Silica fume

About: Silica fume is a research topic. Over the lifetime, 10177 publications have been published within this topic receiving 173857 citations.

Utilization of silica fume in concrete: Review of durability properties

Abstract: With increased environmental awareness and its potential hazardous effects, utilization of industrial byproducts has become an attractive alternative to disposal. Silica fume (SF), which is byproduct of the smelting process in the silicon and ferrosilicon industry. Silica fume is very effective in the design and development of high strength high performance concrete. This paper covers the physical, chemical properties of silica fume, and its reaction mechanism. It deals with the effect of silica fume on the permeability, freezing and thawing resistance, corrosion, sulfate resistance, carbonation, and alkali-aggregate resistance of concrete.

Mechanical properties of reactive powder concrete containing high volumes of ground granulated blast furnace slag

Abstract: The mechanical properties (flexural strength, compressive strength, toughness and fracture energy) of steel microfiber reinforced reactive powder concrete (RPC) were investigated under different curing conditions (standard, autoclave and steam curing). Portland cement was replaced with ground granulated blast furnace slag (GGBFS) at 20%, 40% and 60%. Sintered bauxite, granite and quartz were used as aggregates in different series. The compressive strength of high volume GGBFS RPC was over 250 MPa after autoclaving. When an external pressure was applied during setting and hardening stages, compressive strength reached up to 400 MPa. The amount of silica fume can be decreased with increasing amount of GGBFS. SEM micrographs revealed the tobermorite after autoclave curing.

Effects of elevated temperature exposure on heating characteristics, spalling, and residual properties of high performance concrete

Abstract: This paper describes results of NIST's experimental program that focuses on effects of elevated temperature exposure on residual mechanical properties of HPC. Residual mechanical properties were measured by heating the 102×204 mm cylinders to steady state thermal conditions at a target temperature, and loading them to failure after the specimens had cooled to room temperature. The test specimens were made of four HPC mixtures with water-to-cementitious material ratio (w/cm) ranging from 0.22 to 0.57, and room-temperature compressive strength at testing ranges from 51 MPa to 93 MPa. Two of the four HPC mixtures contained silica fume. The specimens were heated to a maximum core temperature of 450°C, at a heating rate of 5°C/min. Experimental results indicate that HPCs with higher original strength (lowerw/cm) and with silica fume retain more residual strength after elevated temperature exposure than those with lower original strength (higherw/cm) and without silica fume. The differences in modulus of elasticity are less significant. However, the potential for explosive spalling increased in HPC specimens with lowerw/cm and silica fume. An examination of the specimens' heating characteristics indicate that the HPC mixtures which experienced explosive spalling had a more restrictive process of capillary pore and chemically bound water loss than those which did not experience spalling.