scholarly journals Ideal supplementary cementing material – Metakaolin: A review

2020 ◽  
Vol 11 (1) ◽  
pp. 58-65
Author(s):  
G. Lizia Thankam ◽  
Neelakantan Thurvas Renganathan
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Mineral Admixture ◽  
Homogeneous Material ◽  
Interfacial Zone ◽  
Supplementary Cementing Materials ◽  
Pozzolanic Material ◽  
Efficient Packing ◽  
Cementing Material ◽  
Zone Microstructure

AbstractThough being an ancient trend, usage of the homogeneous material cement in the construction industry is steadily getting eradicated with the springing up of supplementary cementing materials (SCM). Metakaolin is an imminent mineral admixture extracted from the mineral ore kaolinite, which enhances the interfacial zone by more efficient packing at the cement paste-aggregate particle interface, thus reducing the bleeding and producing a denser, more homogeneous transition zone microstructure. This paper depicts the various repercussions of the pozzolanic material metakaolin in the fresh and hardened properties of concrete when replaced with cement in finite amount. Also, it states the behavior of high-performance concrete and self-compacting concrete with metakaolin.

The Mechanism of Mineral Admixture in Cement Hydration

2012 ◽  
Vol 450-451 ◽  
pp. 1528-1531
Author(s):  
Mei Li Zhao
Keyword(s):  
Cement Paste ◽  
High Performance ◽  
Cement Hydration ◽  
High Performance Concrete ◽  
Cement Mortar ◽  
Sem Analysis ◽  
Mineral Admixture ◽  
Hydration Mechanism ◽  
Curing Period ◽  
Durability Performance

The mineral admixture is one of the indispensable materials for ordinary high-performance concrete. In this paper, the pure cement paste and cement paste replacing by mineral admixture were tested by cement mortar. The SEM analysis of pure cement paste and mineral admixture paste after curing period of 7 days and 28 days.From the picture of SEM after the period of 7 days and 28 days,the cement hydration mechanism was suspected.It could be used for explanating the physical performance and durability performance of the high perfromance concrete with mineral admixture.

scholarly journals Ground Glass Pozzolan in Conventional, High, and Ultra-High Performance Concrete

2018 ◽  
Vol 149 ◽  
pp. 01005 ◽  
Author(s):  
Arezki Tagnit-Hamou ◽  
Ablam Zidol ◽  
Nancy Soliman ◽  
Joris Deschamps ◽  
Ahmed Omran
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Ground Glass ◽  
Strengthening Effect ◽  
Ultra High Performance Concrete ◽  
Conventional Concrete ◽  
Supplementary Cementitious Material ◽  
Pozzolanic Material ◽  
And Performance

Ground-glass pozzolan (G) obtained by grinding the mixed-waste glass to same fineness of cement can act as a supplementary-cementitious material (SCM), given that it is an amorphous and a pozzolanic material. The G showed promising performances in different concrete types such as conventional concrete (CC), high-performance concrete (HPC), and ultra-high performance concrete (UHPC). The current paper reports on the characteristics and performance of G in these concrete types. The use of G provides several advantages (technological, economical, and environmental). It reduces the production cost of concrete and decrease the carbon footprint of a traditional concrete structures. The rheology of fresh concrete can be improved due to the replacement of cement by non-absorptive glass particles. Strength and rigidity improvements in the concrete containing G are due to the fact that glass particles act as inclusions having a very high strength and elastic modulus that have a strengthening effect on the overall hardened matrix.

Boundary Element Analysis of Accelerated Chloride Diffusion in High Performance Concrete

2013 ◽  
Vol 842 ◽  
pp. 151-155
Author(s):  
Yi Wang ◽  
Wo Cheng Hang ◽  
Lu Feng Yang ◽  
Zheng Chen
Keyword(s):  
Diffusion Coefficient ◽  
Boundary Element ◽  
High Performance ◽  
Numerical Solutions ◽  
High Performance Concrete ◽  
Chloride Concentration ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Chloride Diffusion ◽  
Chloride Permeability

This paper aims to analyze accelerated chloride diffusion in high performance concrete (HPC) blended with mineral admixture by using boundary element method (BEM). Rapid chloride permeability test (RCPT) was employed and executed. The experiment proves that the highest resistance to chloride permeability can be acquired in the quaternary-blended concretes (ordinary portland cement + fly ash + blast furnace slag + silica fume). A chloride diffusion BEM model was established according to the diffusion coefficient calculated from the charge passed. The numerical solutions agree with experiments well. It can be inferred that the acceleration degree of RCPT is not the same in different mix proportion. Besides, the results also suggest that the low chloride permeability of the concretes with mineral admixtures may be attributed to the lower diffusion coefficient and the lower surface chloride concentration.

Study on Interfacial Properties of Ultra-High Performance Concrete Containing Steel Slag Powder and Fly Ash

2011 ◽  
Vol 194-196 ◽  
pp. 956-960 ◽  
Author(s):  
Yan Zhou Peng ◽  
Kai Chen ◽  
Shu Guang Hu
Keyword(s):  
Fly Ash ◽  
Bond Strength ◽  
High Performance ◽  
Steel Fiber ◽  
High Performance Concrete ◽  
Steel Slag ◽  
Interfacial Zone ◽  
Ultra High Performance Concrete ◽  
Slag Powder ◽  
Steel Slag Powder

The interfacial properties of reactive powder concretes (RPCs), other known as ultra-high performance concrete (UHPC), containing steel slag powder and ultra fine fly ash are studied in this paper. The microstrctural characterization of interfacial transition zones (ITZs), including the aggregate-cement paste interfacial zone and the steel fiber-paste interfacial zone, is investigated by SEM. The microhardness of the aggregate-paste ITZ and the steel slag-paste ITZ is studied and the bond strength of steel fiber in matrix is tested through fiber pullout tests. The results indicate that the microhardness of the steel slag-paste ITZ is slightly higher than that of the aggregate-paste ITZ, which implies the advantage of the substitution of quartz powder with steel slag powder in preparation of RPCs to some degrees. Moreover, the hardness of these two ITZs is higher than that of the hardened paste. A certain amount of hydration products has been observed exsiting on the surface of steel fiber by SEM and the bond strength of steel fiber-martix is up to 9.3MPa. These interfical properties are definitely critical to obtain high performance of UHPCs containing steel slag powder and fly ash.

Analysis of Microstructure of Interfacial Transition Zone (ITZ) in Recycled Aggregate Concrete

2013 ◽  
Vol 811 ◽  
pp. 249-253 ◽  
Author(s):  
Wei Li ◽  
Hai Ying Zhang
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Interfacial Structure ◽  
Recycled Aggregate ◽  
Concrete Aggregate ◽  
Interfacial Zone ◽  
Aggregate Concrete ◽  
Mortar Strength

Experiments on influence of species of aggregate and mixing method on interfacial zone in recycled aggregate concrete were investigated. SEM observations revealed that a recycle normal-strength concrete aggregate consist of loose and porous interfacial structure, whereas a recycled high performance concrete (HPC) aggregate and a triple mixing (TM) consist mainly of dense hydrates. Various admixtures on ITZ was produced that consumed CH in the pore, modified attached cement mortar. Strength of recycled concrete was explained by interaction between cements paste and recycled aggregate. The result verified that the relatively dense pore structure of the recycled concrete benefit to development of mechanical properties.

Early Age Cracking Characteristic of Concrete with Compound Admixtures

2013 ◽  
Vol 325-326 ◽  
pp. 71-74
Author(s):  
Yun Feng Li ◽  
Dong Sheng Zhang ◽  
Li Xu
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
High Performance ◽  
High Performance Concrete ◽  
Steel Slag ◽  
Test Method ◽  
Mineral Admixture ◽  
Early Age ◽  
Furnace Slag

The shrinkage cracking of concrete plays an important role to the accelerated deterioration and shortening the service life of concrete structures. The mineral admixture will be a perfect component of high performance concrete and its utilization will be a valuable resource for recycling. Early age cracking characteristics of concrete with compound admixtures, such as steel slag, blast furnace slag, fly ash, are studied in this paper using plate test method. The better anti-cracking performance of concrete will be realized when blast furnace slag replacing cement at 30%, steel slag and fly ash as the equal mixture components replacing cement at 30%, three kinds of admixtures replacing cement at 30% under the proper proportion.

Value Analysis and Properties Investigation of High Performance Rice Husk Ash Concrete

2013 ◽  
Vol 773 ◽  
pp. 293-297 ◽  
Author(s):  
Lee Kuo Lin ◽  
Wei Sheng Wu ◽  
Hubert Lee
Keyword(s):  
Rice Husk ◽  
High Performance ◽  
Rice Husk Ash ◽  
High Performance Concrete ◽  
Green Building ◽  
Global Village ◽  
Value Analysis ◽  
Carbon Reduction ◽  
Pozzolanic Material ◽  
Strength And Durability

During recent years, the Taiwan government launches issues of green building , sustainable engineering , carbon reduction and etc. , to promote balance construction and environment ecology. One of the most important materials in those engineering issues is cement which is used widely in construction industry. Cement emits 0.85 tons of carbon dioxide (CO2) for each ton of cement used in average. This not only causes the waste of energy but also againsts the conception of environmental protection. This research uses the rice husk ash (RHA) which people always regards as the waste material as a pozzolanic material to replace part of cement to make high performance concrete (HPC). Then makes the value analysis and properties investigation for HPC. Based on this research, rice husk (RH) will contain lots of silicon dioxide (SiO2) after burning into RHA. If use RHA to replace part of cement, it can get appropriate properties of compressive strength and durability. More important is that by replacing part of cement, it not only will reduce the emission of CO2 and save money but also reach the goal of global village protection on earth.

scholarly journals Rheological Properties Of Self-Consolidating Concrete Incorporating Natural And Industrial Pozzolans

2021 ◽  
Author(s):  
Asaad Mousa
Keyword(s):  
Rheological Properties ◽  
Yield Stress ◽  
Silica Fume ◽  
High Performance ◽  
High Performance Concrete ◽  
Cost Effective ◽  
Sustainable Construction ◽  
Self Consolidating Concrete ◽  
Supplementary Cementing Materials ◽  
Passing Ability

Self-consolidation concrete (SCC) is the latest version of high performance concrete with excellent workability and high resistance to segregation and bleeding. The main objective of this project is to study the rheological properties of SCC incorporating natural and industrial pozzolans (silica fume and metakaolin, repectively) as supplementary cementing materials (SCMs). Use of such pozzolanic materials in the development of environmentally friendly and cost effective SCC can lead to sustainable construction. In this project eleven SCC mixtures are developed by incorporating different percentages of silica fume (SF) and metakaolin (MK) as replacement of cement. However, the water cement ratio of all SCC mixtures are optimized so that all mixtures satisfied the requirements of SCC in terms of fresh properties such as workability, stability, passing ability, bleeding and segregation resistance. This study particularly concentrates on evaluation of the rheological properties such as viscosity and yield stress of developed silica fume and metakaolin based SCC mixtures. The influence of SF and MK dosages on viscosity and yield stress of SCC mixtures are evaluated. Correlations among fresh and rheological properties are developed and critically reviewed to make recommendations.

scholarly journals Optimum Dose of Binary Admixtures in Self Compacting Concrete

2019 ◽  
Vol 9 (1) ◽  
pp. 103-108
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Optimum Dose ◽  
Replacement Level ◽  
Self Compacting Concrete ◽  
Pozzolanic Material ◽  
Time Flow ◽  
Day By Day

Self Compacting Concrete (SCC) is a high performance concrete and is becoming popular day by day in the field of construction. Generally, the quantity of binder is more in SCC than the normal concrete. The application of pozzolanic material is found successful in such type of concrete. Generally, Ordinary Portland Cement (OPC) is replaced with Fly Ash (FA). In this paper, the results of an experimental programme to evaluate the performance of SCC are presented and optimum dose of binary admixture was found. For the determination of the optimum dose, concrete cubes of 100mm sizes were cast. The replacement level of OPC by FA was varied as- 5, 10, 15 and 20%, by mass. The OPC was also replaced separately by Metakaolin (MK) - 5, 10, 15 and 20%, by mass. Further, the OPC was replaced by the binary admixture (FA+MK). The workability and strength of SCC of grade M25 (Referral concrete- RC) and the concrete using the binary admixtures were studied. All SCC mixes were tested for workability as recommended by EFNARC i.e. Slump flow, T50 time flow, V-funnel, L-box, U-box and J-ring. The workability of SCC mix increases with FA and decreases gradually as MK content is increased. The optimum replacement level of OPC by binary admixture is 25% (FA-15% + MK-10%) with respect to compressive strength. The water absorption of cubes was also examined. It is concluded that a high strength and economical SCC could be developed by incorporation of FA and MK.

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