Different mineral admixtures of Indian metakaolin, Iranian silica fume and nanosilica were used to produce high performance mortars. Two different sands types with grain size of 0.015-4mm were mixed with type II Portland cement, polycarboxylate superplasticizer,mineral admixture with 650kg/m3 cement content and water/cement ratio of 0.35. Different amount of cement was replaced by metakaolin or...

The tensile strength of cement paste was increased by 56% and the modulus and ductility were increased by 39% by using silane-treated carbon fibers and silane-treated silica fume, relative to the values for cement paste with as-received carbon fibers and as-received silica fume. Silane treatment of fibers and silica fume contributed about equally to the strengthening. Silane treatment of fibers...

This study focuses on the effect of the amount of silica fume addition and volume fraction of steel fiber on the engineering properties of cementitious materials. Test variables include dosage of silica fume (5% and 10%), water/cement ratio (0.35 and 0.55) and steel fiber dosage (0.5%, 1.0% and 2.0%). The experimental results included: compressive strength, direct tensile strength, splitting te...

a r t i c l e i n f o Keywords: 1 H NMR (B) Silica fume (D) C–S–H composition (B) Density (B) 1 H NMR has been used to characterise white Portland cement paste incorporating 10 wt.% of silica fume. Samples were measured sealed throughout the hydration without sample drying. Paste compositions and C–S–H characteristics are calculated based on 1 H NMR signal intensities and relaxation analysis. T...

The new Concrete Society Publication, Cementitious Materials, CSTR74, covers the effects of cementitious materials blast furnace slag (GGBS), fly ash (FA), limestone fines and silica fume (microsilica) on the properties of concrete. This paper focuses on the effects of silica fume on all the main properties of concrete in the fresh and hardened state as defined in the publication.

Surface treatment of silica fume with sulfuric acid prior to incorporation in a cement matrix resulted in composites exhibiting increases in tensile strength by 12%, tensile modulus by 72%, tensile ductility by 57%, abrasion resistance by 20%, loss tangent by 30–80%, flexural storage modulus by 80–120%, and flexural loss modulus by 160–300%, relative to the values obtained by using as-received ...

Silica fume has been largely used in concrete in recent decades due to its effect on improvement of strength and durability of concrete. On the other hand, attention has been recently paid to the use of limestone powder as a substitute for part of cement in concrete, basically because of its low price and its positive effect on the durability of concrete. The aim of the current study is the i...

The production of ordinary Portland cement (OPC) as the most expensive constituent of concrete is associated with destructive environmental effects and significant energy consumption. Thus, the use of supplementary cementitious materials such as Natural or synthetic pozzolans is a fundamental solution that affects the kinetics of hydration of cementitious materials. In this article, to evaluate...

Silica fume has been largely used in concrete in recent decades due to its effect on improvement of strength and &#10durability of concrete. On the other hand, attention has been recently paid to the use of limestone powder as a substitute for part of cement in concrete, basically because of its low price and its positive effect on the durability of concrete. The aim of the current study is the...