scholarly journals Estimation of Hydration Degree of Blended Cements with the Help of k-Values

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2420 ◽  
Author(s):  
Reiterman ◽  
Holčapek ◽  
Davidová ◽  
Jaskulski ◽  
Keppert
Keyword(s):  
Portland Cement ◽  
Ceramic Powder ◽  
Numerical Estimation ◽  
Time Intervals ◽  
Blended Cements ◽  
Degree Of Hydration ◽  
Mineral Additives ◽  
Furnace Slag ◽  
Active Mineral Additives

The growing utilization of various mineral additives in the building industry has caused concern worldwide to reduce the emissions of carbon dioxide from Portland cement (OPC) production. The present paper is focused on the determination of the degree of hydration of blended binding systems based on Portland cement. Blast furnace slag, fly ash, and ceramic powder are used in the study; they are applied by 12.5 wt.% up to 50% of OPC replacement. The evolution of the hydration process is monitored using thermogravimetry in selected time intervals to determine the degree of hydration; its ultimate value is obtained from numerical estimation using the Michaelis-Menten equation. However, due to the application of active mineral additives, the correction in terms of equivalent binder is conducted. Corrected values of the degree of hydration exhibit good fit with compressive strength.

Calorimetric determination of the effect of additives on cement hydration process

2013 ◽  
Vol 67 (2) ◽  
Author(s):  
Pavel Šiler ◽  
Josef Krátký ◽  
Iva Kolářová ◽  
Jaromír Havlica ◽  
Jiří Brandštetr
Keyword(s):  
Portland Cement ◽  
Silica Fume ◽  
Maximum Temperature ◽  
Granulated Blast Furnace Slag ◽  
Mineral Components ◽  
Maximum Temperatures ◽  
The Impact ◽  
Furnace Slag ◽  
Calorimetric Determination

AbstractPossibilities of a multicell isoperibolic-semiadiabatic calorimeter application for the measurement of hydration heat and maximum temperature reached in mixtures of various compositions during their setting and early stages of hardening are presented. Measurements were aimed to determine the impact of selected components’ content on the course of ordinary Portland cement (OPC) hydration. The following components were selected for the determination of the hydration behaviour in mixtures: very finely ground granulated blast furnace slag (GBFS), silica fume (microsilica, SF), finely ground quartz sand (FGQ), and calcined bauxite (CB). A commercial polycarboxylate type superplasticizer was also added to the selected mixtures. All maximum temperatures measured for selected mineral components were lower than that reached for cement. The maximum temperature increased with the decreasing amount of components in the mixture for all components except for silica fume. For all components, except for CB, the values of total released heat were higher than those for pure Portland cement samples.

scholarly journals Fine ground granulated blast furnace slag for saving quantity of binder

2019 ◽  
Vol 110 ◽  
pp. 01055
Author(s):  
Liliya Kazanskaya ◽  
Nicolay Privalov ◽  
Svetlana Privalova
Keyword(s):  
Blast Furnace ◽  
Portland Cement ◽  
Blast Furnace Slag ◽  
Mineralogical Composition ◽  
High Specific Surface Area ◽  
Resource Saving ◽  
Water Reduction ◽  
Granulated Blast Furnace Slag ◽  
Mineral Additives ◽  
Furnace Slag

Nowadays, it is acknowledged that the use of mineral additives based on ground slag is one of ways of resource saving and improvement of technical properties of cement composites. Mineral additives with fineness similar to the Portland cement fineness are often used to replace part of Portland cement. Two kinds of ultra-fine ground granulated blast furnace slag that differ in composition and fineness were studied in the paper. Water-reduction due to effect of super plasticizer in slag-Portland cement compositions with amount of slag up to 70% was studied. The results of reduction of binder quantity per 1 kg of chemical admixture due to significant water-reduction are obtained and analysed. Correlations depending on kind, amount and fineness of slags, as well as depending on mineralogical composition of Portland cement were stated. The ultra-fine mineral additives based on ground slag with high specific surface area can be used for significant reduction of compositional binder.

scholarly journals Use of Slag from the Combustion of Solid Municipal Waste as A Partial Replacement of Cement in Mortar and Concrete

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1593
Author(s):  
Monika Czop ◽  
Beata Łaźniewska-Piekarczyk
Keyword(s):  
Blast Furnace ◽  
Portland Cement ◽  
Municipal Solid Waste ◽  
Silica Fume ◽  
Blast Furnace Slag ◽  
Waste Incineration ◽  
Municipal Solid Waste Incineration ◽  
Granulated Blast Furnace Slag ◽  
Mineral Additives ◽  
Furnace Slag

In Europe, the use of wastes in the cement and construction industry follows the assumptions of sustainability and the idea of circular economy. At present, it is observed that cement plants introduce wastes to the cement in the form of so-called mineral additives. The most often used mineral additives are: fly ash with silica fume, granulated blast furnace slag and silica fume. The use of mineral additives in the cement is related to the fact that the use of the most expensive component of cement—Portland cement clinker—is limited. The purpose of the article is a preliminary evaluation of the suitability of slag from the municipal solid waste incineration plant for its use as a replacement of cement. In this article, slag from the municipal solid waste incineration (MSWI) replaces cement in the quantity of 30%, and presents the content of oxides and elements of slag from the MSWI. The obtained results are compared to the requirements that the crushed and granulated blast furnace slag need to meet to be suitable for use as an additive of type II to the concrete. The conducted analyses confirmed that the tested slag meets the requirements for the granulated blast furnace slag as an additive to the concrete in the following parameters: CaO ≤ 18.0%, SO3 ≤ 2.5% and Cl ≤ 0.1%. At the same time, mechanical features were tested of the designed mortars which consisted of a mixture of Portland cement (CEM I) with 30% of slag admixture. The designed mortar after 28 days of maturing reached a compressive strength of 32.0 MPa, and bending strength of 4.0 MPa. When compared to the milled granulated blast furnace slag (GBFS), the obtained values are slightly lower. Furthermore, the hardened mortars were subject to a leachability test to check the impact on the environment. Test results showed that the aqueous extracts from mixtures with 30% of slag admixtures slightly exceed the limits and do not pose a sufficiant threat to the environment as to eliminate the MSWI slag from economical use.

scholarly journals Definition Of Puzzolanic Properties Active Mineral Additives In Portlandcement

2021 ◽  
Vol 03 (03) ◽  
pp. 7-12
Author(s):  
Gulsanam Ruzimurodovna Tursunova ◽  
◽  
Farrukh Bakhtiyarovich Atabaev ◽  
Keyword(s):  
Portland Cement ◽  
Cement Stone ◽  
Industry Waste ◽  
Natural Production ◽  
Production And Consumption ◽  
Mineral Additive ◽  
Definition Of ◽  
Mineral Additives ◽  
Mineralizing Additive ◽  
Active Mineral Additives

The article presents the results of testing the use of Angren dry remote active ash and slag in Portland cement as an active mineral additive. It was found that Portland cement with the addition of Angren dry remote active ash and slag renders karrazastoy, ekanomet clinker and it is proved that hydro removed ash and slag (2011 year) does not recommend as an active mineral additive. Therefore, dry remote active ash and slag is recommended for use as an active mineral additive in the production of cement, improving its construction and technical properties. The possibility of using Angren dry remote active ash and slag as an active mineral component for producing cements with low corrosion resistance is shown. Angren dry remote active ash and slag contributes to the formation of the structure of the cement stone, increases its density and strength against aggressive ions, causing increased resistance in aggressive environments. And save up to 30% of cement. It has been established that Portland cement with the addition of Angren dry remote active ash and slag has an intensifying effect on the formation of clinker minerals. Therefore, the Angren dry remote active ash and slag is recommended for use as a mineralizing additive in the production of cement. Use of chemical industry waste with replacement of expensive natural production and consumption waste. At the same time, an environmental problem is being addressed.

scholarly journals Freeze-Thaw Resistance of Cement Screed with Various Supplementary Cementitious Materials

2019 ◽  
Vol 58 (1) ◽  
pp. 66-74 ◽  
Author(s):  
Pavel Reiterman ◽  
Ondřej Holčapek ◽  
Ondřej Zobal ◽  
Martin Keppert
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Frost Resistance ◽  
Blast Furnace Slag ◽  
Ceramic Powder ◽  
Supplementary Cementitious Materials ◽  
Partial Replacement ◽  
Freeze Thaw ◽  
Mineral Additives ◽  
Furnace Slag

Abstract This paper describes a study of the effect of partial replacement of ordinary Portland cement (OPC) by various mineral additives in the screed mixtures. Ceramic powder, blast furnace slag and fly ash were gradually employed in increments of 12.5 wt.% up to 50 wt.% to replace OPC. The mixtures were designed to a constant consistency. The influence of mineral additives was evaluated in terms of the air content in the fresh mixtures, the compressive strength, the flexural strength and the freeze-thaw resistance and using non-destructive measurements after 28 and 90 days. The accompanied paste sampleswere analysed using thermogravimetry to monitor the hydration process by means of total bound water content. The decrease in the mechanical properties and the frost resistance of the mixtures with the mineral additives were recorded, because of the necessity for a larger addition of water. According to the valid standards for concrete screed related to the frost resistance, it could be concluded that maximal suitable cement replacement contents are 12.5, 37.5 and 50 wt.% for ceramic powder, fly ash and blast furnace slag, respectively. The freeze-thaw resistance of the studied materials was found to be strongly related to the content of CSH and CAH hydrates.

scholarly journals Surface Characteristics of Portland Cement/Blast Furnace Slag Mixtures

1996 ◽  
Vol 13 (6) ◽  
pp. 461-467 ◽  
Author(s):  
Kh.A. Khalil
Keyword(s):  
Blast Furnace ◽  
Portland Cement ◽  
Blast Furnace Slag ◽  
Surface Characteristics ◽  
Hydration Products ◽  
Cement Pastes ◽  
Degree Of Hydration ◽  
Granulated Blast Furnace Slag ◽  
Granulated Slag ◽  
Furnace Slag

The effect of the degree of hydration and amounts of granulated blast furnace slag on the surface properties of Portland cement pastes were studied. The results obtained showed that the specific surface area SBET (m2/g) and pore volume Vp (cm3/g) decreased on increasing the degree of hydration. The addition of different amounts of granulated slag effected a decrease in SBET and Vp to an extent proportional to the amount present. These results were attributed to a replacement of clinker by the amounts of slag added and the formation of hydration products.

scholarly journals The clays after heat treatment as the concrete active mineral additive

2018 ◽  
Vol 170 ◽  
pp. 03021
Author(s):  
Olga Bazhenova ◽  
Sofia Bazhenova ◽  
V. Nemirova ◽  
Dmitriy Bazhenov
Keyword(s):  
Heat Treatment ◽  
Portland Cement ◽  
Raw Material ◽  
Cement Stone ◽  
Material Resources ◽  
Mineral Additive ◽  
Granulated Slag ◽  
Technical Properties ◽  
Mineral Additives ◽  
Active Mineral Additives

Active mineral additives are one of the most common components of cement systems now. They are entered cements of increase in extent of hydration, the directed formation of structure of a cement stone from more stable hydrate phases of the lowered basicity, for the purpose of improvement of construction and technical properties of cements, by cutting of costs of fuel raw material resources for their production, giving to cements of some specific properties. In work the possibility of use as active mineral additives not only the granulated slags, but also local clays which industrially can give certain puzzolan properties are considered. It is proved that heat treatment of clay breeds significantly increases their puzzolan activity that does them suitable for use as active mineral additive instead of the domain granulated slag by production of the portland cement.

scholarly journals MODERN TECHNOLOGIES OF MATERIALS FOR PROTECTION THE WORKING SURFACES OF HYDROCLONE AGAINST WEAR

2019 ◽  
Vol 4 (7) ◽  
pp. 135-139
Author(s):  
Ю.М. Фадин ◽  
Yuriy Fadin ◽  
П. Хахалев ◽  
Pavel Hahalev ◽  
Е. Трапезникова ◽  
...  
Keyword(s):  
Portland Cement ◽  
Cement Clinker ◽  
Cement Production ◽  
Wet Process ◽  
Working Surface ◽  
Hydraulic Binder ◽  
Calcium Silicates ◽  
Mineral Additives ◽  
Modern Technologies ◽  
Active Mineral Additives

The article considers the process of portland cement production by wet process. Portland cement is a hydraulic binder that is produced by cement clinker, gypsum and additives. Calcium silicates are commonly used as additives. Portland cement production consists of following processes: crushing of clinker and gypsum stone; preparation of mineral additives (crushing, drying); grinding of clinker with active mineral additives and gypsum; storage, packaging and shipping the cement to consumer. Since grinding is carried out in a closed cycle, it is necessary to select the classifying equipment. For this purpose, an analysis is made, which reveals that the hydrocyclone is the most multi-purpose and less expensive in operation of classifying equipment. The study of the hydrocyclone design demonstrates a significant drawback in the form of increased wear of the hydrocyclone working surfaces, which has an impact on durability and work efficiency. The degree of wear the hydrocyclone surfaces depends on the nature of the pulp impact and the mechanical characteristics of material of the hydrocyclone working surface. This article is devoted to the study of the most popular and frequently used wear-resistant materials to protect work surfaces from wear.

scholarly journals Mechanisms Accompanying Chromium Release from Concrete

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1891 ◽  
Author(s):  
Anna Król
Keyword(s):  
Portland Cement ◽  
Building Materials ◽  
Portland Cement Concrete ◽  
Chromium Release ◽  
Granulated Blast Furnace Slag ◽  
Diffusion Controlled ◽  
Tank Test ◽  
Mineral Additives ◽  
Furnace Slag

The use of mineral additives from the power and metallurgy industries in the production of building materials still raises questions about the ecological safety of such materials. These questions are particularly associated with the release of heavy metals. The article presents research related to the leaching of chromium from concretes made of Portland cement CEM I and slag cement CEM III/B (containing 75% of granulated blast furnace slag). Concrete was evaluated for leaching mechanisms that may appear during tank test over the long term (64 days). It has been presented that the dominating process associated with the leaching of chromium from both types of concrete is surface wash-off. Between the 9th and 64th day of the test, leaching of Portland cement concrete can be diffusion controlled. It has been proven that the participation of slag in the composition of concrete does not affect the level of leaching of chromium into the environment from concrete.

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