Analysis on Changes in Strength, Chloride Diffusion, and Passed Charges in Normal Concrete Considering Ages and Mix Proportions

Chloride ion penetration is an important parameter influencing the service life of a concrete structure, especially in aggressive environments. Severe chloride-induced corrosion of reinforced concretes has been reported in the southern part of Iran in the region of Oman Sea. In this paper, the effect of different environmental conditions of the Oman Sea on chloride penetration and mechanical properties of self-compacting concrete (SCC) and normal concrete (NC) is investigated. For this purpose, a number of prismatic specimens were exposed to various environmental conditions such as tide, submersion and atmospheric conditions. Surface chloride concentration and diffusion coefficient of SCC in these zones were calculated based on Fick’s second law, at 28, 90 and 150 days and compared with NC. Based on the values obtained in this study, relationships are proposed for concrete permeability and surface chloride of self-compacting concrete (SCC) at different ages in different aggressive environments. By determining the corrosion time based on these relations, it is observed that for a given water-to-cement ratio, the self-compacting concrete (SCC) has higher durability compared to normal concrete (NC).

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Comparison of chloride penetration into surface-treated concrete in artificial and natural environments

Advances in Structural Engineering ◽

10.1177/1369433216677123 ◽

2016 ◽

Vol 20 (9) ◽

pp. 1315-1324 ◽

Cited By ~ 1

Author(s):

Jianfeng Dong ◽

Yuxi Zhao ◽

Yueliang Gan ◽

Chaomei Ding ◽

Qiming He

Keyword(s):

Diffusion Coefficients ◽

High Performance ◽

High Performance Concrete ◽

Chloride Penetration ◽

Chloride Diffusion ◽

Natural Environments ◽

Nacl Solution ◽

Normal Concrete ◽

Wetting And Drying

This study investigated the penetration of chloride into surface-treated high-performance concrete and normal concrete in natural and accelerated environments. Both high-performance concrete and normal concrete were applied in a real port. Concrete specimens that were cast together with the concrete port were transported to the laboratory and subjected to wetting and drying cycles with NaCl solution. The chloride contents of the specimens in the laboratory and the in situ components were tested. The chloride diffusion coefficients and surface chloride contents were calculated based on Fick’s second law. The results show that high-performance concrete and surface treatment clearly slow the chloride penetration into the concrete both in the laboratory and in situ. The chloride contents on the surface and in the concrete in the components of the concrete port are higher during the summer than during the winter. The chloride penetration performance in the concrete of real structures cannot be inferred from its performance in specimens under artificial environments in the laboratory.

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Ultrahigh Performance Concrete: A Potential Material for Sustainable Marine Construction in View of the Service Life

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.438-439.108 ◽

2013 ◽

Vol 438-439 ◽

pp. 108-112 ◽

Cited By ~ 1

Author(s):

Chun Ping Gu ◽

Wei Sun ◽

Li Ping Guo ◽

Qian Nan Wang

Keyword(s):

Reinforced Concrete ◽

Service Life ◽

High Performance ◽

High Performance Concrete ◽

Chloride Diffusion ◽

Sustainable Construction ◽

Chloride Diffusion Coefficient ◽

Normal Concrete ◽

Superior Mechanical Properties ◽

Chloride Profiles

Ultrahigh performance concretes (UHPC) are promising materials for the next generation infrastructures due to their superior mechanical properties and durability. In this paper, comparison studies were conducted to show the potential of UHPC for sustainable constructions in chloride environments in view of service life. For reinforced concrete, the service life was calculated with analytical solution of Ficks second law on diffusion. And for reinforced concrete with nonlinear initial chloride profiles and depth-dependent chloride diffusion coefficient, a numerical method based on the Crank-Nicholson numerical scheme was adopted to predict the service life. The results show that the reinforced concrete structures constructed and repaired with UHPC have much longer service life than that of normal concrete (NC) and high performance concrete (HPC). It hence needs less cost for maintenance and reconstruction, which fulfills the requirements of sustainable construction.

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Variasi Penambahan Sika Cim Dan Fiber Kawat Pada Beton Mutu Fc’ 30 Mpa

Jurnal Intake : Jurnal Penelitian Ilmu Teknik dan Terapan ◽

10.32492/jintake.v9i2.776 ◽

2018 ◽

Vol 9 (2) ◽

pp. 67-73

Author(s):

M Zainul Arifin

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Curing Temperature ◽

Test Results ◽

Concrete Compressive Strength ◽

Normal Concrete ◽

Astm Method ◽

Additive Type ◽

Composition Variation ◽

Compressive Strength Of Concrete

This research was conducted to determine the value of the highest compressive strength from the ratio of normal concrete to normal concrete plus additive types of Sika Cim with a composition variation of 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1 , 50% and 1.75% of the weight of cement besides that in this study also aims to find the highest tensile strength from the ratio of normal concrete to normal concrete in the mixture of sika cim composition at the highest compressive strength above and after that added fiber wire with a size diameter of 1 mm in length 100 mm with a ratio of 1% of material weight. The concrete mix plan was calculated using the ASTM method, the matrial composition of the normal concrete mixture as follows, 314 kg / m3 cement, 789 kg / m3 sand, 1125 kg / m3 gravel and 189 liters / m3 of water at 10 cm slump, then normal concrete added variations of the composition of sika cim 0.25%, 0.50%, 0.75%, 1.00%, 1.25%, 1.5%, 1.75% by weight of cement and fiber, the tests carried out were compressive strength of concrete and tensile strength of concrete, normal maintenance is soaked in fresh water for 28 days at 30oC. From the test results it was found that the normal concrete compressive strength at the age of 28 days was fc1 30 Mpa, the variation in the addition of the sika cim additive type mineral was achieved in composition 0.75% of the cement weight of fc1 40.2 Mpa 30C. Besides that the tensile strength test results were 28 days old with the addition of 1% fiber wire mineral to the weight of the material at a curing temperature of 30oC of 7.5%.

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