The Effect on Cement Mortar and Concrete by Admixture of Spray Drying Absorption Products

1989 ◽  
Vol 178 ◽  
Author(s):  
Kirsten G. Jeppesen
Keyword(s):  
Grain Size ◽  
Fly Ash ◽  
Cement Mortar ◽  
Setting Time ◽  
Mineralogical Composition ◽  
Cement Clinker ◽  
Strength Development ◽  
Fall Meeting ◽  
Freeze Thaw ◽  
Spray Dried

AbstractSpray dried absorption products (SDA) having special characteristics are used as substitutes for cement in the preparation of mortars; the qualities of the resulting mixed mortars are described. Conditions are described for mortar mixes, data for which were presented at the MRS Fall Meeting 1987.The influence of the composition of the SDA on water requirement and setting time has been studied. A full scale project involving 3 precast, reinforced concrete front-elements containing 20 and 30 wt.% SDA is described. Strength development, mineralogical composition and corrosion were monitored for two years.A non-standard freeze-thaw experiment was performed which compares mortars containing SDA and fly ash (FA) and also shows the effect of superplasticizer.The possibility of improving the SDA by grinding has been tested and a limited improvement has been found. The strength of the mixed mortars seems slightly influenced by the grain size of SDAGypsum (CaSO4·2H2O), synthetic calcium-sulphite (CaSO3·½H2O) and 2 SDAs have been used as retarders for cement clinker. Mortar test prisms have been cast and comparative strengths after curing for 3 years are reported

scholarly journals Influence of Mechanical and Mineralogical Activation of Biomass Fly Ash on the Compressive Strength Development of Cement Mortars

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6654
Author(s):  
Jakub Popławski ◽  
Małgorzata Lelusz
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cement Mortar ◽  
Setting Time ◽  
Green Energy ◽  
Biomass Combustion ◽  
Strength Development ◽  
Compressive Strength Development ◽  
Biomass Fly Ash

Biomass combustion is a significant new source of green energy in the European Union. The adequate utilization of byproducts created during that process is a growing challenge for the energy industry. Biomass fly ash could be used in cement composite production after appropriate activation of that material. This study had been conducted to assess the usefulness of mechanical and physical activation methods (grinding and sieving), as well as activation through the addition of active silica in the form of silica fume, as potential methods with which to activate biomass fly ash. Setting time, compressive strength, water absorption and bulk density tests were performed on fresh and hardened mortar. While all activation methods influenced the compressive strength development of cement mortar with fly ash, sieving of the biomass fly ash enhanced the early compressive strength of cement mortar. The use of active silica in the form of silica fume ensured higher compressive strength results than those of control specimens throughout the entire measurement period.

scholarly journals Influences of Waste Concrete Powder on the Strength Development and Hydration Products of Mortar Containing Fly Ash

2021 ◽  
Author(s):  
Huashan YANG ◽  
Yujun CHE
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Cement Mortar ◽  
Setting Time ◽  
Flow Index ◽  
Strength Development ◽  
Test Results ◽  
Hydration Products ◽  
Waste Concrete ◽  
Time Flow

During recycling waste concrete, a large amount of waste concrete powder (WCP) is generated. However, efficient utilization of WCP remains an unresolved issue. This paper investigates the influences of WCP on the properties and hydration products of cement mortar containing fly ash (FA). This study used two different types of WCPs. One was made from an ordinary Portland cement mortar, and the other was derived from a Portland cement mortar. WCP replaced 10%, 20%, and 30% of FA. The water requirement, setting time, flow index, strength, hydration products, and microstructure of FA mortar incorporating WCP were investigated. Test results indicate that the WCP has no significant influence on the performances and hydration products of FA mortar. By adequately combining WCP and FA, the FA mortar with required performances could be reached.

scholarly journals The Effect of Calcium Formate, Sodium Sulfate, and Cement Clinker on Engineering Properties of Fly Ash-Based Cemented Tailings Backfill

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Wenbin Xu ◽  
Qianlong Li ◽  
Sada Haruna
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Sodium Sulfate ◽  
Setting Time ◽  
Practical Interest ◽  
Engineering Properties ◽  
Cement Clinker ◽  
Strength Development ◽  
Water Rate ◽  
Calcium Formate

The influence of admixtures on the engineering properties of fly ash-based cemented tailings backfill (CTB) is a topic of significant practical interest, as it affects the backfilling cost and the environmental effect of mining operation. This paper presents results of an experimental study on the influence of different activators on the engineering properties of the CTB containing fly ash. CTB samples are mixed with different contents of calcium formate, sodium sulfate, and cement clinker (4%, 8%, and 12% by mass of total binder) and cured in a cubic chamber (at 20°C and RH 90 ± 5%) for 3, 7, and 28 days. Specimen tests were performed to assess the slump height, setting time, leaching water rate, vertical settlement, and strength development. Furthermore, the XRD analyses were conducted on the hydration products of fly ash-based CTB mixtures. The results show that activators can cause decrease in the slump height, leaching water rate, and vertical settlement of fly ash-based CTB mixtures. However, inclusion of cement clinker ranging from 8%–12% of total binder can reduce the slump height, setting time, leaching water rate, and vertical settlement to an acceptable range. Addition of calcium formate in the fly ash-based CTB caused negligible change in compressive strength. The compressive strength improved with higher content of sodium sulfate and cement clinker at the age of 28 days. XRD analyses showed considerable intensity counts of C-S-H gel, calcium hydroxide, and ettringite, resulting from the addition of sodium sulfate and cement clinker. This study also shows that an understanding of the effect of activators on the engineering properties of fly ash-based CTB is crucial for designing a cost-effective and workable CTB with reduced environmental impact.

scholarly journals Effect of calcium-rich compounds on setting time and strength development of alkali-activated fly ash cured at ambient temperature

2018 ◽  
Vol 9 ◽  
pp. e00198 ◽  
Author(s):  
Prinya Chindaprasirt ◽  
Tanakorn Phoo-ngernkham ◽  
Sakonwan Hanjitsuwan ◽  
Suksun Horpibulsuk ◽  
Anurat Poowancum ◽  
...  
Keyword(s):  
Fly Ash ◽  
Ambient Temperature ◽  
Setting Time ◽  
Strength Development ◽  
Alkali Activated

Preparation and Mechanical Performance of Sulpoaluminate Cement by Using Industrial Solid Wastes

2017 ◽  
Vol 726 ◽  
pp. 510-514
Author(s):  
Shi Zhen Zhao ◽  
Feng Lan Han ◽  
Gui Qun Liu ◽  
Mao Hui Li ◽  
Yu Jie Chen
Keyword(s):  
Fly Ash ◽  
Mechanical Performance ◽  
Cement Mortar ◽  
Raw Materials ◽  
Industrial Process ◽  
Chemical Characteristic ◽  
Cement Clinker ◽  
Hydration Mechanism ◽  
Water To Cement Ratio ◽  
Physical And Chemical

By using Mn slag, Mg slag and Fly ash which comes from industrial process in Ningxia province as raw materials, the sulpoaluminate cement was prepared via sintering raw materials in a furnace. The physical and chemical characteristic of sulpoaluminate cement clinker was tested. The optimal proportion of clinkers is also determined by the results of phase composition, microstructure and hydration mechanism. The results shows that when the mixed ratio of Mn slag, Mg slag and Fly ash is 21%, 21% and 0% respectively in the raw materials and the calcination temperature is 1300 °C for 30 min, sulphoaluminate cement clinker with maximum amount of C4A3S, C2S and C4AF was prepared. Then, natural gypsum was added into the clinker powder with a ratio of 15% to make cement materials. When water to cement ratio is 0.5 and cement to sand ratio is 1:3, the cement mortar obtain a compressive strength of 22.22 MPa at 3d, 31.2 MPa at 7 d, and the flexural strength of 3.86MPa at 3d, and 4.83 MPa at 7d respectively.

scholarly journals Alkali-Activated Hybrid Concrete Based on Fly Ash and Its Application in the Production of High-Class Structural Blocks

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 946
Author(s):  
Oriana Rojas-Duque ◽  
Lina Marcela Espinosa ◽  
Rafael A. Robayo-Salazar ◽  
Ruby Mejía de Gutiérrez
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Modulus ◽  
Setting Time ◽  
Modulus Of Rupture ◽  
Strength Development ◽  
Block Type ◽  
High Class ◽  
Structural Blocks ◽  
Alkali Activated

This article reports the production and characterization of a hybrid concrete based on the alkaline activation of a fly ash (FA) of Colombian origin, which was added with 10% Portland cement (OPC) in order to promote the compressive strength development at room temperature. The alkali-activated hybrid cement FA/OPC 90/10 was classified as a low heat reaction cement (type LH), according to American Society of Testing Materials, ASTM C1157; the compressive strength was of 31.56 MPa and of 22.68 MPa (28 days) at the levels of paste and standard mortar, respectively, with an initial setting time of 93.3 min. From this binder, a hybrid concrete was produced and classified as a structural type, with a compressive strength of 23.16 MPa and a flexural modulus of rupture of 5.32 MPa, at 28 days of curing. The global warming potential index (GWP 100), based on life cycle analysis, was 35% lower than the reference concrete based on 100% OPC. Finally, its use was validated in the manufacture of a solid block-type construction element, which reached a compressive strength of 21.9 MPa at 28 days, exceeding by 40.6% the minimum strength value established by the Colombia Technical Standard, NTC 4026 (13 MPa) to be classified as high class structural blocks.

scholarly journals Durability of concrete containing ternary blends of high calcium fly ash and slag

2021 ◽  
Author(s):  
Seyon Kandasamy
Keyword(s):  
Fly Ash ◽  
Setting Time ◽  
Sulfate Attack ◽  
Alkali Silica Reaction ◽  
Ternary Blends ◽  
Fresh Properties ◽  
Freeze Thaw ◽  
Salt Scaling ◽  
High Calcium ◽  
High Calcium Fly Ash

This thesis investigates the performance of ternary blends containing high calcium fly ash (HCFA) and slag against: sulfate attack, alkali-silica reaction (ASR), salt scaling, and freeze-thaw damage. In addition, compressive strength, permeability and fresh properties were evaluated. In terms of sulfate attack, the performance of HCFA was significantly enhanced when slag was added to the mix, and the same was found for ASR. The high efficacy in resisting ASR of HCFA/slag blends was found to be a result of the blends' ability to bind and retain alkalis. Regarding the salt scaling, the tested ternary concretes failed the Ministry of Transportation Ontario limit, 0.8 kg/m²; however, enhanced performance was achieved when the samples were cured by wrapping with plastic sheets. Ternary blends achieved high resistance to freezing/thawing and less bleeding compared to those of the control mix without slag or HCFA; however, setting time was dragged by about an hour.

Interrelationship Analysis of Geopolymer Components Using Pearson Correlation Technique

2014 ◽  
Vol 567 ◽  
pp. 417-421 ◽  
Author(s):  
Andri Kusbiantoro ◽  
Norbaizurah Rahman ◽  
Noor Fifinatasha Shahedan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Elemental Composition ◽  
Setting Time ◽  
Source Material ◽  
Curing Temperature ◽  
Strength Development ◽  
Correlation Technique ◽  
High Calcium ◽  
Geopolymer Binder

Performance of geopolymer based specimens is significantly affected by internal and external aspects. Curing temperature and air humidity are among the prominent external factors that contribute to the alteration of geopolymer properties. Nevertheless, internal component of geopolymer binder also carries essential effect to the hardened geopolymer binder produced. In this research, the study was concentrated on the elemental composition of source material components and their interrelation to the performance of geopolymer binder produced. Different types of fly ash were used as the source material in this research. Low calcium (class-F) fly ash was combined with high calcium (class-C) fly ash to determine the elemental composition effect, particularly SiO2, Al2O3, and CaO to the geopolymer properties. Analysis using SYSTAT statistical software indicated the importance of oxide composition of source material to the geopolymer specimens produced. Initial setting time of geopolymer paste was also possibly important to the compressive strength of geopolymer specimens produced. Nevertheless, final setting time indicated less importance to the compressive strength development of geopolymer binder.

Properties of Phosphate Cement Mortar Used as Rapid-Repair Material

2011 ◽  
Vol 250-253 ◽  
pp. 1752-1756 ◽  
Author(s):  
Hong Wei Deng ◽  
Ying Zi Yang ◽  
Xiao Jian Gao
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
No Reduction ◽  
Cement Mortar ◽  
Magnesium Phosphate ◽  
Strength Development ◽  
Repair Material ◽  
Rapid Repair ◽  
Repair Materials ◽  
Early Strength

In order to determine the optimal proportion of magnesium phosphate cement mortar, the influences of ratio of magnesium phosphate cement-based binder (MPB) to sand (MPB/S), effects of fly ash on fluidity and strength development of MPB mortar, and the compatibility between MPB and traditional concrete and shrinkage of MPB mortar were investigated in this paper. The optimal proportion in this test was: setting adjusting agent of 12%, P/M ratio of 1:2(in weight), MPB/S ratio of 1:1 and FA/S ratio of 15%. The results showed that the MPB mortar met the higher early strength requirement of rapid-repair materials, with compressive strength beyond 50MPa and flexural strength more than 9.1MPa at 3 hours, and at later ages no reduction of strength happened. There was a good compatibility between MPB and traditional concrete. The shrinkage of MPB mortar at 28 days was less than 2.89 × 10-4. Therefore MPB is very suitable for rapid repairing of concrete structures.

scholarly journals Features of use of unlawful kaolin for the manufacture of a cement clinker

2018 ◽  
pp. 6-13
Author(s):  
M.Yu. Tsybenko ◽  
L.P. Chernyak ◽  
V.G. Salnik ◽  
N.O. Dorogan
Keyword(s):  
Fly Ash ◽  
Phase Transformations ◽  
Raw Materials ◽  
Mineralogical Composition ◽  
Raw Material ◽  
Cement Clinker ◽  
The Subject ◽  
Clay Component ◽  
The Given ◽  
Scientific Ideas

Results over of research of the silicate systems of carbonate raw material with the varieties of clay component for making of cement clinker. The features of the chemical-mineralogical composition, phase transformations during burning and astringent properties of clinker are shown when unenriched kaolin and fly ash are used as alumina-silica-containing components of the initial raw material mixture. In the chemical technology of hydraulic mineral astringents, clay raw material serves, first of all, as a source of SiO , Al O , Fe O oxides, which must form from CaO during the baking of crystalline phases of silicates, aluminates and calcium aluminferrite, with the development of which impart the properties of the product of production. In turn, the above oxides arise in the process of technology during the heat treatment of raw mixtures due to the destruction of the lattice of rock-forming minerals. Hence the obvious dependence of the number and reactivity of oxides on the chemical and mineralogical composition of clay raw material, which, according to essential differences, is classified into a number of groups. Deepening of scientific ideas about this dependence can become an additional factor for im- proving the intensification of the technology of silicate binders, which became the subject of research in the given work. The chemical and mineralogical composition of the clay component of raw materials for the production of clinker and cement based on it is an important factor in the structure of the binder material at the stages of the technological process and the determination of the properties of the final product. Taking into account the peculiarities of the composition of unbleached kaolin (high content of kaolinite, quartz, feldspar), the feasibility of its application in the production of cement for clinker production is related to the possibility of adjusting the kinetics and the direction of phase transformations during the burning of the material. From the point of view of resource conservation and technology, the complex application of aluminum and silicon-containing raw materials components of natural (unaffected kaolin) and man-made (fly ash) origin is shown. Deepening of scientific ideas about this dependence can become an additional factor for improving the intensification of the technology of silicate binders, which became the subject of research in the given work.

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