Resting time effect on the rheological behavior of cement paste in presence of superplasticizer

2021 ◽  
Vol 142 ◽  
pp. 106347
Author(s):  
Aida Margarita Ley-Hernández ◽  
Dimitri Feys
Keyword(s):  
Cement Paste ◽  
Rheological Behavior ◽  
Time Effect ◽  
Resting Time

Influence of Polycarboxylate Superplasticizer on Rheological Behavior in Cement Paste

2018 ◽  
Vol 33 (4) ◽  
pp. 932-937 ◽  
Author(s):  
Yan He ◽  
Xiong Zhang ◽  
Yaning Kong ◽  
Xiaofu Wang ◽  
Liangliang Shui ◽  
...  
Keyword(s):  
Cement Paste ◽  
Rheological Behavior ◽  
Polycarboxylate Superplasticizer

Rheological Behavior of Semisolid AlSi6Mg2 Alloy at Transient State

2012 ◽  
Vol 217-219 ◽  
pp. 369-372
Author(s):  
Li Ping Ju ◽  
Ying Wu ◽  
En Sheng Xu ◽  
Wei Wang ◽  
Hong Chao Luo
Keyword(s):  
Shear Rate ◽  
Rheological Behavior ◽  
Rheological Model ◽  
Transient State ◽  
External Flow ◽  
Flow Conditions ◽  
Agglomerate Size ◽  
Resting Time

In the present work, basing on the rheological model of Chen and Fan [1], the rheological behavior of AlSi6Mg2 alloy at transient state is investigated. It has been shown that the deagglomeration of particles is about two orders of magnitude faster than the agglomeration of them. The inequality of agglomeration rate and deagglomeration rate is thought as the origin of the thixotropy of SSMS. Subsequently, the similar trend of the variation of the viscosity and the average agglomerate size with shearing time and resting time shows that the microstructure of SSMS determines its rheological behavior, while the external flow conditions (such as shear rate, shearing time, etc) influence the viscosity by changing its microstructure. The present study predicts that the CF model can describe reliably the transient rheological behavior of AlSi6Mg2 alloy.

scholarly journals Rheological Behavior and Strength Characteristics of Cement Paste and Mortar with Fly Ash and GGBS Admixtures

2021 ◽  
Vol 13 (17) ◽  
pp. 9600
Author(s):  
V. Arularasi ◽  
P. Thamilselvi ◽  
Siva Avudaiappan ◽  
Erick I. Saavedra Flores ◽  
Mugahed Amran ◽  
...  
Keyword(s):  
Fly Ash ◽  
Cement Paste ◽  
Rheological Behavior ◽  
Shear Resistance ◽  
Ternary Mixtures ◽  
Strength Characteristics ◽  
Mineral Admixtures ◽  
Rheological Parameters ◽  
Rheological Characteristics ◽  
Flow Table

A cement paste or mortar is composed of a mineral skeleton with micron to millimeter-sized grains, surrounded by water filaments. The cohesion or shear resistance in the cement paste and mortar is caused by capillary forces of action. In the case of mortar mixes, there is friction between the particles. Therefore, the mortar mixture shows both friction between particles and cohesion, while the paste shows only cohesion, and the friction between particles is negligible. The property of the cement paste is greatly influenced by the rheological characteristics like cohesion and internal angle friction. It is also interesting that when studying the rheology of fresh concrete, the rheological behavior of cement paste and mortar has direct applicability. In this paper, the rheological characteristics of cement paste and mortar with and without mineral admixtures, that is, fly ash and ground granulated blast-furnace slag (GGBS), were studied. A cement mortar mix with a cement-to-sand ratio of 1:3 was investigated, including fly ash replacement from 10% to 40%, and GGBS from 10% to 70% of the weight of the cement. A suitable blend of fly ash, GGBS, and ordinary Portland cement (OPC) was also selected to determine rheological parameters. For mortar mixtures, the flow table was conducted for workability studies. The flexural and split tensile strength tests were conducted on various mortar mixtures for different curing times. The results indicate that in the presence of a mineral mixture of fly ash and GGBS, the rheological behavior of paste and mortar is similar. Compared with OPC-GGBS-based mixtures, both cement with fly ash and ternary mixtures show less shear resistance or impact resistance. The rheological behavior of the mortar also matches the rheological behavior in the flow table test. Therefore, it is easy to use the vane shear test equipment to conduct cohesion studies to understand the properties of cement paste and mortar using mineral admixtures. The strength results show that the long-term strength of GGBS-based mixtures and ternary mixed mixtures is better than that of fly-ash-based mixtures. For all mixtures, the strength characteristics are greatest at a w/b ratio of 0.6.

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. 

Consistency Assessment Method for Granular- Cement Paste Systems

2011 ◽  
Vol 295-297 ◽  
pp. 2178-2184
Author(s):  
H Hoornahad ◽  
E. A. B. Koenders
Keyword(s):  
Grain Size ◽  
Cement Paste ◽  
Rheological Behavior ◽  
Assessment Method ◽  
Experimental Results ◽  
Phase Model ◽  
Granular System ◽  
Sieve Analysis ◽  
Two Phase ◽  
Modelling Approach

Fresh granular-pasty materials are considered as an intermediate class between solid and fluid. These materials are capable of showing their rheological behavior which can be close to either a pasty or granular system depending on properties and proportion of ingredients in the mixture. Therefore, quantification of such dependencies is a crucial factor in order to be able to predict the performance of this type of material. In this study a two phase model is considered in which a mixture is decomposed into a paste and a granular phase. The relation between the aggregate grading and the consistency of the mixture has been investigated for a concrete in which the pasty behavior is dominant. It was found that if the volume and property of the paste that remains after filling the space in between the aggregates in compacted state is kept constant, the consistency of a mixture can be characterized by the number of aggregates corresponding to each grain size regarding the sieve analysis test. The paper presents a modelling approach and experimental results.

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