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 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.

Determination of free chloride in seawater cement paste with low water-binder ratio

2021 ◽  
Vol 124 ◽  
pp. 104217
Author(s):  
Yifan Zhao ◽  
Xiang Hu ◽  
Caijun Shi ◽  
Qiang Yuan ◽  
Deju Zhu
Keyword(s):  
Cement Paste ◽  
Free Chloride ◽  
Binder Ratio ◽  
Water Binder Ratio

scholarly journals The Rapid Chloride Migration Test in Assessing the Chloride Penetration Resistance of Normal and Lightweight Concrete

2021 ◽  
Vol 11 (16) ◽  
pp. 7251
Author(s):  
Jorge Pontes ◽  
José Alexandre Bogas ◽  
Sofia Real ◽  
André Silva
Keyword(s):  
Lightweight Concrete ◽  
Chloride Transport ◽  
Penetration Resistance ◽  
Chloride Penetration ◽  
Migration Test ◽  
Simple Method ◽  
Chloride Migration ◽  
Binder Ratio ◽  
Chloride Penetration Resistance ◽  
Water Binder Ratio

Chloride-induced corrosion has been one of the main causes of reinforced concrete deterioration. One of the most used methods in assessing the chloride penetration resistance of concrete is the rapid chloride migration test (RCMT). This is an expeditious and simple method but may not be representative of the chloride transport behaviour of concrete in real environment. Other methods, like immersion (IT) and wetting–drying tests (WDT), allow for a more accurate approach to reality, but are laborious and very time-consuming. This paper aims to analyse the capacity of RCMT in assessing the chloride penetration resistance of common concrete produced with different types of aggregate (normal and lightweight) and paste composition (variable type of binder and water/binder ratio). To this end, the RCMT results were compared with those obtained from the same concretes under long-term IT and WDT. A reasonable correlation between the RCMT and diffusion tests was found, when slow-reactive supplementary materials or porous lightweight aggregates surrounded by weak pastes were not considered. A poorer correlation was found when concrete was exposed under wetting–drying conditions. Nevertheless, the RCMT was able to sort concretes in different classes of chloride penetration resistance under distinct exposure conditions, regardless of the type of aggregate and water/binder ratio.

Research on Electrical Double Percolation of Carbon Black-Filled Cement-Based Composites

2011 ◽  
Vol 311-313 ◽  
pp. 201-204
Author(s):  
Hong Zhong Ru ◽  
Ran Ran Zhao
Keyword(s):  
Carbon Black ◽  
Cement Paste ◽  
Volume Fraction ◽  
Carbon Black Particle ◽  
Carbon Black Content ◽  
Percolation Behavior ◽  
Key Factor ◽  
Binder Ratio ◽  
Black Particle ◽  
Double Percolation

Electrical conductive carbon black-filled cement-based composites are significant as multifunctional structural materials. Double percolation in carbon black-filled cement-based composites involves both carbon black particle percolation and cement paste percolation, which has great effect on the resistivity of composites. Based on double percolation theory, the influences of sand-binder ratio and carbon black volume fraction on the resistivity of carbon black-filled cement-based composites are investigated. The results show that besides carbon black volume fraction, sand-binder ratio is a key factor affecting double percolation behavior in carbon black-filled cement-based composites. At a fixed carbon black content in overall mortar, with increasing sand-binder ratio, the cement paste percolation though aggregate phase increases due to high obstruction of aggregate but the carbon black particle percolation in cement paste decreases. This is because that the microstructure of aggregate is impenetrable so that the carbon black particles are limited in cement paste, that is, the carbon black content in paste is compacted and large amount of conductive paths are generated by lapped adjacent carbon black particles in paste. The double percolation in the electrical conduction in carbon black-filled cement-based composites is observed when the carbon black volume fraction is 7.5% and sand-binder ratio is 1.4, and its resistivity is only 3200 Ωcm, so that a sand-binder ratio of 1.4 and 7.5% carbon black volume fraction or more are recommended for attaining high conductivity with a compromise between workability and conductivity.

Effect of Fly Ash and Nano-CaCO3 on the Viscosity of Cement Paste

2013 ◽  
Vol 357-360 ◽  
pp. 968-971 ◽  
Author(s):  
Ren Juan Sun ◽  
Zhi Qin Zhao ◽  
Da Wei Huang ◽  
Gong Feng Xin ◽  
Shan Shan Wei ◽  
...  
Keyword(s):  
Fly Ash ◽  
Cement Paste ◽  
Bingham Model ◽  
Reduced Viscosity ◽  
Binder Ratio ◽  
Water To Binder Ratio

The effect of fly ash and nanoCaCO3 on the viscosity of pastes was studied. The rheological value of cement paste was determined by the rotation rheometer NXS-11B. In the study, five different dosages (0%, 20%, 30%, 40%, and 50%) of fly ash and three levels of nanoCaCO3, 0.5%, 1%, and 2.5%, were considered. Viscosity of the pastes, made with fly ash and nanoCaCO3 at a constant water-to-binder ratio of 0.35, were measured and analyzed. The results indicate that the pastes with fly ash or/and nanoCaCO3 still fit the Bingham model. The addition of fly ash reduced viscosity, however, the addition of nanoCaCO3 increased viscosity. The effect of nanoCaCO3 is more significantly than fly ash on viscosity.

Research in the Preparation of Paving Bricks with Construction Garbage

2013 ◽  
Vol 712-715 ◽  
pp. 917-920
Author(s):  
Lian Xi Wang ◽  
Guang Hui Pan ◽  
Fu Yong Li ◽  
Hai Ming Wang ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Experimental Results ◽  
Replacement Rate ◽  
Coarse Aggregates ◽  
Waste Concrete ◽  
Fine Aggregates ◽  
Binder Ratio ◽  
Water Binder Ratio

Construction garbage paving bricks were made of recycled coarse and fine aggregates which were prepared by the waste concrete. The influence of replacement rate of recycled coarse aggregates, water-binder ratio and excitation agent dosage on the compressive strength and flexural strength of construction garbage paving bricks were researched. The experimental results show that optimum replacement rate of recycled coarse aggregates, water-binder ratio and excitation agent dosage were 100%, 0.43 and 1.5% respectively. In this proportion, the 7d, 28d compressive strength of the products were 15.6MPa, 37.5MPa respectively, and the 7d, 28d flexural strength were 2.0MPa, 4.3MPa respectively, which fit the requirements of the Cc30 level of compressive strength and the Cf4.0 level of flexural strength involved in JCT 446-2000 "concrete pavers".

Application of New Concrete Materials in Channel Lining of the South-to-North Water Diversion Project

2011 ◽  
Vol 306-307 ◽  
pp. 942-945
Author(s):  
Wang Lin Li ◽  
Ying Te Li ◽  
Jian Ying Yu
Keyword(s):  
Crack Resistance ◽  
Compression Strength ◽  
Water Diversion ◽  
Concrete Lining ◽  
Manufactured Sand ◽  
Water Diversion Project ◽  
Binder Ratio ◽  
North Water ◽  
Water Binder Ratio ◽  
Channel Seepage

Concrete lining is commonly used in large channel project to fixup soil slope and prevent channel seepage. Concrete lining is a type of thin plates structure which should have the high compression strength, crack resistance and durability. Two new high performance concrete (HPC) are used in lining project of south main channel of Yellow River-crossing project in east-route of the South-to-North Water Diversion Project. One is flyash HPC with manufactured-sand and the other is HPC with cementitious capillary crystalline waterproofing material (CCCW); meanwhile, the mix proportion of flyash HPC with manufactured-sand and HPC with CCCW are recommended. For flyash HPC with manufactured-sand, the recommendatory water-binder ratio is 0.4 and the recommendatory flyash content is 30%. For HPC with CCCW, the recommendatory water-binder ratio is 0.48 and the recommendatory CCCW content is 1.5%.With the wide application of new HPC, the compression strength, crack resistance and durability of lining concrete are improved, channel seepage discharge is reduced and a large amount of natural building materials are saved.

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