scholarly journals Long-Term Performance of Seawater Sea-sand Concrete (SSC) Columns Wrapped with CFRP Strips Under Simulated Marine Environment

2022 ◽  
Vol 2148 (1) ◽  
pp. 012039
Author(s):  
Junlong Yang ◽  
Ziru Wang ◽  
Jizhong Wang
Keyword(s):  
Marine Environment ◽  
Concrete Strength ◽  
Failure Process ◽  
Natural Seawater ◽  
Test Results ◽  
Reinforced Polymer ◽  
Sea Sand ◽  
Long Term Performance ◽  
Term Performance

Abstract This article presents a durability study of carbon fiber-reinforced polymer (CFRP) partially wrapped seawater sea-sand concrete (SSC) columns exposed to natural seawater to explore the effect of exposure duration on the long-term performance of the specimens. Thirty-two cylinders were wrapped with CFRP jackets and exposed to different times of wet-dry cycles (up to 360 days) in an outdoor simulated marine environment. Test results indicate that exposure has no obvious influence on the failure process and ultimate strains of specimens, but the compressive strengths of confined columns (fcc) increase with the increment of exposure time, especially for the partially confined concrete specimens. Moreover, due to the significant variation of unconfined concrete strength fco*), the retentions of fcc and fcc/fco * exhibit an opposite trend. Therefore, the increase of fco* should be considered when using the parameter of the confined-to-unconfined ratio of strength to evaluate the long-term performance of the specimens.

Crevice Corrosion Studies on Corrosion Resistant Alloys in Stagnant Natural Seawater

2012 ◽  
Vol 610-613 ◽  
pp. 276-279
Author(s):  
Laura L. Machuca ◽  
Stuart I. Bailey ◽  
Rolf Gubner
Keyword(s):  
Crevice Corrosion ◽  
Corrosion Potential ◽  
Natural Seawater ◽  
Corrosion Resistant ◽  
Testing Procedures ◽  
Corrosion Studies ◽  
Long Term Performance ◽  
Term Performance ◽  
Positive Effect

Crevice corrosion (CC) was investigated for a number of selected corrosion resistant alloys in natural seawater containing microorganisms for up to 18 months under stagnant conditions. Experimental controls consisted of tests in natural seawater filtered in accordance with hydrostatic testing procedures. The corrosion potential of alloys was monitored throughout exposure and corrosion was evaluated by weight loss and 3D optical microscopy. CC was initiated on several alloys and corrosion rates in time indicated a positive effect of seawater filtration on the long-term performance of the alloys. Microbial adhesion, as indicated by fluorescence microscopy, occurred mainly outside the crevice and differed according to the nature of the substratum surface.

scholarly journals Long-term Performance of Concrete under Marine Environment

2001 ◽  
Vol 39 (10) ◽  
pp. 17-24
Author(s):  
H. Hamada ◽  
T.U. Mohammed ◽  
T. Yamaji ◽  
H. Watanabe
Keyword(s):  
Marine Environment ◽  
Long Term Performance ◽  
Term Performance

scholarly journals Long-term Performance of Nanoparticle Incorporated Eco-friendly Concrete in Natural Seawater Environment

2021 ◽  
Author(s):  
John Philip ◽  
Manu Harilal ◽  
Anandkumar Balakrishnan ◽  
Rani Pongachira George ◽  
Shaju Kattukaran Albert
Keyword(s):  
Order Reduction ◽  
Chloride Content ◽  
Total Biomass ◽  
Natural Seawater ◽  
Free Chloride ◽  
Lower Chloride ◽  
One Year ◽  
Long Term Performance ◽  
Term Performance

Abstract The use of blended concrete has widely gained industrial importance owing to the CO2 gas emissions and carbon footprint resulting from the production of ordinary Portland cement (OPC). Despite the advancements, the deterioration of concrete structures raises a significant threat to their long term durability and service life in aggressive conditions. In this work, the long-term antifouling, strength and durability properties of a blended eco-friendly concrete with OPC, fly ash, nanoparticles, and corrosion inhibitor is evaluated in natural seawater for one year. The biofouling attachment, total viability count (TVC), mechanical strength, alkalinity and free chloride contents were measured and the results were compared with OPC concrete. A four-order reduction in the total biomass and total bacterial density is observed on the surface of the blended concrete. Further, a significantly lower chloride and water penetration depth, free chloride content, compact and smooth surface morphology devoid of cracks and high C-S-H content are observed in blended concrete, compared to the OPC concrete, after exposure in seawater for one year. From the results, it is seen that the blended concrete mix is promising for applications in seawater environments because of its superior biofouling resistance, mechanical properties and durability.

Durability of Glass Fiber Reinforced Polymer (GFRP) Bar Used as Concrete Reinforcement: Temperature Effect

2011 ◽  
Vol 94-96 ◽  
pp. 1573-1576 ◽  
Author(s):  
Jian Wei Huang
Keyword(s):  
Service Condition ◽  
Fiber Reinforced Polymer ◽  
Average Temperature ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Rc Structure ◽  
Yearly Average ◽  
Long Term Performance ◽  
Term Performance

This paper presents calibration of service temperature on the prediction of long-term performance of GFRP bar in reinforced concrete structures. Two approaches, based on monthly average temperature and yearly average temperature are proposed to simulate the real service condition on the RC structure for the study on long-term performance. A design example for the comparison of results by the two approaches is presented.

An Investigation of Environmental Reduction Factor for GFRP Bar Used as Concrete Reinforcement in China

2011 ◽  
Vol 413 ◽  
pp. 399-403 ◽  
Author(s):  
Jian Wei Huang
Keyword(s):  
Reduction Factor ◽  
Fiber Reinforced Polymer ◽  
Rc Structures ◽  
Average Temperature ◽  
Reinforced Polymer ◽  
Gfrp Bar ◽  
Temperature Records ◽  
Long Term Performance ◽  
Term Performance

Currently, an environmental reduction factor (ERF) is incorporated in design codes/guidelines of Fiber Reinforced-Polymer (FRP) in reinforced concrete (RC) structures to account for the FRP long-term durability. Due to the lack of real time durability data, justification of the ERF is still necessitated. This paper presents a calibration of ERF for GFRP bar to be used in China on the basis of the prediction of GFRP long-term performance with monthly average temperature records from 32 major cities. Research results show that the ERF values vary from 0.49 to 0.58 at 100% R.H. exposure, while ERFs are greater than 0.70 for all cases being studied when R.H. is below 90%. On the basis of this study, ERF can be recommended as of 0.70 and 0.50 for application with R.H. <90% and moisture saturated exposures, respectively.

State DOT Implementation of Statistical Analysis and Percent Within Limits

2019 ◽  
Vol 2673 (2) ◽  
pp. 583-592
Author(s):  
Aaron R. Coenen ◽  
James E. Pforr ◽  
Steven A. Hefel ◽  
Barry C. Paye
Keyword(s):  
Quality Assurance Program ◽  
Limiting Factor ◽  
State Agencies ◽  
Test Results ◽  
Department Of Transportation ◽  
Wisconsin Department ◽  
Integral Role ◽  
Long Term Performance ◽  
Term Performance

Verification testing, conducted by many state agencies, should serve an integral role in a quality assurance program. Many agencies seek a balance of physical and financial resources, as resources are routinely a limiting factor. For the Wisconsin Department of Transportation (WisDOT), it is datasets collected by both the contractor (quality control, QC) and department (quality verification, QV) at differing frequencies compared in a statistically valid method that provide balance. Statistical analyses, specifically F- and t-testing, have been chosen by WisDOT to accompany a Percent Within Limits (PWL) specification for hot mix asphalt (HMA). The analyses evaluate QC and QV data variances, means, standard deviations, and so forth, and determine whether it is reasonable to assume the test results of each dataset come from the same population, that is, are representative of the same material. If comparable, the more frequent QC data are considered verified and subsequently used in PWL calculations to approximate the percentage of material within specification limits. Anything less than comparable is subject to further investigation, for example, a dispute resolution process, to determine which test results most reliably represent the physical properties of the material, and are thus justifiably used in latter calculations. Such an approach has allowed WisDOT to adjust pay in accordance with material quality and consistency, ultimately connecting pay to anticipated long-term performance. This modified system of monitoring HMA materials has motivated multiple changes to industry processes and planning, and resulted in more consistent pavements, which should reduce the potential for isolated premature distresses.

Sign in / Sign up

Export Citation Format

Share Document