scholarly journals INFLUENCE OF SILICA COLLOID ON RHEOLOGY OF CEMENT PASTE WITH SUPERPLASTICIZER

2017 ◽  
Vol 25 (1) ◽  
pp. 73-80
Author(s):  
T.H. Chuong ◽  
P.V. Nga
Keyword(s):  
Experimental Data ◽  
Rheological Property ◽  
Silica Fume ◽  
Cement Paste ◽  
Rheological Behavior ◽  
Concrete Mixture ◽  
Silica Colloid ◽  
Binder Ratio ◽  
High Silica ◽  
Water Binder Ratio

Information of rheological behavior of binder paste is important for proportioning high slump concrete mixture at low water to cement ratios. This paper presents experimental data on the rheological property of silica colloid incorporated binder paste using naphthalene based and polycarboxylate based superplasticizer, compared to that of silica fume incorporated binder paste. Experimental data showed that silica colloid incorporated binder is compatible to tested superplasticizers in the all investigated range of silica colloid content, whereas the pastes incorporated with high silica fume content (over 10%) indicated incompatibility, especially to naphthalene based superplasticizer. There was also found out saturated content of superplasticizer corresponding to every kind of binder and water-binder ratio, with and without set retarding admixture. 

Study on the Effect of Fly Ash or Silica Fume to Hydration Heat of Cement

2011 ◽  
Vol 250-253 ◽  
pp. 4001-4004 ◽  
Author(s):  
Li Guo Ma ◽  
Yun Sheng Zhang
Keyword(s):  
Fly Ash ◽  
Binary System ◽  
Silica Fume ◽  
Cement Paste ◽  
Heat Evolution ◽  
Hydration Heat ◽  
Dormant Period ◽  
Binder Ratio ◽  
Isothermal Calorimeter ◽  
Water Binder Ratio

The hydration heat evolution process is studied on the pure cement paste, the cement- fly ash binary system and the cement- silica fume binary system with water binder ratio(w/b) of 0.53, 0.35 and 0.23 by using isothermal calorimeter(TAM Air). The fly ash replacement in the cement-fly ash binary system is 10%, 30% and 50% respectively. The silica fume replacement in cement-silica fume binary system is 4%, 8% and 12% respectively. The experiments results indicate that w/b had great impact on the hydration heat evolution and the hydration heat decrease with the decrease in w/b. The addition of fly ash greatly decrease the exothermic rate and total hydration heat. The addition of silica fume shortens dormant period and increases the peak exothermic rate, but reduces the total hydration heat.

The Research of Mixture Ratio Factors on the Concrete Consumption Norm

2013 ◽  
Vol 724-725 ◽  
pp. 1580-1584
Author(s):  
Ming Ru Zhou ◽  
Zheng Bo Li ◽  
Qiong Fei Shen ◽  
Zhong Yu Guo
Keyword(s):  
Raw Material ◽  
Concrete Mixture ◽  
Mixture Ratio ◽  
Percentage Unit ◽  
Decisive Influence ◽  
Concrete Mix ◽  
Binder Ratio ◽  
Water Binder Ratio

Concrete valuation work is mainly on the composition of concrete raw material pricing, different concrete mixture ratio has decisive influence on the valuation. Concrete mix is influenced by many parameters, such as water-binder ratio, sand percentage, unit water and so on. The mixture ratio is the purpose to research the inner relationship between concrete parameters.In the preparation of the consumption of the concrete norm, analysis to the reasonable mix can not only make valuation work accords with the specification requirements, but meet the practice.

Effect of Heat Treatment on Properties of Portland Cement Pastes: Determination through Ultra-Microhardness Test

2015 ◽  
Vol 820 ◽  
pp. 492-496
Author(s):  
D.C.S. Garcia ◽  
Roberto Braga Figueiredo ◽  
Maria Teresa Paulino Aguilar
Keyword(s):  
Heat Treatment ◽  
Portland Cement ◽  
Optical Microscopy ◽  
Silica Fume ◽  
Ordinary Portland Cement ◽  
Cement Pastes ◽  
Microhardness Test ◽  
Material Hardness ◽  
Binder Ratio ◽  
Water Binder Ratio

The aim of this paper was to investigate the influence of heat treatment on hardness evolution of cement pastes containing silica fume. The specimens were prepared with Ordinary Portland Cement, water/binder ratio of 0,40 and 25% wt. silica fume. The specimens were cast at room temperatures and after 24 hours, they were placed in a furnace for 24 hours, with heat regimes of 100°C, 200°C and 300°C and then submitted to the ultra-microhardness test. The microstructure was analyzed using optical microscopy. The results showed that the silica fume prevents the production of calcium hydroxide and the heat treatment increases the material hardness.

Influence of superplasticizer dosage on the viscosity of cement paste with low water-binder ratio

2017 ◽  
Vol 149 ◽  
pp. 359-366 ◽  
Author(s):  
Jianzhong Liu ◽  
Kejin Wang ◽  
Qianqian Zhang ◽  
Fangyu Han ◽  
Jianfang Sha ◽  
...  
Keyword(s):  
Cement Paste ◽  
Binder Ratio ◽  
Water Binder Ratio

scholarly journals Influence of Concrete Mixture Composition on Acid Resistance of Concrete: A Review

2021 ◽  
Author(s):  
Chinnu Mariam Ninan ◽  
K P Ramaswamy ◽  
R Sajeeb
Keyword(s):  
Acid Resistance ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Concrete Mixture ◽  
Mixture Composition ◽  
Soluble Salts ◽  
Acid Attack ◽  
Related Factors ◽  
Binder Ratio ◽  
Water Binder Ratio

Cementitious materials are highly susceptible to rapid and severe degradation by a wide range of acids that are found immensely in ground water, sewage systems, industrial effluents, acid rain etc. which may cause microstructure deterioration. The factors influencing acid attack is generally categorised as material related factors and test related factors. Material related factors can be either related to acid solution or concrete mixture composition. Composition of concrete mixture greatly impacts the acid resistance of concrete. Factors related to composition of concrete mixture are type of cement, type and proportion of binders, water binder ratio, aggregate binder ratio and mineralogical nature of the aggregates. Even though the type of cement influences acid attack, the magnitude of variation is negligible. Consumption of calcium hydroxide and refinement of pore structure makes the use of supplementary cementitious materials favourable for acid resistance. Decrease in water binder ratio and increase in aggregate binder ratio reduces the porosity of concrete and thereby improves the acid resistance of concrete. Calcareous aggregates are preferred for concretes exposed to acids having less soluble salts and not preferred for acids forming soluble salts. This paper highlights the influence of composition of concrete mixture on acid resistance of concrete. A proper formulation of concrete is expected to enhance its acid resistance.

scholarly journals Use of condensed silica fume for making high-strength, self-consolidating concrete

2000 ◽  
Vol 27 (4) ◽  
pp. 620-627 ◽  
Author(s):  
A KH Kwan
Keyword(s):  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Concrete Strength ◽  
High Strength ◽  
Self Consolidating Concrete ◽  
Concrete Mix ◽  
Binder Ratio ◽  
Condensed Silica Fume ◽  
Water Binder Ratio

A high concrete strength can be achieved by lowering the water/binder ratio and a high workability by adding a higher dosage of superplasticizer. However, a high-performance concrete with both high strength and high workability cannot be produced by just these means because lowering the water/binder ratio leads to lower workability and there is a limit to the increase in workability that can be attained by adding superplasticizer. To produce a high-strength, high-workability concrete, the concrete strength needs to be increased without lowering the water/binder ratio. This can be done by adding condensed silica fume. In this study, a series of trial mixing aimed at developing high-strength, self-consolidating concrete (mean cube strength >80 MPa and needs no compaction for consolidation) was carried out. Several mixes suitable for making such high-performance concrete have been developed and it was found that the addition of condensed silica fume may, under favourable conditions, increase not only the strength but also the workability of the concrete mix. Based on the trial mix results, charts for the design of high-strength, high-workability concrete mixes made of the studied constituents are presented.Key words: condensed silica fume, high-strength concrete, self-consolidating concrete.

scholarly journals Effect of Silica Fume on the Rheological Properties of Cement Paste with Ultra-Low Water Binder Ratio

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 554
Author(s):  
Juan He ◽  
Congmi Cheng ◽  
Xiaofen Zhu ◽  
Xiaosen Li
Keyword(s):  
Hysteresis Loop ◽  
Rheological Properties ◽  
Yield Stress ◽  
Silica Fume ◽  
Plastic Viscosity ◽  
Rheological Parameters ◽  
Loop Area ◽  
Binder Ratio ◽  
Hysteresis Loop Area ◽  
Water Binder Ratio

The effect of silica fume on the rheological properties of a cement–silica fume–high range water reducer–water mixture with ultra-low water binder ratio (CSHWM) was studied. The results indicate that the W/B ratio and silica fume content have different effects on the rheological parameters, including the yield stress, plastic viscosity, and hysteresis loop area. The shear-thickening influence of CSHWM decreased with the increased silica fume content. When the silica fume content increased from 0% to 35%, the mixture with W/B ratio of 0.19 and 0.23 changed from a dilatant fluid to a Newtonian fluid, and then to a pseudoplastic fluid. When the silica fume content was less than 15%, the yield stress was close to 0. With the increase of silica fume content, the yield stress increased rapidly. The plastic viscosity and hysteresis loop area decreased slightly with the addition of a small amount of silica fume, but increased significantly with the continuous increase of silica fume. Compared with the Bingham and modified Bingham models, the Herschel–Buckley model is more applicable for this CSHWM.

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