scholarly journals Mechanical Activation of Diabase and Its Effect on the Properties and Microstructure of Portland Cement

2022 ◽  
pp. e00868
Author(s):  
Abdul Vahap KORKMAZ
Keyword(s):  
Portland Cement ◽  
Mechanical Activation

scholarly journals Hydration study of mechanically activated mixtures of Portland cement and fly ash

2007 ◽  
Vol 72 (6) ◽  
pp. 591-604 ◽  
Author(s):  
Gordana Stefanovic ◽  
Ljubica Cojbasic ◽  
Zivko Sekulic ◽  
Srdjan Matijasevic
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Portland Cement ◽  
Mechanical Activation ◽  
Early Period ◽  
Negative Effects ◽  
Early Hydration ◽  
Cement Pastes ◽  
Dta And Tg ◽  
Low Activity

Fly ash (FA) can be used in cement mixtures with certain limitations. The problem of the mentioned mixtures lies in the insufficient activity of the particles of FA in the reactions which are important for the establishment of the mechanical characteristics of cement. This is particularly true for the hydration reactions. As a result of this, cement pastes formed by mixing ash and clinker have worse characteristics compared to those of pure Portland cement (PC), especially in the early period of setting. As is well known, FA can be a good solution for the neutralization of the negative effects generated due to the creation of free Ca(OH)2 during the hydration of PC, provided that the problems with the low activity of FAare overcome. For the experiments in this study, a mixture of Portland cement and fly ash was used, the content of ash in the mixture being 30 % and 50 %. Mechanical activation was performed in a vibrating ring mill. The goal of this study was to demonstrate, through experimental results, that during the mechanical activation of a PC and FA mixture, the components in the mixture which mostly affect the direction, rate and range of hydration reactions occurring in the mixture had been activated. The values of the compressive strength of the activated and non-activated mixtures and the changes of their specific surface area proved that during the grinding process, the mixture PC+FA had been mechanically activated. The highest increase of compressive strength was achieved in the early period of setting, which indicates an improvement in the early hydration of the mixture. XRD, DTA and TG analyses showed that the alite (C3S) and belite (C2S) from the PC and a part of the fly ash were activated. .

scholarly journals MICROSTRUCTURE HYDRATION PRODUCTS BINDING COMPOSITION OBTAINED IN THE VORTEX JET MILL

2017 ◽  
Vol 2 (3) ◽  
pp. 9-18 ◽  
Author(s):  
Золотых ◽  
Sergey Zolotykh ◽  
Сумской ◽  
Dmitriy Sumskoy ◽  
Загороднюк ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Portland Cement ◽  
Mechanical Activation ◽  
Cement Stone ◽  
Mineral Filler ◽  
Hydration Products ◽  
Dense Structure ◽  
Additional Support ◽  
Effective Use

Zagorodnuk L.H., Sumy D.A., Golden S.V., Kaneva E.V. MICROSTRUCTURE HYDRATION PRODUCTS BINDING COMPOSITION OBTAINED IN THE VORTEX JET MILL By electron microscopy to study the microstructure of the cement stone made from Portland cement and activated binders of the compositions in the vortex jet mill. It was found that the open pores of the cement and cementitious compositions prepared using perlite fillers, always filled with tumors, at different stages of collective growth. The microstructure of cementitious compositions has a dense structure by rationally selected composition, effective use of mineral filler - perlite waste, creating additional support for the formation of the internal microstructure of the composite, mechanical activation raw mixture, allowing to obtain composites with desired properties.

scholarly journals The Influence of Thermo-Mechanical Activation of Bentonite on the Mechanical and Durability Performance of Concrete

2019 ◽  
Vol 9 (24) ◽  
pp. 5549 ◽  
Author(s):  
Safi Ur Rehman ◽  
Muhammad Yaqub ◽  
Muhammad Noman ◽  
Babar Ali ◽  
Muhammad Nasir Ayaz Khan ◽  
...  
Keyword(s):  
Portland Cement ◽  
Mechanical Activation ◽  
Mechanical Performance ◽  
Experimental Testing ◽  
Construction Material ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Low Carbon ◽  
Acid Attack ◽  
Split Tensile Strength

Despite presenting a very high global warming toll, Portland cement concrete is the most widely used construction material in the world. The eco-efficiency, economy, and the overall mechanical and durability performances of concrete can be improved by incorporating supplementary cementitious materials (SCMs) as partial substitutions to ordinary Portland cement (OPC). Naturally found bentonite possesses pozzolanic properties and has very low carbon footprint compared to OPC. By applying activation techniques, the reactivity of bentonite can be improved, and its incorporation levels can be maximized. In this study, the influence of mechanical and thermo-mechanical activation of bentonite is investigated on properties of concrete. Bentonite was used for 0%, 10%, 15%, 20%, 25%, 30%, and 35% mass replacements of OPC. Mechanical (compressive strength and split tensile strength) and durability (water absorption, sorptivity coefficient, and acid attack resistance) properties were studied. Results of experimental testing revealed that, concrete containing bentonite showed good mechanical performance, while durability was significantly improved relative to control mix. Application of thermo-mechanical activation can enhance the incorporation levels of bentonite in concrete. At 15% and 25%, bentonite produced optimum results for mechanical and thermo-mechanical activation, respectively. Bentonite inclusion is more beneficial to the durability than the mechanical strength of concrete.

Effect of Ageing Period on Properties of Mechanically Activated Portland Cement

2018 ◽  
Vol 760 ◽  
pp. 37-42
Author(s):  
Karel Dvořák ◽  
Matěj Švéda
Keyword(s):  
Mechanical Properties ◽  
Portland Cement ◽  
Mechanical Activation ◽  
Aging Time ◽  
Ball Mill ◽  
High Speed ◽  
Aging Period ◽  
High Speed Grinding ◽  
Ageing Period ◽  
The Moment

This experiment describes the effects of the aging time since the moment of milling to Portland cements physico-mechanical properties. Possible mechanical activation effects to Portland cement particles has been found. For this experiment two kind of milling technology were used, the conventional milling in a ball mill and high-speed grinding technology in high speed disintegrator and influence of these technologies was also described. The aging period of the cement influences in particular physico-mechanical properties in the early stages of hydration but the final properties after 28 days were not influenced.

Kinetics of Mechanical Activation during the Manufacturing Process of Nanostructured Binders

2014 ◽  
Vol 670-671 ◽  
pp. 412-416 ◽  
Author(s):  
Mariana Nikolaevna Kapusta ◽  
Vadim Kobzev ◽  
Viktoria Nelubova
Keyword(s):  
Portland Cement ◽  
Mechanical Activation ◽  
Manufacturing Process ◽  
Building Materials ◽  
Grinding Process ◽  
Temporal Parameters ◽  
Binding System ◽  
Kinetics Of

Presented article is of interest to specialists in the field of building materials. The provided information describes nanostructured binders (NB) that are promising in the production of building materials for various purposes. As a result of conducted researches the character of hardening kinetics of NB with different composition was identified, which is similar to the classic representative of binding system – Portland cement. The importance of keeping the technological and temporal parameters of NB receipt by comparing it with a quartz suspension was substantiated. Also a system for monitoring the grinding process allowing to control and manage the technology was provided.

scholarly journals Study of integral and differential strength and deformation characteristics of centrifuged and vibrating centrifuged concrete on activated Portland cement

2021 ◽  
Vol 2124 (1) ◽  
pp. 012005
Author(s):  
L R Mailyan ◽  
S A Stel’makh ◽  
E M Shcherban’ ◽  
D S Chernykh
Keyword(s):  
Portland Cement ◽  
Mechanical Activation ◽  
Deformation Characteristics ◽  
Technological Parameters ◽  
Annular Section ◽  
Experimental Laboratory ◽  
Strength And Deformation ◽  
Laboratory Centrifuge

Abstract In this work, the study of integral and differential strength and deformation characteristics of centrifuged and vibrating centrifuged concrete on activated Portland cement was carried out. Mechanical activation of cement was carried out using a specialized grinding unit. Manufacturing of centrifuged and vibrating centrifuged samples was carried out on an experimental laboratory centrifuge. All samples were made of concrete of the same composition. The optimum values of technological parameters of centrifugation and vibrating centrifugation are given. The scheme of obtaining small-size specimens from a common annular section to determine the strength and strain characteristics was developed. According to the results of the study it was found that the improvement of integral and differential strength and strain characteristics when using activated Portland cement is observed for both centrifuged and vibrating centrifuged specimens. However, the samples made by vibrating centrifugation technology have better strength and strain characteristics than the samples made by centrifugation. According to the results of the study, it was found that the activation of Portland cement at its rational values is the best way to enhance variatropy.

scholarly journals The influence of mechanical activation on the process of reaction sintering of Portland cement clinker

2002 ◽  
Vol 34 (1) ◽  
pp. 95-100 ◽  
Author(s):  
Branka Zivanovic ◽  
Tatjana Sreckovic ◽  
M. Komljenovic
Keyword(s):  
Portland Cement ◽  
Mechanical Activation ◽  
Chemical Reactions ◽  
Energy Savings ◽  
Raw Material ◽  
Cement Clinker ◽  
Reaction Sintering ◽  
General Activity ◽  
Portland Cement Clinker

In this paper, results of an investigation of the influence of mechanical activation of a raw material mixture on processes of synthesis and reaction sintering of Portland cement clinker are given. Activation was performed in a vibro mill with rings for 30 minutes in a continual regime in air. It has been established that mechanical activation of the starting raw material mixture increases general activity, which is mostly reflected in reduction of temperatures at which relevant chemical reactions and sintering occur. This is very significant from the viewpoint of the increasingly necessary efficiency and cheaper production, i.e. energy savings during synthesis of Portland cement clinker and indicates that further investigation of the influence of mechanical activation is more than justified.

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