Experimental Research on the Evaluation Method of the Resistance to Chloride Ion Penetration of Autoclaved PHC Pile

The usage of autoclaved PHC pile in chloride environment becomes common, so how to evaluate the resistance to chloride ion penetration of autoclaved PHC pile becomes urgent. This article Compare the resistance to chloride ion penetration of pile and pile concrete specimens based the Rapid Chloride Migration Synthesis Method and RCM. The results show that the Rapid Chloride Migration Synthesis Method is not suitable for pile, RCPT and RCM are suitable for pile; the resistance to chloride ion penetration of the pile inner and outer lateral concrete has a rather large different, so the sample must distinguish the direction when testing. Steel bar has little influence on the resistance to chloride ion penetration of autoclaved PHC pile, and the resistance to chloride ion penetration of pile outer lateral concrete is similar with pile concrete specimen, using pile concrete specimen to test the resistance to chloride ion penetration of autoclaved PHC pile is suitable. The chloride diffusion coefficient values have a good relationship with the electricity value, using the electricity value of square pile concrete specimen as commonly quality control way are suggested. The resistance to chloride ion penetration of pile can test the outer lateral concrete of pile or pile head, using the electricity value as daily quality control method and basis for project acceptance, and using RCM method as life assessment and basis for project acceptance.

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The Chloride Ion Penetration Model Coupled with Temperature and Moisture Transfer in Marine Environment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.591-593.2422 ◽

2012 ◽

Vol 591-593 ◽

pp. 2422-2427

Author(s):

Juan Zhao

Keyword(s):

Marine Environment ◽

Moisture Transfer ◽

Regional Climate ◽

Chloride Ion ◽

Chloride Penetration ◽

Chloride Diffusion ◽

Tidal Zone ◽

Analog Simulation ◽

Chloride Ion Penetration ◽

Ion Penetration

Considering the complexity of the chloride ion penetration in concrete exposed to marine environment, an integrated chloride penetration model coupled with temperature and moisture transfer is proposed. The governing equations and parameters embody fully the cross-impacts among thermal conduction, moisture transfer and chloride ion penetration. Furthermore, the four exposure conditions are classified based on the different contact with the aggressive marine environment, and then the micro-climate condition on the concrete surface is investigated according to the regional climate characteristics, therefore, a comprehensive analog simulation to the chloride penetration process is proposed. To demonstrate that the proposed numerical model can correctly simulate the chloride diffusion in concrete, the integrated chloride diffusion model is applied in reproducing a real experiment, finally the model gives good agreement with the experimental profiles, and it is proved the tidal zone exposure results in a more severe attack on the reinforcement

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The Influence of the Hybridization of Steel and Polyolefin Fiber on the Mechanical Properties of Base Concrete Designed for Marine Shotcreting Purposes

Applied Sciences ◽

10.3390/app11209456 ◽

2021 ◽

Vol 11 (20) ◽

pp. 9456

Author(s):

Changjoon Lee ◽

Andres Salas Montoya ◽

Hoon Moon ◽

Hyunwook Kim ◽

Chulwoo Chung

Keyword(s):

Steel Fiber ◽

Mechanical Performance ◽

Synergetic Effect ◽

Chloride Ion ◽

Concrete Specimen ◽

Hybrid Fiber ◽

Electrically Conductive ◽

Chloride Ion Penetration ◽

Binder Ratio ◽

Ion Penetration

The present study investigated the influence of the hybridization of steel and polyolefin fiber on the mechanical performance and chloride ion penetration of base concrete designed for marine shotcreting purposes. The purpose of fiber hybridization is to reduce the risk of corrosion that might occur during service life. Sets of hybrid fiber reinforced base concrete, whose water to binder ratio was 0.338, were prepared. The fiber contents in the base concrete were 0.54 and 1.08 vol%, and the volume proportion of polyolefin fiber in the hybrid fiber varied from 0 to 100%. Although the effect of fiber hybridization was not clearly observed from the compressive strength, a synergetic effect which increased both the flexural strength and toughness occurred at a fiber content of 1.08 vol%. The optimum ratio of steel and polyolefin fiber was 50:50. With respect to chloride ion penetration, an increasing amount of steel fiber increased the amount of current passing through the base concrete specimen due to the presence of electrically conductive steel fiber. However, chloride ion diffusivity was not greatly affected by the presence of steel fiber.

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The Influence of Crystalline Admixtures on the Properties and Microstructure of Mortar Containing By-Products

Buildings ◽

10.3390/buildings10090146 ◽

2020 ◽

Vol 10 (9) ◽

pp. 146

Author(s):

Jakub Hodul ◽

Nikol Žižková ◽

Ruben Paul Borg

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Chloride Ion ◽

Capillary Suction ◽

Chloride Ion Penetration ◽

Chloride Migration ◽

Cement Mortars ◽

Polymer Mortar ◽

By Products ◽

Ion Penetration

Crystalline admixtures and industrial by-products can be used in cement-based materials in order to improve their mechanical properties. The research examined long-term curing and the exposure to environmental actions of polymer–cement mortars with crystalline admixture (CA) and different by-products, including Bengħisa fly ash and Globigerina limestone waste filler. The by-products were introduced as a percentage replacement of the cement. A crystallization additive was also added to the mixtures in order to monitor the improvement in durability properties. The mechanical properties of the mortar were assessed, with 20% replacement of cement with fly ash resulting in the highest compressive strength after 540 days. The performance was analyzed with respect to various properties including permeable porosity, capillary suction, rapid chloride ion penetration and chloride migration coefficient. It was noted that the addition of fly ash and crystalline admixture significantly reduced the chloride ion penetration into the structure of the polymer cement mortar, resulting in improved durability. A microstructure investigation was conducted on the samples through Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDS). Crystals forming through the crystalline admixture in the porous structure of the material were clearly observed, contributing to the improved properties of the cement-based polymer mortar.

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Transport of Water and Chloride Ion in Cement Composites Modified with Graphene Nanoplatelet

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.629-630.162 ◽

2014 ◽

Vol 629-630 ◽

pp. 162-167 ◽

Cited By ~ 2

Author(s):

Hong Jian Du ◽

Sze Dai Pang

Keyword(s):

Chloride Ion ◽

Chloride Ions ◽

Chloride Diffusion ◽

Cement Composites ◽

Chloride Diffusion Coefficient ◽

Barrier Effect ◽

Graphene Nanoplatelet ◽

Chloride Migration ◽

Corrosion Of Steel ◽

And Diffusion

Cement composites are vulnerable to harsh environments in which the chloride ions can ingress into concrete and thus cause corrosion of steel. In this study, the barrier effect of adding 2-D nanoparticles on the transport properties of cement-based materials was investigated. Graphene nanoplatelet (GNP), which comprises of a few layers of graphene stacked together, is chosen as a candidate in this study due to its impermeability and also its electrical conductivity which can be exploited for self-sensing functionality. Due to the large aspect ratio of the GNP, it is expected that the dispersion of these 2-D nanobarriers can contribute to the reduced permeability and diffusion of harmful agents. Experiments were carried out on cement mortar with 0%, 2.5%, 5.0% and 7.5% of GNP by weight of cement. The water penetration depth, chloride diffusion coefficient and chloride migration coefficient were reduced by 64%, 70% and 31% respectively with the addition of as little as 2.5% of GNP. This reduction can be attributed to the barrier effect of GNP which increases the tortuosity against water and chloride ions penetration, and also the refinement of the capillary pores which was revealed from the MIP tests. At GNP content exceeding 5%, the nanoparticles agglomerate, causing weak pockets which compromises the benefits of adding GNP to impede the ingress of fluids.

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A STUDY ON IMPROVEMENT AND ITS EVALUATION FOR THE SURFACE LAYER OF CONCRETE PLACED WITH PERMEABLE FORM

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194512003947 ◽

2012 ◽

Vol 06 ◽

pp. 664-669

Author(s):

RYOICHI TANAKA ◽

TAKASHI HABUCHI ◽

TAKAHIKO AMINO ◽

TSUTOMU FUKUTE

Keyword(s):

Surface Layer ◽

Chloride Ion ◽

Concrete Specimen ◽

Air Permeability ◽

Permeability Test ◽

Carbonation Depth ◽

Chloride Ion Penetration ◽

Rebound Number ◽

Ion Penetration

Permeable form can improve the quality of the surface layer of concrete and can enhance the durability of concrete structures. In this study, the improvement and its evaluation for the surface layer of concrete placed with permeable form were investigated. For these purposes, accelerated carbonation test, chloride ion penetration test, air permeability test, rebound hummer test and water permeability test were conducted using the concrete specimen. As a result, it was found that the air permeability correlates the carbonation depth, chloride ion penetration depth, rebound number and water permeable volume of concrete. Moreover, the possibility that the improvement for the surface layer of concrete can be quantitatively evaluated by air permeability test was shown.

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Penetration Behavior of Chloride Ions into Concrete in Coastal Areas

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.302-303.584 ◽

2006 ◽

Vol 302-303 ◽

pp. 584-590

Author(s):

Yoshihiro Masuda ◽

F.-R. Wu ◽

S. Nakamura ◽

S. Sato

Keyword(s):

Chloride Ion ◽

Concrete Specimen ◽

Chloride Ions ◽

Ion Content ◽

Exposure Test ◽

Total Chloride ◽

Chloride Ion Penetration ◽

Apparent Diffusion ◽

Penetration Behavior ◽

Ion Penetration

Exposure test on chloride ion penetration behavior into Concrete in coastal area was implemented. The distances between concrete specimens and coast were changed in the range from 50 to 150 meters, and water-cement ratios (W/C) were 45, 55, 60 and 65 %. The total chloride ion content at each different depth from surface of concrete specimen was measured at the age of 1, 2, 3, 5, 7, 8 and 10 years. In this paper, apparent diffusion coefficient (D) and chloride ion content on surface of concrete (C0) were calculated by inverse analyses from the measured total chloride ion content, and the chloride ion penetration behavior was simulated using the calculated D and C0. As a result, the chloride ion penetrated in concrete with a W/C of 60 % at a point 50 m from the sea for 10 years was estimated approximately 0.2 kg/m3.

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Study on Chloride Ion Penetration for Concrete Structures in Zhunhai Area

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.405-408.2703 ◽

2013 ◽

Vol 405-408 ◽

pp. 2703-2706

Author(s):

Yi Wan ◽

Zhi Wu Yu ◽

Peng Liu

Keyword(s):

Chloride Concentration ◽

Chloride Ion ◽

Local Environment ◽

Ion Concentration ◽

Chloride Diffusion ◽

Chloride Diffusion Coefficient ◽

The Road ◽

Free Chloride ◽

Chloride Ion Penetration ◽

On The Road

The chloride concentration distribution is an efficient method of evaluating corrosion characteristics of concrete structures.A number of concrete samples at various positions were drilled in Zhuhai area and the free chloride concentration of concrete were determinated.Besides,the influences of elevations,distances from the sea and the local environment on chloride were analyzed.The value of chloride diffusion coefficient and surface chloride ion concentration along various elevation at the sea were calculated according to Fick's second law.The results show that chloride's erosion aciton tends to reduction with elevation and it is the most serious at an elevation of 1 meter for concrete by the sea.There is the large convective depth in alternate wetting-dry ares.Whereas it is just about 0.02%-0.05% on the road,at the distance of 15 kilometers from the seafront,which indicates that the father away from the seafront,the weaker chloride's erosion action becomes.

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The Durability Failure of Pre-Damaged Concrete Induced by Mechanical Load

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.594-597.1061 ◽

2012 ◽

Vol 594-597 ◽

pp. 1061-1065

Author(s):

Fang Zhi Zhu ◽

Fu Xiang Jiang ◽

Jun Shang ◽

Zhong Hua Bi

Keyword(s):

Chloride Ion ◽

Load Level ◽

Uniaxial Tensile ◽

Chloride Diffusion Coefficient ◽

Freezing And Thawing ◽

Chloride Ion Penetration ◽

Negative Effect ◽

The Impact ◽

Durability Of Concrete ◽

Ion Penetration

Chloride ion penetration and freezing and thawing damage are the two main factors that affect the durability of concrete structures. Through the chloride ion penetration test and freezing and thawing test of concrete specimens after tensile and compressive loading, the influence of load-induced damage on the long-term durability of concrete was studied. The results showed that the apparent chloride diffusion coefficient of concrete increased by 6.4% and 34%, and the surface chloride concentration increased 10% and 40%, respectively, both of which showed the "negative effect" when the uniaxial tensile load level reached the 65% and 75% of the ultimate capacity. However, with the increasing uniaxial compressive load level, the impact on the frost resistance of concrete experienced a transformation from the "positive effect" to the "negative effect".

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