Effects of Mineral Admixture on the Paste Fluidity and Mortar Strength Development of High Chloride Cement

Â Concrete is the most extensively used construction material around the world and its properties have been undergoing changes through technological advancements. Varieties of concrete have been developed to enhance the different properties of concrete. An investigation in to the potential use of partial replacement of mineral admixture in high performance concrete (HPC) has carried out. The engineering properties of fresh and hardenedconcrete are obtained by conducting test on slump, vee-bee, compaction factor and compressive strength, flexural strength, spilt tensile strength and modulus of elasticity, in this project partial replacement of cement bymetakaolin and rice husk ash been used for varying replacement of 0+0%, 5+105, 7.5+10%,10+10%,5+12.5%, 10+12.5%, 5+15%, 7.5+15%,Â and 10+15%for high strength, workability and also an eco-friendly by less emission of co2. It has been concluded that strength development of concrete blended with metakaolin and rice hush ash was enhanced. It was found that in 7.5% replacement of metakaolin and 12.5% replacement of rice husk ash appear to be the optimum replacement which exhibited more strength. This investigation has proved that the MK and RHA concrete can be used as structural concrete at suitable replacement percentage.Â

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Study on the Effect of Curing Condition on the Performance of FBC Ash

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.549.687 ◽

2012 ◽

Vol 549 ◽

pp. 687-690

Author(s):

Tian Ding ◽

Yuan Ming Song ◽

Ai Zhi Cao ◽

Yu Xia Zha ◽

Jin Hui Yin

Keyword(s):

Portland Cement ◽

Linear Expansion ◽

Expansion Ratio ◽

Cement Clinker ◽

Strength Development ◽

Curing Conditions ◽

Mortar Strength ◽

Portland Cement Clinker ◽

Cementitious System ◽

Curing Condition

The cementitious system containing FBC ash is usually associated with volume expansion when cured in the normal temperature, due to its relatively high SO3 content. This paper presents a further study on the effect of different curing conditions on the flexural and compressive strength of FBC ash-Portland cement clinker mortar and linear expansion ratio of FBC ash-Portland cement clinker paste. The results show that autoclaved curing is more beneficial to increasing mortar strength in early days than standard curing, but with slow strength development in later period. Moreover, autoclaved curing could decrease the expansion of FBC ash greatly. This study confirms that the expansion of FBC ash can be significantly inhibited by autoclaved curing.

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Methodological Approaches to 3D Pore Structure Exploration in Cementitious Materials

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.517.305 ◽

2012 ◽

Vol 517 ◽

pp. 305-314 ◽

Cited By ~ 3

Author(s):

Piet Stroeven ◽

L.B Nghi Le ◽

Huan He

Keyword(s):

Image Analysis ◽

Pore Structure ◽

Blended Cement ◽

Cementitious Materials ◽

Quantitative Image Analysis ◽

Mineral Admixture ◽

Strength Development ◽

Cement Production ◽

Quantitative Image ◽

3D Information

About 6% of global CO2 emissions are due to cement production. Blending of Portland cement with a significant fraction of mineral admixture could therefore be instrumental in reducing such emissions. Use of an admixture of vegetable origin such as rice husk as will additionally contribute to waste management and its incineration produces energy. This paper will stress the importance of properly designing such blends. Preferably gap-graded concepts should be employed, since blending efficiency in terms of strength development is promoted as shown in earlier publications. The paper therefore only briefly covers these aspects. Assessment of this blending concept on durability of cementitious materials constitutes a far more complicated problem. This requires careful porosimetry. Mostly, this problem is approached by MIP or by quantitative image analysis. Both can provide 3D information, although that of MIP is generally significantly biased. Quantitative image analysis is however time-consuming and laborious, and thus expensive. Moreover, it does not provide information on continuity of pores. Present day computer facilities offer therefore a better alternative. When using a proper DEM system, the concrete can be simulated in a realistic way. The paper describes new methods for investigating the pore structure in virtual concrete and presents some data on pure cement and blended cement. Differences will have impact on durability risks.

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Properties of Concrete with High-Volume Limestone Powder under Low Temperature Conditions

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.675.296 ◽

2013 ◽

Vol 675 ◽

pp. 296-301

Author(s):

Shao Min Song ◽

Wen Zhong Bao ◽

Wen Xin Zhao ◽

Dong Min Jin

Keyword(s):

Fly Ash ◽

Low Temperature ◽

High Volume ◽

Sulfate Solution ◽

Active Role ◽

Mineral Admixture ◽

Limestone Powder ◽

Strength Development ◽

Binder Ratio ◽

Water Binder Ratio

This paper studies the effects of high-volume composite mineral admixture made of limestone powder and low-quality fly ash on the properties of concrete,and studies the form of attack of cement-based material made of limestone powder at low water-binder ratio under low-temperature sulfate environment.Through experiments, this paper makes clear the workability of fresh concrete and analyzes the law of strength development of concrete. The experimental results indicate that the concrete with high-volume limestone powder as composite mineral admixture has good fresh properties; due to low water consumption per unit volume, medium-and-high-strength concrete can be prepared. As new type concrete mineral admixture, the composite mineral admixture made of limestone powder and low-quality fly ash will play an active role in the sustainable development of concrete industry. After the specimen with the water-binder ratio of less than 0.4 and the limestone powder volume of greater than 20% is soaked in 10% magnesium sulfate solution at low temperature at the age of 200d, gypsum attack-led destruction is caused to the concrete test cube, without thaumasite sulfate attack.

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Mechanism on Activation of Coal Gangue Admixture

Advances in Civil Engineering ◽

10.1155/2021/5436482 ◽

2021 ◽

Vol 2021 ◽

pp. 1-17

Author(s):

Jixi Chen ◽

Xiao Guan ◽

Mengyu Zhu ◽

Jie Gao

Keyword(s):

Evaluation Method ◽

Particle Surface ◽

Waste Utilization ◽

Coal Gangue ◽

Mineral Admixture ◽

Activation Mechanism ◽

Activation Effect ◽

Mortar Strength ◽

Chemical Activator ◽

Secondary Hydration

Coal gangue, an industrial waste, is rich in silicon and aluminum phase and may be used as a mineral admixture in concrete after moderately stimulating activity, allowing for efficient solid waste utilization. This study used a mortar strength and activity evaluation method to investigate single or compound activation methods to find the optimum activation method of coal gangue. FLIR, XRD, and SEM were used to investigate the activation mechanism of different modes, providing a theoretical foundation for the study of coal gangue as a concrete admixture. Results showed that mechanical ball milling, microwave, and chemical activator could activate coal gangue, and the composite activation effect was the best. The fineness of the coal gangue powder was more than 300 mesh, according to the optimal compounding method. Accordingly, the particle surface was smooth, the internal defects were reduced, and the microwave irradiation temperature was 700°C–800°C, causing the coal gangue particles to form a bonding surface and gradually agglutinate and densify. Meanwhile, the layered structure of kaolin minerals was destroyed, and a significant amount of glassy active SiO2 and Al2O3 was produced, enhancing the gel ability and activity of coal gangue. Finally, 8% Ca(OH)2 was added in the production of mortar specimens, which increased the alkalinity of the slurry, stimulated the rapid cracking and secondary hydration of the coal gangue, and enhanced the strength of mortar. At this time, the activity rate of coal gangue powder reached the highest, which was 90.5%.

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Concrete with organic mineral admixture based on fine grinding cooper slag

Vestnik MGSU ◽

10.22227/1997-0935.2016.2.86-97 ◽

2016 ◽

pp. 86-97

Author(s):

Aleksey Vladimirovich Kravtsov ◽

Sergey Valer’evich Tsybakin ◽

Ekaterina Alekseevna Vinogradova ◽

Lidiya Mikhaylovna Borodina

Keyword(s):

Normal Condition ◽

Federal District ◽

Industrial Wastes ◽

Mineral Admixture ◽

Copper Production ◽

Strength Development ◽

Cement Stone ◽

Fine Grinding ◽

Organic Mineral ◽

Concrete Production

The problem of applying copper manufacturing wastes locating in Chelyabinsk region as a component of organic mineral admixture for concrete with industrial wastes production is considered in this article. Also, organic mineral admixture consisting of superplasticizers, based on esters with carboxyl groups, has not yet been sufficiently studied due to the diversity of species and the complexity of chemical structure. This trend is current for today’s science because of the growing rates and scales of building production, in particular, concrete works. Using new complex admixtures processed of industrial by-products showed their effectiveness. Copper slag dumps located in Urals federal district haven’t been widely used in building production or in other industrial production up to the present time. Efficient utilization of copper production waste materials will help to solve the ecological problems in most regions of Russia. The structure formation period of cement stone with organic mineral admixture, based on fine grinding cooper slag and superplasticizer, is also studied in the article. The thermal variation diagram of concrete mixture with organic mineral admixture during 22 hours of hardening under normal condition are shown and the results of ultrasound of concrete forming structure period during 6 hours of hardening are presented in this article. The strength development process diagram of concrete with organic mineral admixture during 28 days of hardening under normal condition and the research results of the compressive strength of concrete samples are also presented. The obtained characteristics confirm the prospects of applying this kind of non-ferrous metallurgy wastes in the concrete. Also, the obtained results allow us to conclude the significant advantages of using this kind of complex admixture for concrete production with different purpose and in different fields of application.

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Properties of Concrete with High-Volume Limestone Powder as Composite Mineral Admixture

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.193-194.351 ◽

2012 ◽

Vol 193-194 ◽

pp. 351-359

Author(s):

Shao Min Song ◽

Xiao Lun Wang ◽

Lin Wang

Keyword(s):

Fly Ash ◽

Fresh Concrete ◽

High Strength ◽

High Volume ◽

Active Role ◽

Mineral Admixture ◽

Limestone Powder ◽

Strength Development ◽

The Sustainable Development ◽

New Type

This paper studies the effects of high-volume composite mineral admixture made of limestone powder and low-quality fly ash on the properties of concrete. Through experiments, this paper makes clear the workability of fresh concrete and analyzes the law of strength development of concrete. The experimental results indicate that the concrete with high-volume limestone powder as composite mineral admixture has good fresh properties; due to low water consumption per unit volume, medium-and-high-strength concrete can be prepared. As new type concrete mineral admixture, the composite mineral admixture made of limestone powder and low-quality fly ash will play an active role in the sustainable development of concrete industry.

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Influence of Steel Slag-Superfine Blast Furnace Slag Composite Mineral Admixture on the Properties of Mortar and Concrete

Advances in Civil Engineering ◽

10.1155/2021/9983019 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Zhenguo Liu ◽

Zongxian Huang

Keyword(s):

Blast Furnace ◽

Blast Furnace Slag ◽

Steel Slag ◽

Autogenous Shrinkage ◽

Mineral Admixture ◽

Strength Development ◽

Adiabatic Temperature Rise ◽

Solid Ratio ◽

Composite Mixture ◽

Furnace Slag

A composite mineral admixture was prepared by steel slag and superfine blast furnace slag. The influence of superfine blast furnace slag content of the composite mixture on the mortar and concrete was investigated. The results show that the composite mineral admixture may decrease the strength of concrete at the early age but improve the strength development over time. Increasing the content of superfine blast furnace slag can reduce the degradation of the early strength. The reduction of the autogenous shrinkage and adiabatic temperature rise is significant when the composite mineral admixture is added. The reduction is more obvious when the water-to-solid ratio (w/s) is low. The results show that with steel slag and superfine blast furnace slag playing as complementary parts in the composite mineral admixture, it can be used as an effective substitute of cement.

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