Analysis of the damping behavior and microstructure of cement matrix with silane-treated silica fume

2006 ◽  
Vol 21 (2) ◽  
pp. 1-5 ◽  
Author(s):  
Ou Jinping ◽  
Liu Tiejun ◽  
Li Jiahe
Keyword(s):  
Silica Fume ◽  
Cement Matrix ◽  
Damping Behavior

Research on Properties of Low Grade Cement-Based Composite Materials Modified by Silica Fume

2012 ◽  
Vol 174-177 ◽  
pp. 751-756
Author(s):  
Zi Fang Xu ◽  
Ming Xu Zhang ◽  
Jin Hua Li
Keyword(s):  
Silica Fume ◽  
Mechanical Performance ◽  
Raw Materials ◽  
Cement Matrix ◽  
Hardened Cement ◽  
Low Grade ◽  
X Ray ◽  
Matrix Microstructure ◽  
Nano Powder ◽  
Strength And Durability

In order to notably improve the mechanical properties and durability of low-grade cement-based material, superfine silica fume was used to modify the cement-based composite based on special perfomance and effects of nano powder. The mechanical performance and durability were investigated.Then the phase compositions,microstructure and morphologies of as-received cement-based composite were studied by X-ray Diffractometer、TGA-DTA and SEM. The results show that： the best formula of raw materials is 1:1:0.025:0.015, and hydration can be accelerated and increasing of hydration products is observed after modification. In the hardened cement matrix, microstructure is very compacted and C-S-H gel forms densed structure, so the structure defect is notably reduced. This means that both strength and durability of cement-based composite are notably improved by the addition of superfine silica fume.

Effects of sand and silica fume on the vibration damping behavior of cement

1998 ◽  
Vol 28 (10) ◽  
pp. 1353-1356 ◽  
Author(s):  
Y. Wang ◽  
D.D.L. Chung
Keyword(s):  
Silica Fume ◽  
Vibration Damping ◽  
Damping Behavior

Cropped Steel Fiber Reinforced Chemically Bonded Ceramic (CBC) Composites

1987 ◽  
Vol 114 ◽  
Author(s):  
Sean Wise ◽  
Kevan Jones ◽  
Claudio Herzfeld ◽  
David D. Double
Keyword(s):  
Silica Fume ◽  
Steel Fiber ◽  
High Strength ◽  
Cement Matrix ◽  
Metal Fiber ◽  
Morphological Form ◽  
The Matrix ◽  
Compressive And Flexural Strengths ◽  
Equivalent Properties ◽  
Very High

ABSTRACTVery high strength castable chemically bonded ceramic (CBC) materials have been prepared which consist of finely chopped steel fibers and steel aggregate in a silica modified portland cement matrix. This paper examines the effect of metal fiber addition on compressive and flexural strengths. The overall chemistry of the matrix is held constant but the morphological form of silica used and the cure conditions are altered to examine their effect. Compressive strengths in excess of 500 MPa and flexural strengths in excess of 80 MPa can be obtained.It is found that flexural strength increases proportionally with fiber content over the range of 0 to 10% by volume. Compressive strengths are not affected. Use of silica fume in the mixes produces higher strengths at low temperatures than mixes which contain only crystalline silica. High temperature curing/drying (400°C), which produces the highest strengths, produces equivalent properties for formulations with and without silica fume. Higher water/cement ratios are found to reduce compressive strengths but have relatively little effect on the flexural properties.

Improvements on Mechanical Property and Microstructure of Cementitious Composite Incorporated with Silica Fume and Carbon Nanotube

2019 ◽  
Vol 298 ◽  
pp. 167-171
Author(s):  
Gu Yue Han ◽  
Jian Lin Luo
Keyword(s):  
Compressive Strength ◽  
Carbon Nanotube ◽  
Silica Fume ◽  
Cementitious Materials ◽  
Filler Loading ◽  
Cement Matrix ◽  
Ultrasonic Dispersion ◽  
Integrated Network ◽  
Positive Effects ◽  
Ultrafine Silica

Nano-size fillers (ultrafine silica fume (USF) or/and multi-walled carbon nanotube (MWCT)) were incorporated into cement matrix to fabricate nano-fillers reinforced cementitious materials (NFRCs) with surfactant ultrasonic dispersion and subsequently mix cast process. The flexural and compressive strengths of four groups NFRCs with varied nano-filler loading were comprehensively investigated. Results show, there are positive effects on the flexural and compressive strength of NFRCs with nano-fillers loading, especially when USF and MWCT are incorporated simultaneously, and the correspondent maximal flexural and compressive strength can increase by above 17%, 28% with respect to the baseline, respectively. The pozzolan infilling effect of USF and the crack-bridging effect of dispersed MWCT result in the dense and integrated network microstructures of cured NFRC.

Investigation and Improvement on the Mechanical Property of Cement Mortar

2012 ◽  
Vol 253-255 ◽  
pp. 482-488
Author(s):  
Hai Bo Zhang ◽  
Xue Mao Guan ◽  
Hai Tao Shang
Keyword(s):  
Mechanical Property ◽  
Contact Angle ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cement Mortar ◽  
Hydrophobic Surface ◽  
Cement Matrix ◽  
Weak Interface ◽  
Rubber Surface

This paper examined the mechanical property of rubber mortars with different amount of rubber granules addition and the influence of fly ash, slag and silica fume. The increase of rubber granules results in the decrease in compressive and flexural strength of rubber mortar, but increases the ratio of flexural to compressive strength. The fly ash, slag and silica fume are useful for improving the mechanical property of mortar. The examined contact angle of water against rubber is 99.5°, which suggests the rubber surface is hydrophobic, and the hydrophobic surface interprets the weak interface between rubber and cement matrix.

Diffusivity in Cement-Silica Fume Based Materials: Experimental and Computer Modeling Results on Mortars

2016 ◽  
Vol 711 ◽  
pp. 1098-1104
Author(s):  
Z. Bajja ◽  
W. Dridi ◽  
A. Darquennes ◽  
R. Bennacer
Keyword(s):  
Silica Fume ◽  
Diffusion Coefficients ◽  
Volume Fraction ◽  
Transport Model ◽  
Input Parameter ◽  
Tritiated Water ◽  
Effective Diffusion ◽  
Nitrogen Adsorption ◽  
Cement Matrix ◽  
Biphasic Model

Silica fume cement (SFC) based materials are largely used as a containment barrier for nuclear waste management. The safety of this storage mode depends on the knowledge of the effective diffusion coefficients of such materials. This work proposes a combination of computer models able to estimate the diffusion coefficients of SFC pastes and mortars, from a single investigation of the microstructure by nitrogen adsorption. The approach used consists firstly in manufacturing SFC mortars by varying sand volume fraction from 30 to 65% while silica fume replacement and water to binder ratio were respectively set at 10% and 0.4. Nitrogen adsorption tests were then performed and collected data on C-S-H nature are introduced into a SFC pastes hydration model. The latter provides the mineral composition which is an input parameter in the multilayer transport model that estimates the effective diffusion coefficient (De) of cement pastes. For mortars, a 3D biphasic model (sand and cement matrix) was used to compute the (De) of mortars at different inclusion volume fractions. The numerical results were approved by comparison to experimental data obtained from tritiated water (HTO) diffusion tests performed on manufactured mortars.

Durability of Wood Shavel Composites with Environmental Friendly Based Binder

2015 ◽  
Vol 1119 ◽  
pp. 391-397
Author(s):  
Jul Endawati ◽  
Lilian Diasti
Keyword(s):  
Silica Fume ◽  
Bending Strength ◽  
High Volume ◽  
Cement Matrix ◽  
Thickness Swelling ◽  
Tropical Condition ◽  
Fiber Degradation ◽  
High Volume Fly Ash ◽  
Small Wood

The composite element of 20 mm in thickness were manufactured using high volume fly ash, silica fume as alternative hydraulic binders and Portland cement Type II. Pine wood shavel as by product of local small wood working industries were used as the composite filler. The elements were given in situ wet and dry treatment for 9 months. Visually there is no fiber degradation as a result of the interaction of the environment. The assessment were done to the elements bending strength and dimensional properties. Increase in MoRafter 180 days of exposure shown that mechanically, this degradation is not seen yet. The increment of MoR ( 213%) compare to that of 28 days might be affected by the formation of calcium hydroxide (CH) or ettringite in the transition zone. The use of pozzolan showed also a delay or minimize degradation of composites while improving the pore structure, and minimize the mineralization of the fiber bond with the cement matrix. The water absorption is 4,22% at 180 days, 7,94% at 120 days and 12,38% at 28 days, in line with the 68% decrease in Thickness Swelling (TS). This unoccured degradation could also be affected by the presence of silica fume in the binder matrix. After 270 days of exposure under tropical condition, the flexural strength started to decrease.

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