Cementitious Activity Evaluation of Steel Slag by EDTA-NaOH Solution Extraction Method

2017 ◽  
Vol 893 ◽  
pp. 389-394
Author(s):  
Zai Bo Li ◽  
Tu Sheng He ◽  
Xu Guang Zhao ◽  
San Yin Zhao
Keyword(s):  
Compressive Strength ◽  
Extraction Method ◽  
Evaluation Method ◽  
Steel Slag ◽  
Rapid Evaluation ◽  
Mortar Strength ◽  
Extraction Test ◽  
Naoh Solution ◽  
Cementitious Activity ◽  
The Relationship

In order to establish a rapid evaluation method of steel slag cementitious activity, extraction test of steel slag in EDTA-NaOH solution have been investigated and the relationship between extraction characteristics and cementitious activity expressed as mortar strength has been analyzed. Results show that the linear relationship between the quantity extracted from steel slag and the mortar compressive strength is significant. According to the analysis results of mineral composition and microscopic morphologies, EDTA-NaOH solution can selectively extract the silicate and aluminate minerals of steel slag, which could be used as a rapid evaluation method of steel slag cementitious activity.

Effect of Chemical Composition on the Properties of Reconstructed Steel Slag

2019 ◽  
Vol 944 ◽  
pp. 1163-1171
Author(s):  
Ying Xu ◽  
Qiao Ling Wang ◽  
Chen Guang Hu ◽  
Shan Shan Yang
Keyword(s):  
Compressive Strength ◽  
Steel Slag ◽  
Temperature Reconstruction ◽  
X Ray Diffraction ◽  
Technological Parameters ◽  
Iron And Steel ◽  
X Ray ◽  
Volume Stability ◽  
Cementitious Activity ◽  
Scanning Electron

The steel slag is not widely or extensively used because of its poor volume stability and low cementitious activity. In this paper, the solid waste fly ash, quicklime and slag discharged from iron and steel enterprises are used as conditioning components in the experiment. In order to improve the cementitious activity and volume stability of steel slag, the high temperature reconstruction experiment of steel slag was completed. The effects of C/S (2.50~3.14), S/A (4.5~17. 81) on the cementitious activity and volume stability of reconstructed steel slag were investigated by means of the tests of compressive strength, scanning electron microscope, X-ray diffraction, lithofacies test, stability test and so on. The results showed that the cementitious activity and volume stability of the reconstructed steel slag were improved in the higher C/S or lower S/A. The cementitious activity and volume stability of the reconstructed steel slag were improved with the increase of CaF2 content. By analyzing the cementitious activity and volume stability of the reconstructed steel slag, the optimum technological parameters are obtained as follows: C/S is 2.70 , S/A is 5.78, the content of CaF2 is 4%.

The Relationship of NaOH Molarity, Na2SiO3/NaOH Ratio, Fly Ash/Alkaline Activator Ratio, and Curing Temperature to the Strength of Fly Ash-Based Geopolymer

2011 ◽  
Vol 328-330 ◽  
pp. 1475-1482 ◽  
Author(s):  
M. M. A. Abdullah ◽  
H. Kamarudin ◽  
M. Bnhussain ◽  
I. Khairul Nizar ◽  
A.R. Rafiza ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Construction Industry ◽  
Curing Temperature ◽  
Test Results ◽  
Compression Tests ◽  
Naoh Solution ◽  
Alkaline Activator ◽  
Relationship Of ◽  
The Relationship

Geopolymer, produced by the reaction of fly ash with an alkaline activator (mixture of Na2SiO3 and NaOH solutions), is an alternative to the use of ordinary Portland cement (OPC) in the construction industry. However, there are salient parameters that affecting the compressive strength of geopolymer. In this research, the effects of various NaOH molarities, Na2SiO3/NaOH ratios, fly ash/alkaline activator, and curing temperature to the strength of geopolymer paste fly ash were studied. Tests were carried out on 50 x 50 x 50 mm cube geopolymer specimens. Compression tests were conducted on the seventh day of testing for all samples. The test results revealed that a 12 M NaOH solution produced the highest compressive strength for the geopolymer. The combination mass ratios of fly ash/alkaline activator and Na2SiO3/NaOH of 2.0 and 2.5, respectively, produced the highest compressive strength after seven days. Geopolymer samples cured at 60 °C produced compressive strength as high as 70 MPa.

scholarly journals Evaluation Method for Thixotropy of Clay Subjected to Unconfined Compressive Test

2021 ◽  
Vol 9 ◽  
Author(s):  
Bin Tang ◽  
Biaohe Zhou ◽  
Liang Xie ◽  
Jianfeng Yin
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Evaluation Method ◽  
Curing Time ◽  
Recovery Coefficient ◽  
Undisturbed Soil ◽  
Structural Recovery ◽  
The Index System ◽  
The Relationship

Thixotropy is a hot topic in the field of rheology of dispersed systems. Studying the quantitative index and evaluation method for thixotropy of clay is of great significance to evaluate the safety of foundation under long-term load. To explore the index system and classification methods for the thixotropy of clay, unconfined compressive strength tests were carried out on three groups of undisturbed soil and remolded soil that were cured at different times after remodeling of the Zhanjiang Formation in China to obtain the unconfined compressive strength values of the samples and establish the relationship between unconfined compressive strength and curing time of the remodeled soil. The concept of thixotropic sensitivity is introduced to reflect the relationship between thixotropy and structure. According to the relationship between thixotropy sensitivity and curing time and its logarithmic value, two indexes of structural recovery coefficient K and structural recovery index Ke were established to evaluate the thixotropy of structural clay in the Zhanjiang Formation. Following the structural classification method of soil, the boundary values of structural recovery coefficients KI and KII are calculated to classify the thixotropy of soil. When the value of K is less than that of KI, the thixotropy of soil is weak. When the value of K is greater than that of K but less than that of KII, the thixotropy of soil is moderate. When the value of K is greater than that of KII, the thixotropy of soil is strong. The method is used to discuss the thixotropy of soil in the literature, and the rationality of the method is verified. Results show that this method can be used to preliminary classify the thixotropy of soil.

Influence of Fineness and Vontent of Steel Slag Powder on Properties of Composite Admixture

2020 ◽  
Vol 996 ◽  
pp. 117-122
Author(s):  
Tu Sheng He ◽  
Yang Xu ◽  
Yang Liu ◽  
Zai Bo Li ◽  
San Yin Zhao ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Regression Analysis ◽  
Steel Slag ◽  
Contour Map ◽  
Slag Powder ◽  
Performance Indexes ◽  
Steel Slag Powder ◽  
Cementitious Activity ◽  
Map Analysis ◽  
Good Agreement

Taking fluidity and compressive strength of mortar as index, steel slag slag composite admixture replaces cement by 50%. The influence of the fineness and content of steel slag powder on the properties of composite admixture was studied by uniform experimental design. The fitting regression equation between the parameters of steel slag fineness and dosage and the performance indexes is established, and the contour map is drawn. The results show that the predicted value is in good agreement with the measured value, and the correlation coefficient is more than 0.99. Through regression analysis and contour map analysis, it is shown that increasing the fineness of slag powder and reducing the content of slag are beneficial to improving the cementitious activity of slag composite.

scholarly journals Effect of Al2O3–SiO2 Addition on Gehlenite Growth and the Mechanical Performance of Steel Slag

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 936
Author(s):  
Ying Xu ◽  
Pan Song ◽  
Weigang Cao ◽  
Hui Li ◽  
Jinglong Liang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Mechanical Performance ◽  
Steel Slag ◽  
Phase Changes ◽  
Morphology Evolution ◽  
Industrial Solid Waste ◽  
Increasing Temperature ◽  
Relationship Of ◽  
The Relationship

Steel slag, as industrial solid waste, is difficult to recycle owing to its complex components and poor mechanical properties. However, steel slag can be modified by adding Al2O3–SiO2 through high temperature sintering, which would improve the mechanical properties and expand the scope of its application. The phase changing, morphology evolution and the mechanical properties of the modified steel slag were investigated. The results indicate that the main phase changes to gehlenite occur with increasing temperature. The compressive strength increases to 115 MPa at 1350 °C. The relationship of the quantity of gehlenite and the compressive strength were explored.

Microstructure, Mineral Phases and Strength of the Foam Concrete

2011 ◽  
Vol 492 ◽  
pp. 484-488 ◽  
Author(s):  
Xin Gang Yu ◽  
Shi Song Luo ◽  
Yan Na Gao ◽  
Huaan Xiao ◽  
De Jun Li ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Steel Slag ◽  
Curing Time ◽  
Foam Concrete ◽  
Strength Of Materials ◽  
Mineral Phases ◽  
Materials Research ◽  
The Relationship

The relationship among the composition, microstructure and strength of materials is always one of the hotspots for scholars of materials research. The influence of curing time on the compressive strength and flexural strength of the foam concrete with the cement, cement-slag and cement-steel slag as main binder respectively was studied in this paper. The microstructure of these foam concrete was analyzed by SEM and the mineral phases of the foam concrete was analyzed by XRD. The relationship among the binders, microstructure, mineral phases and strength of the foam concrete were explored and the reasons of why the strength of the cement foam concrete and cement-slag foam concrete is much higher than that of the cement-steel slag foam concrete are proposed.

scholarly journals Experimental Study on the Effect of Compound Activator on the Mechanical Properties of Steel Slag Cement Mortar

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 658
Author(s):  
Junfeng Guan ◽  
Yulong Zhang ◽  
Xianhua Yao ◽  
Lielie Li ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Silica Fume ◽  
Steel Slag ◽  
Cementitious Materials ◽  
Control Group ◽  
Optimal Dosage ◽  
Slag Powder ◽  
Mortar Strength ◽  
Steel Slag Powder

In this study, activator, metakaolin, and silica fume were used as a compound activator to improve the activity of steel slag powder. The influence of activator, steel slag powder, metakaolin, and silica fume on the resulting strength of steel slag cement mortar was investigated by orthogonal experiments. For four weight fractions of steel slag powder (10%, 20%, 30%, 40%), the experimental results indicate that the compressive strength of mortar can reach up to more than 85% of the control group while the flexural strength can reach up to more than 90% of the flexural strength of the control group. Through orthogonal analysis, it is determined that the activator is the primary factor influencing the mortar strength. According to the result of orthogonal analysis, the optimal dosages of activator, steel slag powder, metakaolin, and silica fume are suggested. The GM (0, N) prediction model of compressive strength and flexural strength was established, and the compressive strength and flexural strength of mortar with the optimal dosage combinations were predicted. The prediction results show that by using the optimal dosage combination, the mortar strength can reach the level of P·O·42.5 cement. Considering the different strength and cost requirements of cementitious materials in practical engineering, the economic benefits of replacing cement with steel slag powder activated by compound activator in various proportions and equal amounts were presented. The results show that the method proposed in this study can reduce the cost of cementitious materials.

An evaluation of ECT sample height for small flute board grades and Box Manufacturer’s Certification compliance

TAPPI Journal ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 24-28
Author(s):  
CORY JAY WILSON ◽  
BENJAMIN FRANK
Keyword(s):  
Compressive Strength ◽  
Compressive Load ◽  
Test Sample ◽  
Test Methods ◽  
Test Method ◽  
Initial Development ◽  
Sample Height ◽  
Relationship Of ◽  
The Relationship ◽  
Corrugated Fiberboard

TAPPI test T811 is the specified method to ascertain ECT relative to box manufacturer’s certification compliance of corrugated fiberboard under Rule 41/ Alternate Item 222. T811 test sample heights were derived from typical board constructions at the time of the test method’s initial development. New, smaller flute sizes have since been developed, and the use of lighter weight boards has become more common. The T811 test method includes sample specifications for typical A-flute, B-flute, and C-flute singlewall (and doublewall and triplewall) structures, but not for newer thinner E-flute or F-flute structures. This research explores the relationship of ECT sample height to measured compressive load, in an effort to determine valid E-flute and F-flute ECT sample heights for use with the T811 method. Through this process, it identifies challenges present in our use of current ECT test methods as a measure of intrinsic compressive strength for smaller flute structures. The data does not support the use of TAPPI T 811 for ECT measurement for E and F flute structures, and demonstrates inconsistencies with current height specifi-cations for some lightweight B flute.

scholarly journals The Effect of Different Types of Internal Curing Liquid on the Properties of Alkali-Activated Slag (AAS) Mortar

2021 ◽  
Vol 13 (4) ◽  
pp. 2407
Author(s):  
Guang-Zhu Zhang ◽  
Xiao-Yong Wang ◽  
Tae-Wan Kim ◽  
Jong-Yeon Lim ◽  
Yi Han
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Deionized Water ◽  
Internal Curing ◽  
Control Group ◽  
Alkali Activated Slag ◽  
Different Types ◽  
Naoh Solution ◽  
Activated Slag ◽  
Alkali Activated

This study shows the effect of different types of internal curing liquid on the properties of alkali-activated slag (AAS) mortar. NaOH solution and deionized water were used as the liquid internal curing agents and zeolite sand was the internal curing agent that replaced the standard sand at 15% and 30%, respectively. Experiments on the mechanical properties, hydration kinetics, autogenous shrinkage (AS), internal temperature, internal relative humidity, surface electrical resistivity, ultrasonic pulse velocity (UPV), and setting time were performed. The conclusions are as follows: (1) the setting times of AAS mortars with internal curing by water were longer than those of internal curing by NaOH solution. (2) NaOH solution more effectively reduces the AS of AAS mortars than water when used as an internal curing liquid. (3) The cumulative heat of the AAS mortar when using water for internal curing is substantially reduced compared to the control group. (4) For the AAS mortars with NaOH solution as an internal curing liquid, compared with the control specimen, the compressive strength results are increased. However, a decrease in compressive strength values occurs when water is used as an internal curing liquid in the AAS mortar. (5) The UPV decreases as the content of zeolite sand that replaces the standard sand increases. (6) When internal curing is carried out with water as the internal curing liquid, the surface resistivity values of the AAS mortar are higher than when the alkali solution is used as the internal curing liquid. To sum up, both NaOH and deionized water are effective as internal curing liquids, but the NaOH solution shows a better performance in terms of reducing shrinkage and improving mechanical properties than deionized water.

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