Influence of Limestone Powder on the Hydration of Cement-Steel Slag Composite Binder

2014 ◽  
Vol 988 ◽  
pp. 226-229
Author(s):  
Mu Tian Liu ◽  
Jin Hu ◽  
Ying Jun Mei
Keyword(s):  
Compressive Strength ◽  
Steel Slag ◽  
Hydration Heat ◽  
Limestone Powder ◽  
Mineral Admixtures ◽  
Hydration Products ◽  
Early Hydration ◽  
Composite Binder ◽  
Negative Effect ◽  
Positive Effect

Steel slag and limestone powder are both mineral admixtures for cement or concrete. Steel slag can react with water and produce hydration products. The hydration activity of limestone powder is very limited. This paper investigated the influence of limestone powder on the hydration of cement-steel slag composite binder by determining the hydration heat and compressive strength. The results show that limestone powder can promote the early hydration of the composite binder and the compressive strength of mortar increases by replacing part of steel slag by limestone powder. However, at the age of 28 days, the positive effect of limestone powder is almost equal to its negative effect, so the compressive strength of mortar changes little by replacing part of steel slag by limestone powder.

scholarly journals Study on Strength and Microstructure of Cement-Based Materials Containing Combination Mineral Admixtures

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Meijuan Rao ◽  
Jianpeng Wei ◽  
Zhiyang Gao ◽  
Wei Zhou ◽  
Qiaoling Li ◽  
...  
Keyword(s):  
Testing Machine ◽  
Steel Slag ◽  
Pozzolanic Reaction ◽  
Mineral Admixture ◽  
Limestone Powder ◽  
Mineral Admixtures ◽  
Strength Development ◽  
Hydration Products ◽  
Cement Based Materials ◽  
Aggregate Effect

The compressive strength of complex binders containing two or three blended mineral admixtures in terms of glass powder (GP), limestone powder (LP), and steel slag powder (SP) was determined by a battery solution type compressive testing machine. The morphology and microstructure characteristics of complex binder hydration products were also studied by microscopic analysis methods, such as XRD, TG-DTA, and SEM. The mechanical properties of the cement-based materials were analyzed to reveal the most appropriate mineral admixture type and content. The early sample strength development with GP was very slow, but it rapidly grew at later stages. The micro aggregate effect and pozzolanic reaction mutually occurred in the mineral admixture. In the early stage, the micro aggregate effect reduced paste porosity and the small particles connected with the cement hydration products to enhance its strength. In the later stage, the pozzolanic reaction of some components in the complex powder occurred and consumed part of the calcium hydroxide to form C-S-H gel, thus improving the hydration environment. Also, the produced C-S-H gel made the structure more compact, which improved the structure’s strength.

scholarly journals Artificial Neural Network Estimation of the Effect of Varying Curing Conditions and Cement Type on Hardened Concrete Properties

Buildings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 10 ◽  
Author(s):  
Gökhan Kaplan ◽  
Hasbi Yaprak ◽  
Selçuk Memiş ◽  
Abdoslam Alnkaa
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Limestone Powder ◽  
Mineral Admixtures ◽  
Hardened Concrete ◽  
Slag Cement ◽  
Curing Conditions ◽  
Concrete Properties ◽  
Concrete Production ◽  
Artificial Neural

The use of mineral admixtures and industrial waste as a replacement for Portland cement is recognized widely for its energy efficiency along with reduced CO2 emissions. The use of materials such as fly ash, blast-furnace slag or limestone powder in concrete production makes this process a sustainable one. This study explored a number of hardened concrete properties, such as compressive strength, ultrasonic pulse velocity, dynamic elasticity modulus, water absorption and depth of penetration under varying curing conditions having produced concrete samples using Portland cement (PC), slag cement (SC) and limestone cement (LC). The samples were produced at 0.63 and 0.70 w/c (water/cement) ratios. Hardened concrete samples were then cured under three conditions, namely standard (W), open air (A) and sealed plastic bag (B). Although it was found that the early-age strength of slag cement was lower, it was improved significantly on 90th day. In terms of the effect of curing conditions on compressive strength, cure W offered the highest compressive strength, as expected, while cure A offered slightly lower compressive strength levels. An increase in the w/c ratio was found to have a negative impact on pozzolanic reactions, which resulted in poor hardened concrete properties. Furthermore, carbonation effect was found to have positive effects on some of the concrete properties, and it was observed to have improved the depth of water penetration. Moreover, it was possible to estimate the compressive strength with high precision using artificial neural networks (ANN). The values of the slopes of the regression lines for training, validating and testing datasets were 0.9881, 0.9885 and 0.9776, respectively. This indicates the high accuracy of the developed model as well as a good correlation between the predicted compressive strength values and the experimental (measured) ones.

scholarly journals Effects of Expansive Agents on the Early Hydration Kinetics of Cementitious Binders

Materials ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 1900 ◽  
Author(s):  
Miao Miao ◽  
Qingyang Liu ◽  
Jian Zhou ◽  
Jingjing Feng
Keyword(s):  
Fly Ash ◽  
Hydration Heat ◽  
Mineral Admixture ◽  
Mineral Admixtures ◽  
Hydration Reaction ◽  
Hydration Kinetics ◽  
Early Hydration ◽  
Expansive Agent ◽  
Mechanical Performances ◽  
Kinetics Of

The addition of expansive agents could overcome the main disadvantages of raw concrete including high brittleness and low tensile strength. Few studies have investigated the early hydration kinetics of expansive cementitious binders, though the findings from the early hydration kinetics are helpful for understanding their technical performances. In this study, mixtures of 3CaO•3Al2O3•CaSO4 and CaSO4 (i.e., ZY-type™ expansive agent) with different proportions of mineral admixtures (e.g., fly ash and slag) were added into cement pastes to investigate the early hydration kinetics mechanism of expansive cementitious binders. Early hydration heat evolution rate and cumulative hydration heat were measured by isothermal calorimeter. Kinetic parameters were estimated based on the Krstulovic–Dabic model and Knudsen equations. Mechanical performances of expansive cementitious binders were tested in order to evaluate if they met the basic requirements of shrinkage-compensating materials in technical use. The early hydration heat released from cementitious binders containing ZY-type™ expansive agent was much greater than that released by pure cement, supporting the idea that addition of the expansive agent would improve the reaction of cement. The early hydration kinetic rates were decreased due to the reactions of the mineral admixture (e.g., fly ash or slag) and the ZY-type™ expansive agent in the cement system. The hydration reaction of cementitious binders containing ZY-type™ expansive agent obeyed the Krstulovic–Dabic model well. Three processes are involved in the hydration reaction of cementitious binders containing ZY-type™ expansive agent. These are nucleation and crystal growth (NG), interactions at phase boundaries (I), and diffusion (D). The 14-day expansion rates of cementitious binders containing ZY-type™ expansive agent are in the range of 2.0 × 10−4 to 3.5 × 10−4, which could meet the basic requirements of anti-cracking performances in technical use according to Chinese industry standard JGJ/T 178-2009. This study could provide an insight into understanding the effects of expansive agents on the hydration and mechanical performances of cementitious binders.

Mechanical Properties of Concretes Containing Super-Fine Mineral Admixtures

2012 ◽  
Vol 174-177 ◽  
pp. 1406-1409 ◽  
Author(s):  
Hong Fang Li ◽  
Li Guo ◽  
Yi Xia
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Limestone Powder ◽  
Mineral Admixtures ◽  
Compression Tests ◽  
Titanium Slag ◽  
Lithium Slag ◽  
Powder Titanium

The mechanical properties of concretes containing super fine mineral admixtures such as limestone powder, titanium slag, lithium slag and silica ash have been investigated by compression tests. It was found that 10% limestone powder used in cocncrete is beneficial to compressive strength, it reaches 111Mpa after 28 days curing. The optimum mixing amounts of titanium slag, lithium slag and silica ash are 20%, 10% and 10%, respectively. All their 28d compressive strengths exceed 100MPa, reach super-early and super-high strength concrete level. By introducing mineral admixures into concrete, the cement consumption in concrete can be greatly reduced.

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.

The Influence of Combined Admixture of Super-Fine Limestone Powder and Low-Quality Fly Ash on the Performance of Cement Mortar

2013 ◽  
Vol 652-654 ◽  
pp. 1181-1184
Author(s):  
Guo Qiang Xu ◽  
Zhi Guo You ◽  
Lin Gao ◽  
Dian Li Han
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Flexural Strength ◽  
Cement Mortar ◽  
Limestone Powder ◽  
Mineral Admixtures ◽  
Test Results ◽  
Maximum Compressive Strength

The influence of admixture of super-fine limestone powder and low-quality fly ash in different proportions on the fluidity and strength of cement mortar is studied. The test results show that the mortar fluidity increases with the increase of the super-fine limestone powder (the mixing amount of fly ash reduces), and the strength of cement mortar can improve when limestone powder and low-quality fly ash are combined admixed to a certain ratio. The maximum flexural strength of the 28d mortar is 9.8MPa and its maximum compressive strength is 42.2MPa, and at this time, the limestone powder accounts for 33.3% of the mineral admixtures. However, when the mixing amount of super-fine limestone powder is over a certain range, the strength of 28d cement mortar will reduce.

scholarly journals The use of non-destructive tests to estimate Self-compacting concrete compressive strength

2018 ◽  
Vol 149 ◽  
pp. 01036
Author(s):  
Boukhelkhal Djamila ◽  
Guendouz Mohamed
Keyword(s):  
Compressive Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Mineral Admixture ◽  
Limestone Powder ◽  
Mineral Admixtures ◽  
Self Compacting Concrete ◽  
Correlation Relationship ◽  
Granulated Slag

Until now, there are few studies on the effect of mineral admixtures on correlation between compressive strength and ultrasonic pulse velocity for concrete. The aim of this work is to study the effect of mineral admixture available in Algeria such as limestone powder, granulated slag and natural pozzolana on the correlation between compressive strength and corresponding ultrasonic pulse velocity for self-compacting concrete (SCC). Compressive strength and ultrasonic pulse velocity (UPV) were determined for four different SCC (with and without mineral admixture) at the 3, 7, 28 and 90 day curing period. The results of this study showed that it is possible to develop a good correlation relationship between the compressive strength and the corresponding ultrasonic pulse velocity for all SCC studied in this research and all the relationships had exponential form. However, constants were different for each mineral admixture type; where, the best correlation was found in the case of SCC with granulated slag (R2 = 0.85). Unlike the SCC with pozzolana, which have the lowest correlation coefficient (R2 = 0.69).

Study on the Desulfurization Gypsum and Steel Slag Blended Clinker-Free Cementing Material

2012 ◽  
Vol 193-194 ◽  
pp. 384-388
Author(s):  
Hai Liang Luo ◽  
Chun Sheng Li ◽  
Yi Ting Ye ◽  
Fu Dan Chen
Keyword(s):  
Setting Time ◽  
Steel Slag ◽  
Orthogonal Test ◽  
Raw Material ◽  
Water Quantity ◽  
Hydration Products ◽  
Early Hydration ◽  
Mix Proportion ◽  
Cementing Material ◽  
Micro Analysis

Based on orthogonal test with steel slag and desulfurization gypsum as main raw material, mixed appropriate amount slag and compound addition a little of activator, we explored the slag dosage, the proportion of the combined admixture activator and the desulfurization gypsum dosage impact on the performance of clinker-free cementing material, such as strength, stability, standard consistency water quantity and setting time. The results showed that the best mix proportion of cementing material with slag content 40% and activator A:activator B is equal to 2.78:2.22. We explored the structure and composition of hydration products further more by micro-analysis, such as SEM, EDS and so on. We can found that the cementing material hydration products similar with hydration products of silicate cement. The cementitious material hydration with Afm crystal content increased significantly. The Aft crystal generated in early hydration(3d) gradually transformed into Afm crystal in late hydration(28d) ,and the structure becomes more dense.

scholarly journals The Role of Phosphorus Slag in Steam-Cured Concrete

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Jin Liu ◽  
Dongmin Wang
Keyword(s):  
Pore Structure ◽  
Water Content ◽  
Hydration Heat ◽  
Curing Temperature ◽  
Hydration Products ◽  
Hydration Degree ◽  
Steam Curing ◽  
Chloride Permeability ◽  
Early Hydration

Steam curing is an effective method to increase the hydration degree of binder containing phosphorus slag. The role of phosphorus slag in steam-cured concrete was investigated by determining the hydration heat, hydration products, nonevaporable water content, pore structure of paste, and the compressive strength and chloride ion permeability of concrete. The results show that elevated steam curing temperature does not lead to new crystalline hydration products of the composite binder containing phosphorus slag. Elevating steam curing temperature enhances the early hydration heat and nonevaporable water content of the binder containing phosphorus slag more significantly than increasing steam curing time, and it also results in higher late-age hydration degree and finer pore structure. For steam-cured concrete containing phosphorus slag, elevating curing temperature from 60°C to 80°C tends to decrease the late-age strength and increase the chloride permeability. However, at constant curing temperature of 60°C, the steam-cured concrete containing phosphorus slag can achieve satisfied demoulding strength and late-age strength and chloride permeability by extending the steam curing duration.

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