fibers and conducting normal treatment, UHPFRC with compressive strength up to 1 51 MPa and flexural strength of 33.75 MPa was produced