Mechanical Properties of Mortars Based on Roman Cement with the Addition of Power Plant Fly Ash

2020 ◽  
Vol 868 ◽  
pp. 39-44
Author(s):  
Jana Daňková ◽  
Tereza Majstríková ◽  
David Bujdoš ◽  
Pavel Mec
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Raw Materials ◽  
Strength Increase ◽  
Low Carbon ◽  
Slow Increase ◽  
Initial Strength ◽  
Hydraulic Binder ◽  
Long Lifetime ◽  
Reference Mixture

Roman cement is a historic hydraulic binder, prepared by firing of limestone with high proportion of clay minerals, usually at temperatures below the sintering point. The firing temperatures of Roman cements range from 800 to 1200°C. At present, this binder is considered to be a promising material with a low carbon footprint and a long lifetime. The properties of Roman cement are influenced by many factors, especially raw materials composition and firing conditions. On the other hand, a disadvantage of mortars based on Roman cement is a slow increase of initial strength. In this paper, the influence of power fly ash admixture on the dynamics of initial strength increase was experimentally investigated. The characteristics of mortars with admixtures were compared with the properties of reference mortar without admixtures. The Roman cement Vicat Prompt TM Natural Cement (manufactured by Vicat SA, French company) was used as a binder. Based on the results of the experiment it can be stated that mortars with the admixture of power plant fly ash show higher dynamics of the increase of initial strengths than the reference mixture.

scholarly journals Influence of Fly Ash Additive on the Properties of Concrete with Slag Cement

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3265 ◽  
Author(s):  
Anna Szcześniak ◽  
Jacek Zychowicz ◽  
Adam Stolarski
Keyword(s):  
Fly Ash ◽  
Chloride Ion ◽  
High Strength ◽  
Experimental Tests ◽  
Chloride Ions ◽  
Strength Increase ◽  
Slag Cement ◽  
Initial Strength ◽  
Chloride Ion Penetration ◽  
The Impact

This paper presents research on the impact of fly ash addition on selected physical and mechanical parameters of concrete made with slag cement. Experimental tests were carried out to measure the migration of chloride ions in concrete, the tightness of concrete exposed to water under pressure, and the compressive strength and tensile strength of concrete during splitting. Six series of concrete mixes made with CEM IIIA 42.5 and 32.5 cement were tested. The base concrete mix was modified by adding fly ash as a partial cement substitute in the amounts of 25% and 33%. A comparative analysis of the obtained results indicates a significant improvement in tightness, especially in concrete based on CEM IIIA 32.5 cement and resistance to chloride ion penetration for the concretes containing fly ash additive. In the concretes containing fly ash additive, a slower rate of initial strength increase and high strength over a long period of maturation are shown. In accordance with the presented research results, it is suggested that changes to the European standardization system be considered, to allow the use of fly ash additive in concrete made with CEM IIIA 42.5 or 32.5 cement classes. Such a solution is not currently acceptable in standards in some European Countries.

Fundamentals of Geopolymers and Related Alkali Activated Materials

2014 ◽  
Vol 803 ◽  
pp. 144-147 ◽  
Author(s):  
J. Temuujin ◽  
A. Minjigmaa ◽  
U. Bayarzul ◽  
Ts. Zolzaya ◽  
B. Davaabal ◽  
...  
Keyword(s):  
Fly Ash ◽  
Building Materials ◽  
Raw Materials ◽  
Construction Materials ◽  
Materials Chemistry ◽  
Low Carbon ◽  
Pond Ash ◽  
Sustainable Usage ◽  
By Products ◽  
Alkali Activated

With the increasing rate of depletion of natural raw materials for production of building materials, their sustainable usage is clearly an important topic for consideration. For instance, 1 tonne ordinary Portland cement (OPC) requires 1.7 tonnes of raw materials, 1.0 tonne of coal and 100 kWh of electricity. One tonne of cement emits 0.8 - 1 tonne of CO2 into atmosphere globally contributing ~5% of total manmade carbon dioxide. Therefore, the development of new, sustainable, low carbon footprint construction materials is an important task for materials scientists and civil engineers. One type of binder that is attracting particular attention around the world is alkali-aluminosilicate chemistry based material the so-called geopolymers. In this presentation we will discuss the fundamentals of geopolymer chemistry and the similarities to and differences from conventional alkali activated materials chemistry. Particular attention will be given to our latest results on the preparation of geopolymer type paste and concrete from fly ash. Mechanical activation of fly ash caused a decrease in porosity with a partial amorphisation of the crystalline constituents. Geopolymer type paste prepared from 30 minute milled Darkhan pond ash showed increase in 7 day compressive strengths by 7 times reaching of 15.4 (4.6) MPa. Keywords: Geopolymer binder, alkali-activated materials, coal combustion by products

Study of Effect of Chemical Activators and Mineral Admixtures on the Strength of HFGD Gypsum - Fly Ash Cementing Material

2011 ◽  
Vol 71-78 ◽  
pp. 3725-3728
Author(s):  
Xin Tang Wang ◽  
Yi Zhang ◽  
Jie Yin ◽  
Zhi Guo Xie
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Raw Materials ◽  
Experimental Results ◽  
Mineral Admixtures ◽  
Single Factor ◽  
Related Factors ◽  
Fgd Gypsum ◽  
Cementing Material ◽  
Hemi Hydrate

A kind of FGD gypsum from Ningbo Beilun Power Plant of China and fly ash were used as the raw materials with which a complex cementing material was made. Effect of the related factors such as water proportion, mineral admixtures and chemical activators on characteristics of Hemi-hydrate FGD gypsum-fly ash complex cementing material is studied through a number of single factor experiments. The experimental results show that an appropriate amount of admixtures can effectively improve the strength of the Hemi-hydrate FGD gypsum–fly ash complex cementing material presented here. It is concluded that the strength of HFGD-FACM is best as the ratio of HFGD gypsum and fly ash is 1:1 and proper water aggregate proportion is 0.45~0.50.

scholarly journals Beneficiated ponded fly ash for concretes with high volume mineral additions

2020 ◽  
Vol 315 ◽  
pp. 07006
Author(s):  
Nikolai Zaichenko ◽  
Irina Petrik ◽  
Liudmila Zaichenko
Keyword(s):  
Fly Ash ◽  
High Volume ◽  
High Rate ◽  
Unburned Carbon ◽  
Strength Increase ◽  
Low Carbon ◽  
Cement Pastes ◽  
Technical Requirements ◽  
Mineral Additions ◽  
High Level

The article presents the investigation results of effect of beneficiated ponded fly ash on the properties of cement pastes and concretes with high-level replacement of Portland cement. To improve the characteristics of ponded fly ash meeting technical requirements for replacing cement in concrete the triboelectrostatic beneficiation technology has been elaborated. This technology can produce low-carbon ash product (LOI = 2.52 % in this study) for the high replacing level of cement (45 %) in concretes. The beneficiated ponded fly ash has an improved granulometric and phase composition, a decreased content of unburned carbon that accelerates the hydration process of cement, increases the rheological properties of cement paste and the ability of air-entraining admixture to hold the required involved air. In a combination with the nanostructured-carbon-based plasticizing admixture the beneficiated ponded fly ash exhibits high rate of strength increase when is used in high-volume fly ash concretes.

Preparation of Glass Ceramic Made from Fly Ash

2011 ◽  
Vol 295-297 ◽  
pp. 487-490 ◽  
Author(s):  
Feng Li ◽  
Xiang Dong Liu
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Glass Ceramic ◽  
Raw Materials ◽  
Melting Method ◽  
Crystal Nucleus

Using fly ash from the power plant and SiO2 as the main raw materials, glass-ceramic was prepared by melting method. By means of DSC, XRD and SEM, the crystallizations of CaO-Al2O3-SiO2 system glass-ceramic were studied. The results show that it is more and more difficult to crystallize as the content of SiO2 increases. When the content of SiO2 reaches to 41.5%, the crystal nucleus form in the form of shuttle shape, the crystals develop in the same direction for a certain zone. But the crystals develop into hexagon shape finally when they are heated for 1 h at 1100°Cafter nucleation at 780°C.The developed crystals are anorthite. The sizes of crystals are between 1- 1.5μm, their microhardness can reach HV804.

scholarly journals Suitability of modified low carbon Roman cements for architectural restoration

2021 ◽  
Vol 280 ◽  
pp. 07002
Author(s):  
Myroslav Sanytsky ◽  
Tetiana Kropyvnytska ◽  
Roman Kotiv ◽  
Mykola Bevz ◽  
Stanislav Fic
Keyword(s):  
Setting Time ◽  
High Surface ◽  
Weather Conditions ◽  
High Porosity ◽  
Low Carbon ◽  
Initial Strength ◽  
Building Facades ◽  
Hydraulic Binder ◽  
History Of ◽  
Architectural Restoration

Article is devoted to the investigation of suitability of low carbon Roman cement for restoration and finishing works. The history of the development of Roman cement as a natural hydraulic binder, which was commonly used to decorate building facades in the 19th and early 20th centuries, is presented. The properties of mortars based on Roman cement make it an excellent product for architectural restoration and conservation, as they are characterized by fast setting, high porosity typical for lime mortars, high resistance to weather conditions, high initial strength. At the same time, due to the high surface activity and increased water demand for cement, with the age of hardening, shrinkage deformations can develop, which leads to the formation of main cracks on the surface of the products. It is shown that the addition of gypsum is an effective regulator of the setting time of Roman cement and contributes to an increase in the strength of the cement paste. Analogs of Roman cement based on multicomponent cement binders modified with plasticizing and air-entraining additives are presented.

FLY ASH FROM THERMAL POWER PLANT, RAW MATERIAL FOR GLASS-CERAMIC

2013 ◽  
Vol 12 (2) ◽  
pp. 337-342 ◽  
Author(s):  
Firuta Goga ◽  
Roxana Dudric ◽  
Calin Cormos ◽  
Florica Imre ◽  
Liliana Bizo ◽  
...  
Keyword(s):  
Fly Ash ◽  
Power Plant ◽  
Glass Ceramic ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Raw Material ◽  
Plant Raw Material

The Influence of the Ash Addition from Thermal Power Plant on the Mechanical, Thermal and Dielectric Characteristics of Mortars

2018 ◽  
Vol 69 (8) ◽  
pp. 2040-2044
Author(s):  
Georgeta Velciu ◽  
Virgil Marinescu ◽  
Adriana Moanta ◽  
Ladislau Radermacher ◽  
Adriana Mariana Bors
Keyword(s):  
Thermal Conductivity ◽  
Fly Ash ◽  
Power Plant ◽  
Cement Mortar ◽  
Thermal Power ◽  
Total Content ◽  
Ash Content ◽  
Dielectric Losses ◽  
Dielectric Characteristics ◽  
Cement Mortars

The influence of fly ash adittion (90 % fraction [ 100 mm) on the cement mortar characteristics was studied. The XRD, XRF, SEM and FTIR determinations indicated that fly ash used has a hollow microstructure of microsphere and cenosphere whose total content in SiO2, Al2O3 and Fe2O3 is 88.63 % and that of CaO and MgO of 8.55 %. The mechanical, thermal and dielectric determinations made on mortar samples with content of fly ash in the 0-40 % range have highlighted fact that the mechanical strength of cement mortars is maximal at 20 %, the increase in fly ash content leads to a decrease in relative density and thermal conductivity as well as and to increased dielectric losses tgd.

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