Fiber-Reinforced, High-Performance Mortars With High-Alumina Cement And Silica Fume

Mortar mixtures with high-alumina cement, silica fume, acrylic superplasticizer and metallic microfibers (length/diameter in mm = 13/0.18) were fabricated.The following properties were measured: water-cementitious material ratio at a given workability; compressive and flexural strength; fracture energy; thermal stability at high temperatures (50 degreesC). The 28-day compressive strength is very high (about 150 MPa) when 5-10% of silica fume is used independently of the superplasticizer dosage (0.5-1%). The thermal stability is very high even in the absence of silica fume when the water-cementitious material ratio is as low as 0.16. The fracture energy appears to be very high but it changes erratically from (20,000 to 30,000 Joule/m(2)) and it is related to both the silica fume content and the superplasticizer dosage.