scholarly journals Effect of Carbonation Curing on Physical and Durability Properties of Cementitious Materials Containing AOD Slag

2020 ◽  
Vol 10 (19) ◽  
pp. 6646
Author(s):  
Byoungsun Park ◽  
Young Cheol Choi
Keyword(s):  
Diffusion Coefficient ◽  
Drying Shrinkage ◽  
Co2 Concentration ◽  
Cementitious Materials ◽  
Chloride Diffusion ◽  
Co2 Uptake ◽  
Chloride Diffusion Coefficient ◽  
Durability Properties ◽  
Carbonation Curing ◽  
Aod Slag

In this study, the physical and durability properties of cementitious materials containing stainless steel argon-oxygen decarburization (AOD) slag were investigated by CO2 curing. Three contents (0, 30, 60%) of ordinary Portland cement (OPC) were replaced with AOD slag. Specimens were cured at four CO2 concentrations and three temperatures. The chloride diffusion coefficient, drying shrinkage, compressive strength, and porosity were measured. The drying shrinkage reduction was proportional to CO2 uptake. The chloride diffusion coefficient increased as contents of the AOD slag increased. At 15% CO2 concentration, the diffusion coefficient was similar to that of the OPC regardless of the AOD slag substitution rate. The durability of cementitious materials mixed with AOD slag can be improved by CO2 curing and can be used in construction.

scholarly journals Effects after 1500 Hardening Days on the Microstructure and Durability-Related Parameters of Mortars Produced by the Incorporation of Waste Glass Powder as a Clinker Replacement

2021 ◽  
Vol 13 (7) ◽  
pp. 3979
Author(s):  
Rosa María Tremiño ◽  
Teresa Real-Herraiz ◽  
Viviana Letelier ◽  
Fernando G. Branco ◽  
José Marcos Ortega
Keyword(s):  
Diffusion Coefficient ◽  
Water Absorption ◽  
Glass Powder ◽  
Cementitious Materials ◽  
Cement Industry ◽  
Waste Glass ◽  
Supplementary Cementitious Materials ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Waste Glass Powder

One of the ways of lessening the CO2 emissions of cement industry consists of replacing clinkers with supplementary cementitious materials. The required service life of real construction elements is long, so it is useful to characterize the performance of these materials in the very long term. Here, the influence of incorporating waste glass powder as a supplementary cementitious material, regarding the microstructure and durability of mortars after 1500 hardening days (approximately 4 years), compared with reference mortars without additions, was studied. The percentages of clinker replacement by glass powder were 10% and 20%. The microstructure was studied using impedance spectroscopy and mercury intrusion porosimetry. Differential thermal and X-ray diffraction analyses were performed for assessing the pozzolanic activity of glass powder at the end of the time period studied. Water absorption after immersion, the steady-state diffusion coefficient, and length change were also determined. In view of the results obtained, the microstructure of mortars that incorporated waste glass powder was more refined compared with the reference specimens. The global solid fraction and pores volume were very similar for all of the studied series. The addition of waste glass powder reduced the chloride diffusion coefficient of the mortars, without worsening their behaviour regarding water absorption after immersion.

Influence of Mineral Admixtures on Chloride Diffusion Coefficient of Self-Compacting Concrete

2013 ◽  
Vol 405-408 ◽  
pp. 2876-2880
Author(s):  
Jian Bo Xiong ◽  
Peng Ping Li ◽  
Sheng Nian Wang
Keyword(s):  
Diffusion Coefficient ◽  
Fly Ash ◽  
Cementitious Materials ◽  
Ash Content ◽  
Mineral Admixtures ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Self Compacting Concrete ◽  
Granulated Blast Furnace Slag ◽  
Furnace Slag

The influence of mineral admixtures on workability of fresh concrete and chloride ion permeability resistance of hardened concrete for C50 self-compacting concrete was investigated by means of the Natural Immersion Test. The results showed that the chloride diffusion coefficient in fly ash concrete decreased first and then increased with increasing fly ash content in cementitious materials, when fly ash content was 30% or 40%, it got the lowest value at 28 days or 90 days, respectively. The chloride diffusion coefficient in specimens decreased with increasing the ground granulated blast furnace slag content in cementitious materials, but it changed little when the replacement was in ranges of 50% to 60%. Furthermore, for the specimens which replaced by fly ash and ground granulated blast furnace slag, the chloride diffusion coefficient decreased first and then increased with increasing the fly ash content in complex cementitious, and when fly ash content was 10% or 20%, it got the lowest value at 28 days or 90 days, respectively.

Theoretical Analysis of Chloride Ion Migration Tests in Cementitious Material Research

2012 ◽  
Vol 450-451 ◽  
pp. 21-25
Author(s):  
Jin Bo Yang ◽  
Reng Guang Liu
Keyword(s):  
Diffusion Coefficient ◽  
Theoretical Calculations ◽  
Chloride Ion ◽  
Cementitious Materials ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Accelerated Tests ◽  
Penetration Test ◽  
Migration Test ◽  
Ion Migration

Chloride ion migration tests, or so called electrical accelerated tests, for testing chloride diffusion coefficient of cementitious materials are reviewed. The ion migration theory of electrical accelerated tests is presented. Four main representative measures, chloride penetration test, steady state migration test, unsteady state migration test and salt saturated conductivity test, are introduced and their theoretical calculations of chloride diffusion coefficient are described. Through analysis of the theoretical calculations, it could be found that all electrical accelerated tests are based on ion migration theory although different suppositions are adopted. Steady state migration test is the most suitable measure to determine chloride diffusion coefficient among the migration tests. DCIPT, DRCM and DSSCT calculated by chloride penetration test, unsteady state migration test and salt saturated conductivity test could be used to identify the resistance to chloride ion penetration of cementitious materials but are not the real diffusion coefficient.

scholarly journals Effects of Nanosilica on Compressive Strength and Durability Properties of Concrete with Different Water to Binder Ratios

2016 ◽  
Vol 2016 ◽  
pp. 1-16 ◽  
Author(s):  
Forood Torabian Isfahani ◽  
Elena Redaelli ◽  
Federica Lollini ◽  
Weiwen Li ◽  
Luca Bertolini
Keyword(s):  
Compressive Strength ◽  
Diffusion Coefficient ◽  
Reference Value ◽  
Chloride Diffusion ◽  
Gravimetric Analysis ◽  
Chloride Diffusion Coefficient ◽  
X Ray Diffraction ◽  
Durability Properties ◽  
Water Sorptivity ◽  
Strength And Durability

The effects of the addition of different nanosilica dosages (0.5%, 1%, and 1.5% with respect to cement) on compressive strength and durability properties of concrete with water/binder ratios 0.65, 0.55, and 0.5 were investigated. Water sorptivity, apparent chloride diffusion coefficient, electrical resistivity, and carbonation coefficient of concrete were measured. The results showed that compressive strength significantly improved in case of water/binder = 0.65, while for water/binder = 0.5 no change was found. Increasing nanosilica content, the water sorptivity decreased only for water/binder = 0.55. The addition of 0.5% nanosilica decreased the apparent chloride diffusion coefficient for water/binder = 0.65 and 0.55; however, higher nanosilica dosages did not decrease it with respect to reference value. The resistivity was elevated by 0.5% nanosilica for all water/binder ratios and by 1.5% nanosilica only for water/binder = 0.5. The carbonation coefficient was not notably affected by increasing nanosilica dosages and even adverse effect was observed for water/binder = 0.65. Further information of microstructure was also provided through characterization techniques such as X-ray diffraction, thermal gravimetric analysis, mercury intrusion porosimetry, and scanning electron microscopy. The effectiveness of a certain nanosilica dosage addition into lower strength mixes was more noticeable, while, for the higher strength mix, the effectiveness was less.

scholarly journals Experimental Study on Effective Chloride Diffusion Coefficient of Cement Mortar by Different Electrical Accelerated Measurements

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 240
Author(s):  
Jianlan Chen ◽  
Jiandong Wang ◽  
Rui He ◽  
Huaizhu Shu ◽  
Chuanqing Fu
Keyword(s):  
Diffusion Coefficient ◽  
Cement Mortar ◽  
Early Stage ◽  
Chloride Concentration ◽  
Chloride Diffusion ◽  
Chloride Diffusion Coefficient ◽  
Cement Ratio ◽  
Water To Cement Ratio ◽  
Good Consistency ◽  
Determination Methods

This study investigated the effective chloride diffusion coefficient of cement mortar with different water-to-cement ratio (w/c) under electrical accelerated migration measurement. The cumulative chloride concentration in anode cell solution and the cumulative chloride concentration drop in the cathode cell solution was measured by RCT measurement and the results were further used to calculate the chloride diffusion coefficient by Nordtest Build 355 method and Truc method. The influence of w/c on cement mortar’s chloride coefficient was investigated and the chloride diffusion coefficient under different determination methods were compared with other researchers’ work, a good consistency between this work’s results and literatures’ results was obtained. The results indicated that the increased w/c of cement mortar samples will have a higher chloride diffusion coefficient. The cumulative chloride concentration drop in the cathode cell solution will have deviation in early stage measurement (before 60 h) which will result in overestimation of the effective chloride diffusion coefficient.

scholarly journals Influence of Hydrostatic Pressure and Cationic Type on the Diffusion Behavior of Chloride in Concrete

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2851
Author(s):  
Huanqiang Liu ◽  
Linhua Jiang
Keyword(s):  
Diffusion Coefficient ◽  
Hydrostatic Pressure ◽  
Diffusion Model ◽  
Coupling Effect ◽  
Experimental Results ◽  
Chloride Diffusion ◽  
Concrete Durability ◽  
Chloride Diffusion Coefficient ◽  
Diffusion Behavior ◽  
Diffusion Source

The durability of the concrete in underground and marine engineering is affected by the underground and ocean environment. Chloride diffusion coefficient under hydrostatic pressure is a key parameter of concrete durability design under corresponding conditions. Therefore, this paper studies the diffusion behavior of chloride in different diffusion source solutions by experiment and simulation. Based on the experimental results, this paper proposes a new chloride diffusion model under the coupling effect of diffusion and convection. The interaction of ions and compounds in the diffusion source solutions, concrete pore fluid, and concrete material are considered in the new chloride diffusion model. The experimental results show that chloride diffusion rate is significantly affected by hydrostatic pressure, which increases with the increase of hydrostatic pressure. The chloride diffusion coefficient shows a certain difference in difference diffusion source solutions. The chloride diffusion coefficient in divalent cationic diffusion source solutions is the largest, the chloride diffusion coefficient in the divalent and monovalent cationic compound ones is in the middle, and the chloride diffusion coefficient in the monovalent cationic ones is the smallest. There is a linear relationship between the chloride diffusion coefficient and the hydrostatic pressure whether in single or combined cationic diffusion source solutions.

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