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.

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.

Effects of Mineral Admixtures and Superplasticizer on Controlling Hydration Heat of Cementitious Materials

2013 ◽  
Vol 639-640 ◽  
pp. 368-371
Author(s):  
Qing Huang ◽  
Jian Yin ◽  
Wei Min Song
Keyword(s):  
Fly Ash ◽  
Release Rate ◽  
Early Stage ◽  
Cementitious Materials ◽  
Heat Evolution ◽  
Hydration Heat ◽  
Mineral Admixtures ◽  
Evolution Rate ◽  
Two Parameters ◽  
Peak Value

The effects of mineral admixtures and superplasticizer on reducing the hydration heat of cementitious material were evaluated in this study, and the heat evolution rate and hydration heat were tested as the two parameters to evaluate the effect of improvement. The results showed that the cement partly-replaced with fly ash (FA) and slag (SG) could significantly decrease the release rate of hydration heat on the early stage of hydration, and lower the peak value of the heat evolution rate. The superplasticizer (TJ-Ⅲ) could reduce the hydration heat mainly on the early stage of hydration, and extended the induction period. In comparison with slag, the fly ash had more active effects on reducing the peak value and release rate of hydration heat.

Pulse Velocity Measurements in Fly Ash Blended Cementitious Systems Containing 43 Grade Cement

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
V. M. Sounthararajan ◽  
A. Sivakumar
Keyword(s):  
Fly Ash ◽  
Cost Savings ◽  
Ultrasonic Pulse Velocity ◽  
Cementitious Materials ◽  
Ultrasonic Pulse ◽  
Pozzolanic Reaction ◽  
Pulse Velocity ◽  
Supplementary Cementitious Materials ◽  
Pozzolanic Material ◽  
Cementitious Systems

Investigations on the different supplementary cementitious materials based on the hardening properties and the optimized dosage in cementitious systems find the right choice of pozzolanic material. It is essential to combine various additive/admixtures in concrete in proper proportions to maximize the benefits resulting in cost savings in construction. In the recent years, production technology and composition of hydraulic cements affect the setting and early age behavior of cementitious material. The addition of fly ash in cement is one viable technology to derive maximum benefits in terms of the economy and improved pozzolanic reaction. Ultrasonic pulse velocity testing is a feasible method for evaluating the hardening properties of cementitious materials. In this study, an attempt was made to derive the engineering basis for understanding the development of hardness during hydration of fly ash (FA) based cementitious systems. The tests conducted using pulse velocity technique proved to be an effective method for characterizing the early strength gain properties of different cementitious systems.

Effect of steel slag powder, fly ash, and silica fume on the mechanical properties and durability of cement mortar

2019 ◽  
Vol 9 (9) ◽  
pp. 1049-1054
Author(s):  
Yunxia Lun ◽  
Fangfang Zheng
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Cement Mortar ◽  
Steel Slag ◽  
Mineral Admixtures ◽  
Partial Replacement ◽  
Slag Powder ◽  
Steel Slag Powder

This study is aimed at exploring the effect of steel slag powder (SSP), fly ash (FA), and silica fume (SF) on the mechanical properties and durability of cement mortar. SSP, SF, and FA were used as partial replacement of the Ordinary Portland cement (OPC). It was showed that the compressive and bending strength of steel slag powder were slightly lower than that of OPC. An increase in the SSP content caused a decrease in strength. However, the growth rate of compressive strength of SSP2 (20% replacement by the weight of OPC) at the curing ages of 90 days was about 8% higher than that of OPC, and the durability of SSP2 was better than that of OPC. The combination of mineral admixtures improved the later strength, water impermeability, and sulfate resistance compared with OPC and SSP2. The compressive strength of SSPFA (SSP and SF) at 90 days reached 70.3 MPa. The results of X-ray diffraction patterns and scanning electron microscopy indicated that SSP played a synergistic role with FA or SF to improve the performance of cement mortar.

COMPARATIVE INVESTIGATION OF STRENGTH PROPERTIES OF CONCRETE MIXED WITH VARIOUS POWDER AS ALTERNATIVE CEMENTITIOUS MATERIALS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Isamu Yoshitake ◽  
Keisuke Miyamoto ◽  
Jun Mizushima ◽  
Kurumi Yamamoto ◽  
Koichiro Yamato
Keyword(s):  
Concrete Strength ◽  
Cementitious Materials ◽  
Comparative Investigation ◽  
Strength Properties ◽  
Cementitious Material ◽  
Limestone Powder ◽  
Mineral Admixtures ◽  
Powder Materials ◽  
Slag Powder ◽  
Chloride Resistance

Mineral admixtures are often mixed in concrete as an alternative cementitious material. The use of powder materials indirectly contributes to mitigation of environmental impact caused from Portland cement production which is a major source of CO2 emission. Furthermore, some of powder can improve properties of fresh and hardened concretes. A huge number of reports examining effects of admixture have been published in the world. However, it is not easy to compare the effect of admixture under a certain test condition. The present study aims to examining strength properties of concrete incorporating various admixtures. All admixtures tested herein were mixed in concrete as an alternative cementitious material, and the cement replacement ratios were in the range of 0.2 to 0.6. The tested powder materials are limestone powder, fly-ash, blast furnace slag powder, silica-fume, and inorganic admixture which was recently developed to increase chloride resistance. The focus of the study is to quantify the effect of these admixture on concrete strength. The paper reports compressive, split tensile and flexural strengths of these concretes, and discusses the effect of powder materials.

Workability and Mechanical Properties of Concret with Different Admixtures

2013 ◽  
Vol 325-326 ◽  
pp. 67-70
Author(s):  
Yun Feng Li ◽  
Mi Xue Han ◽  
Li Xu
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Fly Ash ◽  
Blast Furnace Slag ◽  
Steel Slag ◽  
Mineral Admixtures ◽  
Slag Powder ◽  
Steel Slag Powder ◽  
Furnace Slag

The mineral admixtures mixed into concrete have important effects on concrete performance. The workability and mechanical properties of the concrete are studied with different dosages of admixtures, such as steel slag powder, blast furnace slag powder and fly ash. The results show that fly ash has more advantages in improving the performance of the concrete. When steel slag powder, blast furnace slag powder and fly ash, respectively, replace the amount of cement to 30%, 30%, 20%, the mechanical properties of the concrete are improved significantly.

Study on the Hydration Micro-Structure and Properties of Complex Cementitious Systems

2010 ◽  
Vol 150-151 ◽  
pp. 783-787
Author(s):  
Qing Jun Ding ◽  
Xiu Lin Huang ◽  
Hua Sun
Keyword(s):  
Fly Ash ◽  
Pore Size Distribution ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Structure And Properties ◽  
Total Dosage ◽  
Micro Structure ◽  
Cement Pastes ◽  
Cementitious Systems ◽  
Better Than

In this study complex cementitious systems were prepared by cement, slag, fly ash and silica fume. Changing the dosages of mineral admixtures, then studying the strength and micro-structure of harden cement pastes by XRD,SEM,BET etc. Comparing the influence of variety and dosage of mineral admixture on cement pastes.Finally we found that mineral admixtures could improve the pore size distribution of cement pastes, and the total dosage 10% is better than 20%; and the "FA+SF" is better than others.

Orthogonal Test of Characteristics of Complex Cememting Material of FGD Gypsum-Fly Ash

2011 ◽  
Vol 250-253 ◽  
pp. 460-463
Author(s):  
Yi Zhang ◽  
Xin Tang Wang ◽  
Ming Zhou ◽  
Wan Zhen Wang
Keyword(s):  
Fly Ash ◽  
Orthogonal Test ◽  
Test Method ◽  
Experimental Results ◽  
Mineral Admixtures ◽  
Fgd Gypsum ◽  
Slag Powder ◽  
Mix Proportion ◽  
Orthogonal Test Method ◽  
Cementing Material

Orthogonal test method is used to study the effect of the mineral admixtures on the performance of FGD gypsum-fly ash complex cementing material. On the basic experiment, the effect of the traditional alkali and salt admixtures added to the complex cementitious system is discussed, the factors effecting on performance of the FGD gypsum were analyzed. Based on the experimental results, the best mix proportion was determined. Finally, the basic performance of complex cementitious material was tested. The experimental results show that the performance of FGD gypsum which is activated through adding the compound admixtures was similar with the ordinary interior wall materials. The strength and water resistance of FGD gypsum complex cementing material can be greatly enhanced by adding cement, quicklime and slag powder, and effect of cement is largest, and slag smallest. The performance of the gypsum complex cementing material also can be improved after incorporation of a few of chemical admixture on the basis of adding mineral activators.

scholarly journals Circulating Fluidized Bed Fly Ash Mixed Functional Cementitious Materials: Shrinkage Compensation of f-CaO, Autoclaved Hydration Characteristics and Environmental Performance

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6004
Author(s):  
Wei Zhang ◽  
Xiaoming Liu ◽  
Zengqi Zhang ◽  
Yaguang Wang ◽  
Yang Xue ◽  
...  
Keyword(s):  
Fly Ash ◽  
Fluidized Bed ◽  
Environmental Performance ◽  
Circulating Fluidized Bed ◽  
Standard Condition ◽  
Cementitious Materials ◽  
Charge Balance ◽  
Volume Stability ◽  
Shrinkage Compensation ◽  
Hydration Characteristics

Circulating fluidized bed (CFB) fly ash is a by-product from CFB power generation, which is hard to utilize in cement because it contains f-CaO and SO3. This work aims to explore the mechanism of the shrinkage compensation of free-CaO (f-CaO) and the autoclaved hydration characteristics and environmental performance of CFB fly ash mixed cementitious materials (CMM). In this work, long-term volume stability of CMM is improved with the addition of CFBFA. These findings suggest that the compressive strength of sample CMM0.5 is the highest under both standard condition (67.21 MPa) and autoclaved condition (89.56 MPa). Meanwhile, the expansion rate (0.0207%) of sample CMM0.5 is the lowest, which proves the shrinkage compensation effect of f-CaO in CFBFA. The main hydration products of CMM0.5 are Ca2SiO4•H2O (C-S-H) gel, CaAl2Si2O7(OH)2•H2O (C-A-S-H) gel and Ca(OH)2. In addition, the high polymerization degree of [Si(Al)O4] and the densified microstructure are presented at the sample CMM0.5. The leaching results indicates that the heavy metals in CMM0.5 satisfies the WHO standards for drinking water due to physical encapsulation and charge balance. Therefore, this investigation provides a novel method of using CFB fly ash in cement.

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