Analysis of calcium leaching behavior of plain and modified cement pastes in pure water

Calcium leaching degradation could be happened in reinforcement concrete member due to the contact with pure water in underground condition. Thus, it is needed to evaluate the resistance of calcium leaching for concrete mixed with mineral admixtures. So, in this paper, to evaluate the flexural behavior in RC member with mineral admixture under calcium leaching degradation, we investigated the effect of calcium leaching using the non-linear finite-element program. From the results, the load capacity and flexible rigidity of a degraded RC member decrease when the degradation level increases with leaching period. And, regardless of the type of mineral admixtures, finite-element-method analysis effectively showed the characteristics of calcium leaching damaged RC beam.

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Rheology of pure and mineral admixture modified cement pastes and their degradation due to calcium leaching

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/490/3/032031 ◽

2019 ◽

Vol 490 ◽

pp. 032031

Author(s):

Hu Yang ◽

Cairong Lu ◽

Weibao Liu ◽

Guoxing Mei ◽

Heng Wang ◽

...

Keyword(s):

Mineral Admixture ◽

Cement Pastes ◽

Calcium Leaching

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Prediction of the Deterioration Depth of Concrete by Accelerating Calcium Leaching Test

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.365.3 ◽

2011 ◽

Vol 365 ◽

pp. 3-7 ◽

Cited By ~ 1

Author(s):

An Cheng ◽

Sao Jeng Chao ◽

Wei Ting Lin ◽

Jia Liang Chang

Keyword(s):

Nitrate Solution ◽

Leaching Behavior ◽

Calcium Leaching ◽

Ammonium Nitrate Solution ◽

Binder Ratio ◽

Two Stages ◽

Strength And Durability ◽

Calcium Ion Leaching ◽

Water Binder Ratio

The concrete is a solid and porous composite materials, when the concrete exposure to moisture environment for a long-term, the pore water will penetrate into concrete cause hydration products leaching. Leaching of calcium ions increase in porosity and resulting in harmful ions ingress into concrete to reduce strength and durability of concrete. The purpose of this study is to evaluate the effect of water-binder ratio on calcium ion leaching behavior of cement-based material. The ammonium nitrate solution was used to accelerate leaching process. Leaching duration was 56 days, 91 days and 140 days, respectively. The leaching depth and compressive strength were measured. The results showed that leaching resistance increased with a decrease in water/binder ratio. The leaching depth showed that leaching behavior of the specimens without minerals admixtures can be divided into two stages, the first stage was leaching of calcium hydroxide and than the C-S-H gel were leaching.

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The Effect of Various Lead Species on the Leaching Behavior of Borosilicate Waste Glass

MRS Proceedings ◽

10.1557/proc-44-179 ◽

1984 ◽

Vol 44 ◽

Cited By ~ 1

Author(s):

Richard L. lehman ◽

Frank A. Kuchinski

Keyword(s):

Weight Loss ◽

Glass Surface ◽

Lead Concentration ◽

Pure Water ◽

Waste Glass ◽

Leaching Behavior ◽

Weight Loss Data ◽

Nuclear Waste Glass ◽

Lead Metal ◽

Lead Species

AbstractA borosilicate nuclear waste glass was static leached in pure water, silicate water, and brine solution. Three different forms of lead were included in specified corrosion cells to assess the extent to which various lead species alter the leaching behavior of the glass. Weight loss data indicated that Pbm and Pb0 greatly reduce the weight loss of glass when leached in pure water, and similar effects were noted in silicate and brine. Si concentrations, which were substantial in the glass-alone leachate, were reduced to below detection limits in all pure water cells containing a lead form. Lead concentration levels in the leachate were controlled by lead form solubility and appeared to be a significant factor in influencing apparent leaching behavior. Surface analysis revealed surface crystals, which probably formed when soluble lead in the leachate reacted with dissolved or activated silica at the glass surface. The net effect was to reduce the release of some glass constituents to the leachate, although it was not clear whether the actual corrosion of the glass surface was reduced. Significantly different corrosion inhibiting effects were noted among lead metal and two forms of lead oxide.

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Impact of calcium leaching on chloride diffusion behavior of cement pastes exposed to ammonium chloride aqueous solution

Construction and Building Materials ◽

10.1016/j.conbuildmat.2017.07.094 ◽

2017 ◽

Vol 153 ◽

pp. 211-215 ◽

Cited By ~ 6

Author(s):

Zijian Song ◽

Linhua Jiang ◽

Hongqiang Chu

Keyword(s):

Aqueous Solution ◽

Ammonium Chloride ◽

Chloride Diffusion ◽

Cement Pastes ◽

Diffusion Behavior ◽

Calcium Leaching

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Fabrication and Characterization of Chelate-Setting β-Tricalcium Phosphate Cements with Enhanced Bioresorbability

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.720.157 ◽

2016 ◽

Vol 720 ◽

pp. 157-161

Author(s):

Kohei Nagata ◽

Toshiisa Konishi ◽

Michiyo Honda ◽

Mamoru Aizawa

Keyword(s):

Dissolution Rate ◽

Ball Milling ◽

Tricalcium Phosphate ◽

Inositol Phosphate ◽

Pure Water ◽

High Specific Surface Area ◽

Cement Pastes ◽

Sodium Hydrogen Phosphate ◽

Japanese Industrial Standard ◽

Human Cancellous Bone

A novel chelate-setting β-tricalcium phosphate (β-TCP) cement with anti-washout properties have been fabricated previously. This cement has been set on the basis of chelating ability of inositol phosphate (IP6). In this study, the ball-milling and surface-modification conditions of starting β-TCP cement powders were optimized in terms of bioresorbability. Starting powders were prepared by simultaneously ball-milling at 300 rpm for 3 h with 1 mm diameter ZrO2 beads and surface-modifying with 40 cm3 of 3000 ppm IP6 solution. The resulting starting powder was consisted of β-TCP single phase, and had high specific surface area of 48.3 m2∙g-1. Cement pastes were prepared by mixing the starting powder and the aqueous solution composed of 2.5 mass% sodium hydrogen phosphate, 1.5 mass% citric acid and 1.0 mass% sodium alginate at a powder/liquid ratio of 1/0.90 [g∙cm-3] for 2 min. After setting in pure water for 72 h, compressive strength of the cement specimens was higher than that of human cancellous bone. Dissolution rate of Ca2+ ions was measured by according to Japanese Industrial Standard T 0330-3. The results of Ca2+ ions dissolution rate test demonstrated that the cement specimens derived from the above starting powder were the highest dissolution rate among examined ones. This cement would be expected as bone fillers with high bioresobability.

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