Dispersing Silica Fume in Cementitious Materials by Silane Copolymerized Polycarboxylate Superplasticizer: On the Role of Dispersion Effectiveness as a Function of Silane Concentration

2021 ◽  
Author(s):  
Jian Huang ◽  
Yuting Zhao ◽  
Xin Wang ◽  
Mesfin Manuka ◽  
Hailong Hu ◽  
...  
Keyword(s):  
Silica Fume ◽  
Cementitious Materials ◽  
Polycarboxylate Superplasticizer ◽  
Silane Concentration

Packing Density Improvement for Improving Strength of Cement Paste

2019 ◽  
Vol 943 ◽  
pp. 124-128 ◽  
Author(s):  
Jian Jian Chen ◽  
Hong Niao Chen ◽  
Gu Li
Keyword(s):  
Silica Fume ◽  
Packing Density ◽  
Water Film ◽  
High Strength ◽  
Cementitious Materials ◽  
Maximum Strength ◽  
Depth Analysis ◽  
Fuel Ash ◽  
Pulverized Fuel ◽  
Pulverized Fuel Ash

To design a mix for high-strength concrete is not easy, one of the methods is to improve the packing density of the cementitious materials. To study the effect of packing density on strength, a comprehensive research program using superfine pulverized fuel ash and silica fume was carried out. Results showed that a high superfine pulverized fuel ash and silica fume ratios could result in a lower optimum W/CM ratio for maximum strength. Depth analysis illustrated that the optimum water film thickness for maximum strength is always at around 0.01 to 0.05 μm, regardless of the SPFA and SF ratios.

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.

scholarly journals Study of Hydration and Microstructure of Mortar Containing Coral Sand Powder Blended with SCMs

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4248
Author(s):  
Xingxing Li ◽  
Ying Ma ◽  
Xiaodong Shen ◽  
Ya Zhong ◽  
Yuwei Li
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Silica Fume ◽  
Dilution Effect ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Limestone Powder ◽  
Chemical Effect ◽  
Granulated Blast Furnace Slag ◽  
Coral Sand

The utilization of coral waste is an economical way of using concrete in coastal and offshore constructions. Coral waste with more than 96% CaCO3 can be ground to fines and combined with supplementary cementitious materials (SCMs) such as fly ash, silica fume, granulated blast furnace slag in replacing Portland cement to promote the properties of cement concrete. The effects of coral sand powder (CSP) compared to limestone powder (LSP) blended with SCMs on hydration and microstructure of mortar were investigated. The result shows CSP has higher activity than LSP when participating in the chemical reaction. The chemical effect among CSP, SCMs, and ordinary Portland cement (OPC) results in the appearance of the third hydration peak, facilitating the production of carboaluminate. CSP-SCMs mortar has smaller interconnected pores on account of the porous character of CSP as well as the filler and chemical effect. The dilution effect of CSP leads to the reduction of compressive strength of OPC-CSP and OPC-CSP-SCMs mortars. The synergic effects of CSP with slag and silica fume facilitate the development of compressive strength and lead to a compacted isolation and transfer zone (ITZ) in mortar.

scholarly journals The Compressive Strength of High-Performance Concrete and Ultrahigh-Performance

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
E. H. Kadri ◽  
S. Aggoun ◽  
S. Kenai ◽  
A. Kaci
Keyword(s):  
Experimental Data ◽  
Compressive Strength ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Cementitious Materials ◽  
Strength Gain ◽  
Proposed Model ◽  
Partial Cement Replacement ◽  
Better Than

The compressive strength of silica fume concretes was investigated at low water-cementitious materials ratios with a naphthalene sulphonate superplasticizer. The results show that partial cement replacement up to 20% produce, higher compressive strengths than control concretes, nevertheless the strength gain is less than 15%. In this paper we propose a model to evaluate the compressive strength of silica fume concrete at any time. The model is related to the water-cementitious materials and silica-cement ratios. Taking into account the author's and other researchers’ experimental data, the accuracy of the proposed model is better than 5%.

Unsaturated ion diffusion in cementitious materials – The effect of slag and silica fume

2018 ◽  
Vol 108 ◽  
pp. 31-37 ◽  
Author(s):  
Nilla Olsson ◽  
Barbara Lothenbach ◽  
Véronique Baroghel-Bouny ◽  
Lars-Olof Nilsson
Keyword(s):  
Silica Fume ◽  
Cementitious Materials ◽  
Ion Diffusion

scholarly journals Sustainable low-carbon binders and concretes

2020 ◽  
Vol 166 ◽  
pp. 06007
Author(s):  
Myroslav Sanytsky ◽  
Tetiana Kropyvnytska ◽  
Stanislav Fic ◽  
Hanna Ivashchyshyn
Keyword(s):  
Activity Index ◽  
Chemical Properties ◽  
High Volume ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Cement Matrix ◽  
Low Carbon ◽  
Blended Cements ◽  
Physical And Chemical

Sustainable development depends on a consistency of interests, social, ecological and economic, and that the interests are evaluated in a balanced manner. In order to reduce CO2 emissions, the conception of decreasing clinker factor and increasing the role of supplementary cementitious materials (SCMs) in the cementitious materials has high economical and environmental efficiency. The performance of clinkerefficient blended cements with supplementary cementitious materials were examined. The influence of superfine zeolite with increased surface energy on the physical and chemical properties of low-carbon blended cements is shown. Increasing the dispersion of cementitious materials contributes to the growth of their strength activity index due to compaction of cement matrix and pozzolanic reactions in unclincker part. In consequence of the early structure formation and the directed formation of the microstructure of the cement matrix is solving the problem of obtaining clinker-efficient concretes. Shown that low-carbon blended cements with high volume of SCMs are suitable, in principle, for producing structural concretes.

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