scholarly journals An 18-Month Analysis of Bond Strength of Hot-Dip Galvanized Reinforcing Steel B500SP and S235JR+AR to Chloride Contaminated Concrete

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 747
Author(s):  
Mariusz Jaśniok ◽  
Jacek Kołodziej ◽  
Krzysztof Gromysz
Keyword(s):  
Comparative Analysis ◽  
Bond Strength ◽  
Complex Geometry ◽  
Zinc Coating ◽  
3D Scanning ◽  
Steel Grade ◽  
Electrochemical Tests ◽  
Test Elements ◽  
Steel Rebars ◽  
Chloride Contaminated

This article describes the comparative analysis of tests on bond strength of hot-dip galvanized and black steel to concrete with and without chlorides. The bond effect was evaluated with six research methods: strength, electrochemical (measurements of potential, EIS and LPR), optical, and 3D scanning. The tests were conducted within a long period of 18 months on 48 test elements reinforced with smooth rebars ϕ8 mm from steel grade S235JR+AR and ribbed rebars ϕ8 mm and ϕ16 mm from steel grade B500SP. The main strength tests on the reinforcement bond to concrete were used to compare forces pulling out galvanized and black steel rebars from concrete. This comparative analysis was performed after 28, 180, and 540 days from the preparation of the elements. The electrochemical tests were performed to evaluate corrosion of steel rebars in concrete, particularly in chloride contaminated concrete. The behaviour of concrete elements while pulling out the rebar was observed using the system of digital cameras during the optical tests. As regards 3D scanning of ribbed rebars ϕ8 mm and ϕ16 mm, this method allowed the detailed identification of their complex geometry in terms of determining the polarization area to evaluate the corrosion rate of reinforcement in concrete. The test results indicated that the presence of zinc coating on rebars had an impact on the parameters of anchorage. In the case of ribbed rebars of 16 mm in diameter, the maximum values of adhesive stress and bond stiffness were reduced over time when compared to black steel rebars. Moreover, it was noticed that the stiffness of rebar anchorage in chloride contaminated concrete was considerably higher than in concrete without chlorides.

scholarly journals Effect of the degree of corrosion on bond performance of Cement Polymer Composite (CPC) Coated steel rebars

2018 ◽  
Vol 199 ◽  
pp. 04010
Author(s):  
Deepak K. Kamde ◽  
Radhakrishna G. Pillai
Keyword(s):  
Bond Strength ◽  
Polymer Composite ◽  
Continuous Monitoring ◽  
Coated Steel ◽  
Bond Performance ◽  
Pull Out ◽  
Curing Period ◽  
Uncoated Steel ◽  
Concrete Coating ◽  
Steel Rebars

Currently, large infrastructures (bridges, highways, etc.) are designed for more than 100 years. To achieve long service life, coated rebars (mostly, cement polymer composite (CPC) coated rebars) are being used to enhance the corrosion resistance. However, inadequately coated rebars can lead to premature corrosion. This can also affect the bond between the rebar and the concrete. To assess the effect of CPC coating on bond strength, pull-out specimens of (150×150×100) mm with 12 mm diameter rebar with 100 mm embedded length were cast and tested. For this, three replica specimens with two types of reinforcement namely, i) Uncoated steel ii) CPC coated steel were cast. To induce corrosion, additional five specimens with CPC coated steel rebars were cast with premixed chloride and cured for 28 days. During the curing period, continuous monitoring of corrosion potential and rate was done and degree of corrosion was assessed. The effect of degree of corrosion on bond of steel-concrete-coating interface was quantified. The CPC coated rebars without corrosion exhibited 10% bond reduction. CPC coated rebars with corrosion exhibited 30-70% reduction in bond strength. Also, the corrosion is found to adversely influence the stiffness of the bond.

scholarly journals Evaluation of Cathodic Protection Criteria for Embedded Steel Reinforcement in concrete structures

2018 ◽  
Vol 7 (3.12) ◽  
pp. 333 ◽  
Author(s):  
Hirudayasamy Dolli ◽  
Andiappan Kavitha ◽  
Jeevarose .
Keyword(s):  
Cathodic Protection ◽  
Conductive Polymer ◽  
Concrete Slabs ◽  
Corrosion Initiation ◽  
Electrochemical Interface ◽  
Atmospheric Exposure ◽  
Drying Conditions ◽  
Steel Rebars ◽  
Sacrificial Protection ◽  
Chloride Contaminated

This paper presents the results of performance of sacrificial protection in preventing the rebar corrosion in chloride contaminated and chloride free concrete. In this present study, the effectiveness of sacrificial protection of embedded steel rebars has been evaluated on chloride contaminated and chloride free concrete slabs using ribbon type Zinc anodes with ion conductive polymer backfill over a period of 250 days of exposure. The results showed that the ribbon type zinc sacrificial anodes with the navel electrochemical interface (Ion conductive polymer backfill) can confer effective corrosion protection of embedded steel in concrete on preventing corrosion initiation in chloride contaminated as well as chloride free concretes slabs. The cathodic protection criteria evaluated on concrete unit slab showed that 100-150mV is necessary in the atmospheric exposure and 160-200mV under alternate wetting & drying conditions. 

Corrosion mitigation of steel rebars in chloride contaminated concrete pore solution using inhibitor: An electrochemical investigation

2018 ◽  
Vol 173 ◽  
pp. 443-451 ◽  
Author(s):  
Han-Seung Lee ◽  
Hyun-Min Yang ◽  
Jitendra Kumar Singh ◽  
Shailesh Kumar Prasad ◽  
Bongyoung Yoo
Keyword(s):  
Pore Solution ◽  
Electrochemical Investigation ◽  
Steel Rebars ◽  
Chloride Contaminated

scholarly journals Effect of Placing Self-Compacting Concrete Bottom up on the Quality of Bond Conditions

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2346
Author(s):  
Milena Kucharska ◽  
Piotr Dybeł
Keyword(s):  
Alternative Methods ◽  
Bond Properties ◽  
Self Compacting Concrete ◽  
Bottom Up ◽  
Pull Out ◽  
Test Elements ◽  
Concrete Elements ◽  
Steel Rebars ◽  
Bond Tests

A self-compacting concrete (SCC) mixture, due to its special rheological properties, may be placed differently than in traditional variants. The paper presents the results of a study on the effect of a bottom-up placing direction on the quality of bond conditions between steel and self-compacting concrete. Elements with overall dimensions of 160 × 480 × 1600 mm consisting of elementary samples with dimensions of the bond test basic modules were constructed. Ribbed steel rebars with diameters of 16 mm were used and located in formworks perpendicularly to the concrete placing direction. Bond tests were carried out according to the pull-out method. The bottom-up placing contributed to the uniformity of the bond conditions quality in the test elements and an overall improvement of the bond properties, especially in its top part. Given the increasing implementation of alternative methods of mix placing and the promising results, the topic should be further investigated.

Semisolid Forging of 250 Automotive Spindles of S48C Steel

2019 ◽  
Vol 285 ◽  
pp. 411-416 ◽  
Author(s):  
Jokin Lozares ◽  
Gorka Plata ◽  
Iñaki Hurtado ◽  
Zigor Azpilgain ◽  
Iñigo Loizaga
Keyword(s):  
Complex Geometry ◽  
Steel Grade ◽  
Raw Material ◽  
Material Consumption ◽  
High Quality ◽  
Production Processes ◽  
Global Trend ◽  
Reduction Of Emissions ◽  
Manufacturing Technologies

Nowadays, globalisation enables a rapid uptake of the classical manufacturing technologies. In order to remain competitive and fulfil the global trend of reduction of emissions, innovative production processes that reduce the energy and raw material consumption should arise. Semisolid forging (SSF) is one of those techniques with great potential to fulfil those requirements maintaining the high quality of the components. Thus, the objective of this work is twofold: to produce a complex geometry part saving material and energy using the off-the-shelf S48C steel grade, and to demonstrate the capability of the process to produce a pre-series of 250 components without excessive tooling damage.

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