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 Effect of quartz powder and mineral admixtures on the properties of high-performance concrete

Vestnik MGSU ◽  
2019 ◽  
pp. 102-117 ◽  
Author(s):  
Duc Vinh Quang Nguyen ◽  
Olga V. Aleksandrova ◽  
Yuriy M. Bazhenov
Keyword(s):  
Fly Ash ◽  
Silica Fume ◽  
Cement Paste ◽  
High Performance ◽  
High Performance Concrete ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Fine Aggregate ◽  
Quartz Powder ◽  
Additional Reduction

Introduction. This study focuses on the use of silica fume partially replacing cement with 0, 5, 7.5, 10, 12.5 and 30 % constant replacement of fly ash by weight of cement in concrete. Concrete is probably the most extensively used construction material in the world. But the conventional concrete is losing its uses with time and high-performance concrete (HPC) is taking that place. HPC has superior mechanical properties and durability to normal strength concrete. Because of, the microstructure of HPC is more homogeneous than that of normal concrete (NC) due to the physical and chemical contribution of the mineral admixtures as well as it is less porous due to reduced w/c ratio with the addition of a superplasticizer. The inclusion of additives helped in improving the properties of concrete mixes due to the additional reduction in porosity of cement paste and improving the particle packing in the interfacial transition zone (between cement paste and the aggregates).In this experimental investigation the behavior of HPC with silica fume and fly ash with and without quartz powder were studied. The water-binder ratio was kept 0.3 and 20 % quartz flour as partial replacement of fine aggregate for all cases. Materials and methods. Used materials in Vietnam, as follow, Sulfate-resisting Portland cement - PCSR40 (type V) of company Luks Cement (Vietnam) Limited was used in the work. Crushed granite of fraction 9.5…20 mm - as coarse aggregate, Natural sand from Huong river of 0.15…2.5 mm fraction with the fineness modulus of about 3.0 and quartz powder with an average particle size of 5…10 μm were used as fillers; Sika® Viscocrete®-151 is a superplasticizer based on a blend of 3rd generation PCE polymers was used as a plasticizing admixture. The flg ash from Pha Lai thermal power plant and Sika silica Sikacrete® PP1 (particle size < 0.1 μm) was used as a mineral active admixture. The study of strength and technological properties of high-performance concrete was performed by using standard methods. Results. Established by icate that, the workability and strength increase at a certain level and after that, they decline with further increase in the replacement level of silica fume is 12.5 %, on the basis of 30 % FA replacement, the incorporation of 10 % SF showed equivalent or higher mechanical properties and durability compared to the reference samples. Conclusions. HPC consists of mineral admixtures such as silica fume and fly ash use combine quartz powder and superplasticizer helped in improving the strength and durability of concrete mixes due to the additional reduction in porosity of cement paste and an improved interface between it and the aggregate. With 30 % fly ash is optimum dosage used to replacement of cement, incorporation 10 % SF (by weight) and combine of partial replacement of fine aggregate by 20 % quartz powder. On the other hand, a few mathematical equations can be used to derive the durability properties of concrete based on its compressive strength.

Modelling the Yield Stress of Fly-Ash Added Superplasticized Cement Paste at Different Temperatures Using Artificial Neural Network

2022 ◽  
Vol 1048 ◽  
pp. 366-375
Author(s):  
Pavan Chandrasekar ◽  
Anjala Nourin ◽  
Addepalli Sri Naga Bhushana Aravind Gupta ◽  
Bavineni Venkata Jyoshna ◽  
Dhanya Sathyan
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Fly Ash ◽  
Yield Stress ◽  
Cement Paste ◽  
Test Temperature ◽  
Fresh Concrete ◽  
Rheological Parameters ◽  
Different Temperatures ◽  
Artificial Neural

Abstract: Rheology is the science that concerns the flow of liquids, and the distortion of solids under an applied force. The study of the rheology of concrete determines the properties of fresh concrete. The rheological parameters are affected by temperature, stress conditions and several other factors. The main intention of this research is to model the rheological parameters of the fly ash incorporated cement with various types of superplasticizers exposed under different temperatures using an Artificial Neural Network. Test data were generated by performing rheological tests on cement paste at three distinct temperatures (15, 27, 35°C). Mixes were prepared using OPC, fly ash (15, 25, 35%) and superplasticizers of four different families. By conducting experiments, 252 data have been generated by modifying the combination of fly-ash, superplasticizer, and test temperature. Among the 252 data, 80% has been utilized for training and 20% is utilized for predicting the model’s accuracy. The input layer of the model consists of test temperature, the amount of fly ash replaced, cement and water content, and four different groups of superplasticizers. The cement paste’s yield stress was the output parameter of the model. The model generated data has been compared with the experimentally generated data to determine the accuracy of the model.Keywords: Rheology, Fly Ash, Superplasticizer, Temperature, ANN

Effect of Mineral Admixtures on Rheological Properties of Cement Paste

2014 ◽  
Vol 936 ◽  
pp. 1409-1413 ◽  
Author(s):  
Lin Chun Zhang ◽  
Ai Lian Zhang
Keyword(s):  
Fly Ash ◽  
Rheological Properties ◽  
Silica Fume ◽  
Cement Paste ◽  
Reducing Agent ◽  
Mineral Admixtures ◽  
Test Results ◽  
Optimal Ratio ◽  
Mix Proportion

The Marsh cone method and rotary viscosimeter are used to study the effect of mineral admixtures such as ultra-fine fly ash, ultra-fine slag, zeolite powder and silica fume on rheological properties of cement paste. Test results show that the optimal ratio of ultra-fine fly ash, ultra-fine slag, zeolite powder and silica fume are respectively 20%, 20%, 10% and 8%. And the optimized mix proportion is the composition of 8% silica fume and 12% slag. By using water reducing agent and mineral admixtures we could get the cement paste which has good liquidity and no bleeding.

scholarly journals A Study on the Relationships between Water Film Thickness, Fresh Properties, and Mechanical Properties of Cement Paste Containing Superfine Basalt Powder (SB)

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7592
Author(s):  
Hengrui Liu ◽  
Zhenghong Tian ◽  
Haoyue Fan
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Film Thickness ◽  
Cement Paste ◽  
Water Film ◽  
Mineral Admixtures ◽  
Rheological Parameters ◽  
Fresh Properties ◽  
Bleeding Rate ◽  
Water Film Thickness

In this paper, the effect of a newly developed superfine basalt powder (SB) on the fresh and mechanical properties of cement paste was studied. The concept of water film thickness (WFT) was cited to explain the influence of SB on fresh and mechanical properties and related mathematical model formulas were established. In addition, the relationship between the fresh properties and mechanical properties of paste was also explored. The results indicated that SB can improve the segregation resistance and cohesiveness. The maximum improvement rate relative to the control cement paste was 75.4% and 50.4%, respectively. The 5% SB and 10% SB reduced the fluidity in the range of 4.1–68.7% but increased the early and late compressive strength in the range of 1.2–25.7% compared to control cement paste under different water/cementitious materials (W/CM) ratios. However, the influence of 20% SB on fluidity and compressive strength was opposite to the above behavior, and the increase rate and decrease rate were 1.8–11.8% and 1.1–13.9% respectively. The WFT was the most important factor that determined the compressive strength, rheological parameters, and flow parameters of paste containing SB, while the substitute content of SB and WFT together determined the bleeding rate and cohesiveness. Among them, the correlation between bleeding rate and WFT increased with time. The empirical mathematical models between WFT, fresh properties, and compressive strength were established and verified by other mineral admixtures, which were successfully extended and applied to the entire field of cement-based materials

Rheological Characteristics and Methodology of Ice Cream: A Review

2020 ◽  
Vol 16 (5) ◽  
pp. 666-674
Author(s):  
Amir M. Mortazavian ◽  
Najme Kheynoor ◽  
Zahra Pilevar ◽  
Zhaleh Sheidaei ◽  
Samira Beikzadeh ◽  
...  
Keyword(s):  
Process Design ◽  
Flow Behavior ◽  
Ice Cream ◽  
Rheological Parameters ◽  
Rheological Characteristics ◽  
Rheological Analysis ◽  
Fundamental Information ◽  
Food Structure ◽  
Analytical Tools ◽  
Penetration Tests

The rheological analysis is important analytical tools used to obtain fundamental information about food structure. For instance, the properties of flow of liquid and semi-solidity are characterized by the consistency and flow behavior experiments as two important rheological parameters. The rheological parameters of foods are applied in quality control of the products and processing of food products such as energy input calculations, process design, equipment selection, and especially for deciding on heat exchangers and pumps. Steady flow behavior, oscillatory, and penetration tests are among commonly used parameters for evaluating rheological characteristics of ice cream. The purpose of this paper is to provide an overview of recent experiments and methods for measuring the rheological and texture properties of ice cream.

scholarly journals Effect of Mineral Admixtures on the Performance of Low-Quality Recycled Aggregate Concrete

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 596
Author(s):  
Yasuhiro Dosho
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Mineral Admixtures ◽  
Structural Concrete ◽  
Aggregate Concrete ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

To improve the application of low-quality aggregates in structural concrete, this study investigated the effect of multi-purpose mineral admixtures, such as fly ash and ground granulated blast-furnace slag, on the performance of concrete. Accordingly, the primary performance of low-quality recycled aggregate concrete could be improved by varying the replacement ratio of the recycled aggregate and using appropriate mineral admixtures such as fly ash and ground granulated blast-furnace slag. The results show the potential for the use of low-quality aggregate in structural concrete.

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