Effect of rust inhibitors and surface strengthening materials on service life of marine RC structures

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Haiwei Zhu ◽  
Hongfa Yu ◽  
Haiyan Ma ◽  
Bo Da ◽  
Qiquan Mei
Keyword(s):  
Service Life ◽  
Chloride Ion ◽  
Life Extension ◽  
Marine Environments ◽  
Ion Diffusion ◽  
Content Type ◽  
Rc Structures ◽  
Surface Strengthening ◽  
Service Life Extension ◽  
Chloride Ion Diffusion

Purpose The purpose of this paper is to compare the effect of rust inhibitors and surface strengthening materials on the service life of RC structures in tropical marine environments and ultimately to provide basis and recommendations for the durability design of reinforced concrete (RC) structures. Design/methodology/approach Slag concrete specimens mixed with four kinds of rust inhibitors and coated with four kinds of surface strengthening materials were corroded by seawater exposure for 365 days, and the key parameters of chloride ion diffusion were obtained by testing. Then a new service life prediction model, based on the modified model for chloride ion diffusion and reliability theory, was applied to analyze the effect of rust inhibitors and surface strengthening materials on the service life of RC structures in tropical marine environments. Findings Rust inhibitors and surface strengthening materials can effectively extend the service life of RC structures through different effects on chloride ion diffusion behavior. The effects of rust inhibitors and surface strengthening materials on the service life extension of RC structures adhered to the following trend: silane material > cement-based permeable crystalline waterproof material > hydrophobic plug compound > spray polyurea elastomer > water-based permeable crystalline waterproof material > calcium nitrite > preservative > amino-alcohol composite. Originality/value Using a new method for predicting the service life of RC structures, the attenuation law of the service life of RC structures under the action of rust inhibitors and surface strengthening materials in tropical marine environments is obtained.

Study on the Durability of Concrete Structure of Aviation Oil Wharf of Shenzhen Airport

2010 ◽  
Vol 163-167 ◽  
pp. 1019-1023
Author(s):  
Wei Lun Wang ◽  
Ji Hua Zhu ◽  
Feng Xing
Keyword(s):  
Service Life ◽  
Concrete Structure ◽  
Chloride Ion ◽  
Ion Concentration ◽  
Ion Diffusion ◽  
Cell Potential ◽  
Shenzhen City ◽  
High Possibility ◽  
Chloride Ion Diffusion ◽  
Existing Structure

Due to the invasion of chloride ion, the reinforcement in coastal concrete structure is corroded, which causes damage to the concrete structure and becomes the major factor affecting the structure’s service life. Aiming at the existing concrete structure under the coastal environment of Shenzhen City, the durability experimental study has been implemented, discussing the main reason for the insufficient durability of the existing structure. The experiment result shows that the higher chloride ion diffusion coefficient (76.1×10-12 m2/s) in the concrete structure leads that the chloride ion concentration of the structure in the depth of 30mm surpasses one percent upon using it for two decades. The half-cell potential value also reflects the relatively high possibility of the reinforcement corrosion of the structure. Combining with the experiment result, the service life of this concrete structure has been analyzed, which is hard to be guaranteed to use for five decades under the current concrete parameters and resistance.

A Study on the Evaluation of Probabilistic Durability Life for RC Structures Deteriorated by Chloride Ion

2007 ◽  
Vol 348-349 ◽  
pp. 417-420
Author(s):  
Dong Seok Kim ◽  
Han Seung Lee ◽  
Seong Min Lee ◽  
Xiao Yong Wang
Keyword(s):  
Diffusion Coefficient ◽  
Concrete Structures ◽  
Prediction Method ◽  
Chloride Ion ◽  
Ion Diffusion ◽  
Rc Structures ◽  
Equivalent Age ◽  
Chloride Ion Penetration ◽  
Reliability Assessments ◽  
Chloride Ion Diffusion

Chloride attacks concrete structures becoming a primary factor that deteriorates the durability of concrete structures. For this reason, research has been conducted on chloride ion penetration and diffusion. This research produced an accurate durability life prediction through reliability assessments and proposes a prediction method for the chloride ion diffusion coefficient of a concrete applied assessment program for reliability. As a result, test materials were fabricated using different admixtures and chloride ion diffusion coefficient was calculated by applying an RCPT test at each equivalent age. Based on these results, reliability prediction formulas were indicated through the reliability analysis for a durability life design using a Montecarlo method. In addition, propriety was verified through comparisons and analysis using the proposed formula with the investigated data for chloride ion diffusion.

scholarly journals Variation in Service Life on RC Structure According to Concrete Binder Type

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5430
Author(s):  
JangHyun Park ◽  
JinHo Park ◽  
MyeongGyu Jung
Keyword(s):  
Service Life ◽  
Chloride Ion ◽  
Chloride Content ◽  
Reinforcing Bars ◽  
Ion Diffusion ◽  
Rc Structure ◽  
Binder Type ◽  
Chlorine Ions ◽  
Ph Level ◽  
Chloride Ion Diffusion

When an additive is used to replace a certain amount of cement, a concrete pore structure becomes dense. Thus, it results in inhibiting the penetration of chlorine ions and suppressing corrosion of reinforcing bars. However, the pH level of the concrete decreases, and it deteriorates the performance of the passive film formed on the surface of the rebars embedded in the concrete. Therefore, in this study, the service lives of reinforced concrete containing different types of concrete binders were predicted and compared. The chloride ion diffusion coefficients of concretes with various binders were measured, and the critical chloride content of the rebar was assessed by the real-time monitoring on the corrosion initiation time of the rebar embedded in concrete. Moreover, Fick’s 2nd law was applied to predict when the chloride content at the 40 mm depth of cover reached the critical chloride content based on the chloride ion diffusion coefficient. It was observed that the service life of S6 (OPC 40% + GGBFS 60%) was the highest, followed by TBC (OPC 40% + GGBFS 40% + FA 20%), S3 (OPC 70% + GGBFS 30%), and OPC (OPC 100%).

scholarly journals Effectiveness of the Novel Rehabilitation Method of Seismically Damaged RC Joints Using C-FRP Ropes and Comparison with Widely Applied Method Using C-FRP Sheets—Experimental Investigation

2021 ◽  
Vol 13 (11) ◽  
pp. 6454
Author(s):  
Emmanouil Golias ◽  
Adamantis G. Zapris ◽  
Violetta K. Kytinou ◽  
George I. Kalogeropoulos ◽  
Constantin E. Chalioris ◽  
...  
Keyword(s):  
Service Life ◽  
Active Regions ◽  
Life Extension ◽  
Rc Beam ◽  
Seismic Capacity ◽  
Rc Structures ◽  
Existing Structures ◽  
Service Life Extension ◽  
Column Joint

The necessity of ensuring the long-term sustainability of existing structures is rising. An important issue concerning existing reinforced concrete (RC) structures in seismically active regions is that a significant number of them lack the required earthquake-resistant capacities to meet the increased design earthquake demands. Inexpensive, fast and long-term strengthening strategies for repairing/strengthening RC structures are urgently required, not only after destructive earthquakes, but even before they occur. Retrofitting existing buildings extending their service life rather than demolishing and rebuilding new ones is the best option in terms of economic gain and environmental protection. This paper experimentally investigates the effectiveness of externally applied (i) carbon fiber-reinforced polymer (C-FRP) ropes in X-type form and (b) C-FRP sheets that are bonded on both sides of the joint area of RC beam-column joint connections. Six comparative full-scale exterior RC beam-column joint specimens were tested under reverse cyclic deformation. Two of them were control specimens, two were strengthened using C-FRP ropes (novel technique) and two were retrofitted using C-FRP sheets (widely used technique). Extensive comparisons and discussion of the test results derive new quantitative and qualitative results concerning the seismic capacity and the service life extension of the strengthened RC members using the proposed retrofitting scheme.

Modeling of Chloride Ion Diffusion in Concrete under Fatigue Loading

2018 ◽  
Vol 23 (1) ◽  
pp. 287-294 ◽  
Author(s):  
Tao Yang ◽  
Bowen Guan ◽  
Guoqiang Liu ◽  
Yanshun Jia
Keyword(s):  
Chloride Ion ◽  
Fatigue Loading ◽  
Ion Diffusion ◽  
Chloride Ion Diffusion

EFFECT OF CRUMB RUBBER ON CONCRETE STRENGTH AND CHLORIDE ION PENETRATION RESISTANCE

2015 ◽  
Vol 77 (32) ◽  
Author(s):  
Nurazuwa Md Noor ◽  
H. Hamada ◽  
Y. Sagawa ◽  
D. Yamamoto
Keyword(s):  
Structural Strength ◽  
Salt Water ◽  
Chloride Ion ◽  
Crumb Rubber ◽  
Rubberized Concrete ◽  
Migration Test ◽  
Ion Diffusion ◽  
Steady State Condition ◽  
Chloride Ion Penetration ◽  
Chloride Ion Diffusion

This paper present the effect of crumb rubber on its ability to produce concrete with structural strength when it was used directly from the plant without any treatment process. Crumb rubber was added as fine aggregates at 0%, 10%, 15% and 20% of sand volume meanwhile silica fume was added at 10% by cement weight. Three main series of concrete namely rubberized concrete with water-to-cement ratio of 50% and 35% was design and development of compressive strength was observed from day 7 until 91 days. Also, effectiveness of crumb rubber under flexural strength and splitting tensile strength was studied at 28 days curing age. Effect of crumb rubber on durability performance was done on chloride ion penetration resistance performance by migration test and by immersion in salt water. Chloride ion diffusion in rubberized concrete by migration test was carried out under steady state condition using effective diffusion coefficient, De meanwhile, immersion test in salt water was conducted under non-steady state condition using apparent diffusion coefficient, Da. Results showed that compressive strength was decrease with the increasing of crumb rubber in the mixture.  Even though the strength were reducing with the inclusion of crumb rubber, the reduction were less than 50% and it achieved acceptable structural strength. Chloride transport characteristics were improved by increasing amount of CR and rubberized concrete with w/c = 0.35 gave better resistance against chloride ion compared to w/c = 0.50 with more than 50% difference. Silica fume provide slightly strength increment compared to normal rubberized concrete and the same behavior was observed during chloride ion diffusion test.

Initial Implementation of IHI Zone Logic Technology at Philadelphia Naval Shipyard

1989 ◽  
Vol 5 (02) ◽  
pp. 79-89
Author(s):  
Koichi Baba ◽  
Takao Wada ◽  
Soichi Kondo ◽  
M. S. O'Hare ◽  
James C. Schaff
Keyword(s):  
Service Life ◽  
Life Extension ◽  
Initial Application ◽  
Initial Implementation ◽  
Late Fall ◽  
The Future ◽  
Service Life Extension ◽  
Extension Program ◽  
Technical Services

Philadelphia Naval Shipyard's application of zone logic to ship overhaul is neither small nor isolated. PNSY started its implementation of zone logic in the late fall of 1986, targeting the Service Life Extension Program (SLEP) for USS Kitty Hawk (CV-63) as the initial application. The technical services of Ishikawajima-Harima Heavy Industries Co., Ltd. (IHI), Japan were contracted to assist in this transition. This implementation on the Kitty Hawk is not a trial effort but involves about one third of the production man-days and covers over one half of the compartments on the ship. The actual SLEP production work on Kitty Hawk began in January 1988. Even though it is early in the three-year SLEP, zone logic already is proving its worth. This paper explains the zone logic methods and methodology applied at PNSY on Kitty Hawk. It also discusses the future of zone logic at PNSY and its continued application.

scholarly journals Sensitivity of Service Life Extension and CO2 Emission due to Repairs by Silane Treatment Applied on Concrete Structures under Time-Dependent Chloride Attack

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Aruz Petcherdchoo
Keyword(s):  
Service Life ◽  
Concrete Structures ◽  
Treatment Strategies ◽  
Time Dependent ◽  
Life Extension ◽  
Silane Treatment ◽  
Application Time ◽  
Free Service ◽  
Chloride Attack ◽  
Service Life Extension

This paper presents sensitivity of service life extension and CO2 emission due to silane (alkyltriethoxysilane) treatment on concrete structures under time-dependent chloride attack. The service life is predicted by the Crank–Nicolson-based finite difference approach for avoiding the complexity in solving Fick’s second law. The complexity occurs due to time-dependent chloride attack and nonconstant diffusion coefficient of concrete with silane treatment. At the application time of silane treatment, the cumulative CO2 emission is assessed. The effectiveness of silane treatment is defined as the ratio of the service life extension to the cumulative CO2 emission assessed within the corrosion-free service life. The service life extension is defined as the difference between corrosion-free service life of concrete structures without and with time-based application of silane treatment. From the study, the diffusion of chlorides in concrete with silane treatment is found to be retarded. In comparison, the strategy without deterioration of silanes during effective duration is more suitable for service life extension but less effective than that with deterioration. In the sensitivity analysis, there are up to eight parameters to be determined. The service life of concrete structures without silane treatment is most sensitive to the water-to-cement ratio and the threshold depth of concrete structures. Considering only five parameters in silane treatment strategies, the service life is most sensitive to the first application time of silane treatment. The cumulative CO2 emission is most sensitive to either the first application time of silane treatment or the amount of CO2 emission per application.

Sign in / Sign up

Export Citation Format

Share Document