scholarly journals Development of Fly Ash Composite Binder and Optimization of Slurry Ratio

2021 ◽  
Author(s):  
Qingfeng Zhuo ◽  
Lei Ba ◽  
Jing Wang ◽  
Qifeng Wang
Keyword(s):  
Fly Ash ◽  
Mass Fraction ◽  
Cementitious Materials ◽  
Physicochemical Analysis ◽  
Ratio Test ◽  
Composite Binder ◽  
Bleeding Rate ◽  
Slag Powder ◽  
Body Strength ◽  
Cemented Backfill

In view of the high cost of cement filling, the new cementitious materials are developed by using solid waste resources. Firstly, on the basis of material physicochemical analysis, the fly ash composite cementation ratio test and optimization test are carried out to determine the optimal ratio. Then, the filling body strength and pipeline transportation characteristics test are carried out to analyze they influence law. Finally, the genetic algorithm is used to optimize the slurry ratio. The results show that the strength of cemented backfill increases linearly with the increase of slurry concentration; The slump and bleeding rate of slurry decrease with the increase of slurry mass fraction, and increase with the decrease of binder sand ratio, the optimal proportion of fly ash (FA) based composite binder is w(FA): w(clinker): w (desulfurized gypsum (DG)): w (slag powder (SP)) =40:12:12:36; The optimum slurry ratio is 1:4 of binder/sand and 72% of concentration.

Research on the Volume Stability of Ternary Cementitious Systems Incorporating Fly Ash and Slag Powder

2009 ◽  
Vol 405-406 ◽  
pp. 256-261
Author(s):  
Hua Quan Yang ◽  
Shi Hua Zhou ◽  
Yun Dong
Keyword(s):  
Fly Ash ◽  
Ternary System ◽  
Cementitious Materials ◽  
Volume Shrinkage ◽  
Mineral Admixtures ◽  
High Quality ◽  
Volume Stability ◽  
Slag Powder ◽  
Cementitious Systems

The paper investigates the volume shrinkage of different cementitious materials. The results indicates the type and fineness of cement have significant effect on the volume stability of hardened paste, namely, the concrete with higher fineness cement has worse volume stability. The addition of mineral admixtures makes the volume stability of cementitious materials become complex. The mineral admixtures of high quality can reduce the shrinkage of hardened paste, and the duality system of cement incorporating fly ash have better volume stability than the ternary system of cement incorporating fly ash and slag powder.

scholarly journals Influence of boulder machine-made sand powder on compressive strength of concrete

2021 ◽  
Vol 293 ◽  
pp. 02023
Author(s):  
Pengtao Wang
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Early Stage ◽  
Cementitious Materials ◽  
Mineral Admixtures ◽  
Rock Powder ◽  
Manufactured Sand ◽  
Slag Powder ◽  
Compressive Strength Of Concrete ◽  
Curing Age

In order to recycle the boulder powder produced in the process of manufactured sand production and reduce the cost of engineering concrete, this article studied the influence of boulders powder on the compressive strength of concrete. The results show that in the early stage of concrete test, the compressive strength of rock powder concrete is slightly lower than of fly ash and mineral powder concrete. With the development of curing age, the strength of boulders powder concrete developed slower. As the increase of boulders powder content, the compressive strength of different curing age gradually decreased, and it was suggested that the content of boulders powder should be controlled within 20% of cementitious materials mass. The positive effect of boulders powder fineness on the strength of concrete is limited, so it is suggested to use unprocessed collected boulders powder in the project, which is economical and environmentally friendly. With the adjustment of water-to-binder ratio, boulders powder can be prepared with different strength grades of concrete to meet the needs of engineering; the composite of boulders powder with traditional mineral admixtures, such as fly ash, and especially granulated blast furnace slag powder, can significantly improve the strength of concrete.

scholarly journals Research on C30 Concrete Mix Proportion in Guangdong Province

2020 ◽  
Vol 213 ◽  
pp. 02039
Author(s):  
Guangxing Lai ◽  
Jianli Yin ◽  
Junhui Ye ◽  
Yujia Chen ◽  
Wei Xiao
Keyword(s):  
Guangdong Province ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Bleeding Rate ◽  
Slag Powder ◽  
Mix Proportion ◽  
Concrete Mix ◽  
Water Test ◽  
The Difference ◽  
Bleeding Water

The reasons of C30 concrete bleeding in winter in Guangdong province were studied by collecting the concrete mix proportions of C30 concrete mixing plants in Guangdong, Fujian, Henan, Hunan, Chongqing and Shaanxi regions, the difference between the concrete mix proportions in Guangdong and other regions was investigated. Based on the representative concrete mix proportion in Guangdong province, the concrete bleeding water test was carried out, and the correlation between the amount of different cementing materials and the bleeding rate was investigated. The results showed that compared with other regions, the C30 concrete mix proportion in Guangdong has the lowest total cementitious material, which made it more prone to bleeding. The amount of slag powder and the total amount of cementitious materials have a high correlation with the bleeding rate. With the increase of the amount of slag powder and the total amount of cementitious materials, the bleeding rate decreases.

scholarly journals Effect of Ferronickel Slag Powder on Microhydration Heat, Flow, Compressive Strength, and Drying Shrinkage of Mortar

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Bong-Suk Cho ◽  
Young-Uk Kim ◽  
Do-Bin Kim ◽  
Se-Jin Choi
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Heat Flow ◽  
Blast Furnace Slag ◽  
Drying Shrinkage ◽  
Cementitious Materials ◽  
Slag Powder ◽  
Ferronickel Slag ◽  
Furnace Slag ◽  
Nickel Industry

This paper investigates the effect of ferronickel slag powder on microhydration heat, flow, compressive strength, and drying shrinkage of mortar. In South Korea, approximately two million tons of ferronickel slag, a by-product of the nickel industry, are produced every year. However, a considerable amount of this by-product is treated as waste and dumped in landfills. Ferronickel slag powder was used to replace Portland cement at a ratio of 15% by binder mass. In addition, the mortar test with other cementitious materials, including blast-furnace slag powder and fly ash, was conducted and compared with the sample containing ferronickel slag powder. According to this investigation, the microhydration heat of mortar and concrete can be reduced with the appropriate use of ferronickel slag powder. In addition, in order to achieve higher concrete compressive strengths, it is apparently advantageous to use the ferronickel slag powder and fly ash together rather than using ferronickel slag powder alone.

scholarly journals Effect of Different Activators on Rheological and Strength Properties of Fly Ash-Based Filling Cementitious Materials

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Liu Fangfang ◽  
Feng Xiyang ◽  
Chen Li
Keyword(s):  
Fly Ash ◽  
Cementitious Materials ◽  
Strength Properties ◽  
Orthogonal Test ◽  
Activation Mechanism ◽  
Hydration Products ◽  
Cement Slurry ◽  
Hydration Degree ◽  
Bleeding Rate ◽  
Optimal Scheme

In this paper, lime, gypsum, NaOH, and Na2SO4 are mainly used to study the activation degree and activation mechanism of fly ash, and L9 (34) orthogonal table is used for the orthogonal test. The influence of different activators on the rheological and strength properties of slurry was analyzed. The microstructure and hydration products of fly ash cement cementitious body were studied by SEM and XRD. The results show that the bleeding rate of slurry containing activator fly ash system is between 2.24% and 3.37%, which is much higher than that of pure cement slurry (9.25%). Therefore, the addition of this system can improve the fluidity of slurry, and the optimal scheme is a3b2c2d2. The results show that the compressive strength of cement with activator fly ash system is much lower than that of pure cement, but the increase of strength is between 31% and 85%, which is much greater than that of pure cement (35%–46%). The optimal scheme is A2B2C3D3 or A3B2C3D3 at 3 days and A1B3C2D3 at 28 days. According to the scanning results of SEM and XRD, the addition of activator can significantly improve the hydration degree of fly ash and form a more complex network structure without obvious gap.

Effect of ground granulated blast funrnace slag and fly ash on strength, permeability, and under-water abrasion of fine-grained concrete

2020 ◽  
Vol 71 (7) ◽  
pp. 775-788
Author(s):  
Quyet Truong Van ◽  
Sang Nguyen Thanh
Keyword(s):  
Fly Ash ◽  
Concrete Strength ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Chloride Permeability ◽  
Cement Replacement ◽  
Fine Grained ◽  
Granulated Blast Furnace Slag ◽  
Compressive Strength Test ◽  
Economic Ground

The utilisation of supplementary cementitious materials (SCMs) is widespread in the concrete industry because of the performance benefits and economic. Ground granulated blast furnace slag (GGBFS) and fly ash (FA) have been used as the SCMs in concrete for reducing the weight of cement and improving durability properties. In this study, GGBFS at different cement replacement ratios of 0%, 20%, 40% and 60% by weight were used in fine-grained concrete. The ternary binders containing GGBFS and FA at cement replacement ratio of 60% by weight have also evaluated. Flexural and compressive strength test, rapid chloride permeability test and under-water abrasion test were performed. Experimental results show that the increase in concrete strength with GGBFS contents from 20% to 40% but at a higher period of maturity (56 days and more). The chloride permeability the under-water abrasion reduced with the increasing cement replacement by GGBFS or a combination of GGBFS and FA

scholarly journals Effect of fly ash on the self-healing capability of cementitious materials with crystalline admixture under different conditions

AIP Advances ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 075018
Author(s):  
Xi Wang ◽  
Hao Qiao ◽  
Ziwei Zhang ◽  
Shiying Tang ◽  
Shengjun Liu ◽  
...  
Keyword(s):  
Fly Ash ◽  
Cementitious Materials ◽  
The Self ◽  
Self Healing

scholarly journals New Approach for the Determination of Radiological Parameters on Hardened Cement Pastes with Coal Fly Ash

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 475
Author(s):  
Ana María Moreno de los Reyes ◽  
José Antonio Suárez-Navarro ◽  
Maria del Mar Alonso ◽  
Catalina Gascó ◽  
Isabel Sobrados ◽  
...  
Keyword(s):  
Fly Ash ◽  
Activity Concentration ◽  
Gamma Ray ◽  
Coal Fly Ash ◽  
Cementitious Materials ◽  
New Method ◽  
Supplementary Cementitious Materials ◽  
Hardened Cement ◽  
Cement Pastes ◽  
Activity Concentrations

Supplementary cementitious materials (SCMs) in industrial waste and by-products are routinely used to mitigate the adverse environmental effects of, and lower the energy consumption associated with, ordinary Portland cement (OPC) manufacture. Many such SCMs, such as type F coal fly ash (FA), are naturally occurring radioactive materials (NORMs). 226Ra, 232Th and 40K radionuclide activity concentration, information needed to determine what is known as the gamma-ray activity concentration index (ACI), is normally collected from ground cement samples. The present study aims to validate a new method for calculating the ACI from measurements made on unground 5 cm cubic specimens. Mechanical, mineralogical and radiological characterisation of 28-day OPC + FA pastes (bearing up to 30 wt % FA) were characterised to determine their mechanical, mineralogical and radiological properties. The activity concentrations found for 226Ra, 212Pb, 232Th and 40K in hardened, intact 5 cm cubic specimens were also statistically equal to the theoretically calculated values and to the same materials when ground to a powder. These findings consequently validated the new method. The possibility of determining the activity concentrations needed to establish the ACI for cement-based materials on unground samples introduces a new field of radiological research on actual cement, mortar and concrete materials.

scholarly journals Effect of Fly Ash on Compressive Strength, Drying Shrinkage, and Carbonation Depth of Mortar with Ferronickel-Slag Powder

2021 ◽  
Vol 11 (3) ◽  
pp. 1037
Author(s):  
Se-Jin Choi ◽  
Ji-Hwan Kim ◽  
Sung-Ho Bae ◽  
Tae-Gue Oh
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Construction Industry ◽  
Bituminous Coal ◽  
Raw Materials ◽  
Drying Shrinkage ◽  
The Other ◽  
Test Results ◽  
Slag Powder ◽  
Ferronickel Slag

In recent years, efforts to reduce greenhouse gas emissions have continued worldwide. In the construction industry, a large amount of CO2 is generated during the production of Portland cement, and various studies are being conducted to reduce the amount of cement and enable the use of cement substitutes. Ferronickel slag is a by-product generated by melting materials such as nickel ore and bituminous coal, which are used as raw materials to produce ferronickel at high temperatures. In this study, we investigated the fluidity, microhydration heat, compressive strength, drying shrinkage, and carbonation characteristics of a ternary cement mortar including ferronickel-slag powder and fly ash. According to the test results, the microhydration heat of the FA20FN00 sample was slightly higher than that of the FA00FN20 sample. The 28-day compressive strength of the FA20FN00 mix was approximately 39.6 MPa, which was higher than that of the other samples, whereas the compressive strength of the FA05FN15 mix including 15% of ferronickel-slag powder was approximately 11.6% lower than that of the FA20FN00 mix. The drying shrinkage of the FA20FN00 sample without ferronickel-slag powder was the highest after 56 days, whereas the FA00FN20 sample without fly ash showed the lowest shrinkage compared to the other mixes.

Test and Study on Green High-Performance Marine Concrete Containing Ultra-Fine Limestone Powder

2013 ◽  
Vol 368-370 ◽  
pp. 1112-1117
Author(s):  
Jin Hui Li ◽  
Liu Qing Tu ◽  
Ke Xin Liu ◽  
Yun Pang Jiao ◽  
Ming Qing Qin
Keyword(s):  
Fly Ash ◽  
High Performance ◽  
Mechanical Performance ◽  
Chloride Ion ◽  
Limestone Powder ◽  
Ion Permeability ◽  
High Quality ◽  
Cracking Resistance ◽  
Slag Powder ◽  
Marine Concrete

In order to solve the environment pollution of limestone powder during production of limestone manufactured sand and gravel and problem of lack of high quality fly ash or slag powder in ocean engineering, ultra-fine limestone powder was selected for preparation of green high-performance marine concrete containing fly ash and limestone powder and that containing slag powder and limestone powder for tests on workability, mechanical performance, thermal performance, shrinkage, and resistance to cracking and chloride ion permeability. And comparison was made between such green high-performance concrete and conventional marine concrete containing fly ash and slag powder. Moreover, the mechanism of green high-performance marine concrete was preliminary studied. Results showed that ultra-fine limestone powder with average particle size around 10μm had significant water reducing function and could improve early strength of concrete. C50 high-performance marine concrete prepared with 30% fly ash and 20% limestone powder or with 30% slag powder and 30% limestone powder required water less than 130kg/m3, and showed excellent workability with 28d compressive strength above 60MPa, 56d dry shrinkage rate below 300με, cracking resistance of grade V, 56d chloride ion diffusion coefficient not exceeding 2.5×10-12m2/s. Mechanical performance and resistance to chloride ion permeability of limestone powder marine concrete were quite equivalent to those of conventional marine concrete. But it had better workability, volume stability and cracking resistance. Moreover, it can serve as a solution to the lack of high quality fly ash and slag powder.

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