Bond Strength of Polymer Cement Slurry-Coated Rebar Using EVA Latex in Cement Concrete

Abstract:

Polymer cement slurry(PCS) made from organic polymer dispersion and cement has good adhesion to steel, waterproofness and acid resistance due to being of polymer films formed in the cement slurry. The purpose of this study is to evaluate the mix conditions such as coating thicknesses, curing ages and polymer-cement ratios of PCS-coating material effected on improvement in bond strength of rebar coated by PCS with EVA latex in cement concrete. The test pieces are prepared with four types of polymer-cement ratio, four types of coating thickness and four types of curing age, and tested for the bond strength test. From the test results, in general, bond strength of PCS-coated rebar is better than that of uncoated rebar and epoxy-coated rebar. It is also high bond strength at curing ages of 7-day or less, and coating thicknesses of 75 µm and 100 µm. The maximum bond strength of PCS-coated rebar at curing age of 3-hour is almost same as that of curing age of 1-day and 7-day. The maximum bond strength of PCS-coated rebar with EVA at polymer-cement ratio of 50%, and coating thickness of 100 µm is about 1.41 and 1.47 times respectively, the strength of uncoated rebar and epoxy-coated rebar. It is apparent that the curing age, coating thickness and polymer-cement ratio are very important factors to improve the bond strength of PCS-coated rebar to cement concrete. We can have basic information that it can replace epoxy coated rebar by the PCS-coated rebar with curing age at 3-hour and coating thickness of 100 µm.

• Periodical: Advanced Materials Research (Volume 687)
• Pages: 175-184
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.687.175
• Online since: April 2013
• Authors: Young Kug Jo, Seon Ho Jeong, Wan Ki Kim
• Keywords: Bond Strength, Coating Thickness, Curing Age, Polymer Cement Slurry, Polymer-Cement Ratio

References

[1] Baweja O., Roper H. and Sirivivatnanon V. Chloride-induced steel corrosion in concrete: part-1-Corrosion rates, corrosion activity, and attack areas, ACI materials Journal, 3(1998)207-217.

DOI: 10.14359/364

[2] So S. and Soh. Y. Measuring methods of chloride ion content in hardened concrete, Annual report of Korea Infrastructure Safety and Technology Corporation, (1999)10-20.

[3] Andrade C. Monitoring techniques, in corrosion of steel in concrete, Report of the technical Committee 60-CSC, RILEM, Chapman and Hall, (1998)79-97.

[4] Ohama Y. Handbook of Polymer-Modified Concrete and Mortars, Noyes Publication, Park Ridge, New Jersey, 1995.

[5] ASTM Committee A-1, Standard specification for epoxy-coated reinforcing bars, Annual Book of ASTM Standards, 1(1997)404-410.

[6] Yu S. Test on transfer bond performance of epoxy coated prestressing strands, Journal of the Korea Concrete Institute, 6(1994)89-100.

[7] Darwin D., Mccabe S. L. and Choi O. Evaluation of Bond performance of Epoxy-Coated Reinforcing Steel using Nonlinear Finite Element Analysis, Proceedings, ASCE material Congress, Denver, CO,(1990)135-144.

[8] Shin Y. and Choi. O. Bond Properties of Epoxy Coated Bars in High Strength Concrete, Journal of the Architectural Institute of Korea, 6(1997)209-14.

[9] Oh B., Joo Y. and Jee O. An experimental study on corrosion resistance of epoxy coated reinforcements, Journal of the Korea Concrete Institute, 4(1992)61-70.

[10] Jo Y., Kim Y. and Soh Y. Effects of corrosion conditions on the adhesion of coated steels with polymer cement slurry, Journal of the Architectural Institute of Korea, 19(2003).77-84

[11] ACI Committee 548, Abstract of : State-f-the-art report on Polymer-Modified Concrete, ACI materials Journal, (1998)725-34.

[12] Jo Y. and Jeong S. A study on the performance tests of polymer cement slurry-coated steels, Journal of the Korean Society of Civil Engineers, 28(2007)759-69.

[13] Jo. Y. A study on the bond performance and anti-corrosion of polymer cement composites coated steel, Journal of the Architectural Institute of Korea, 22(2006)101-108.

[14] Jo. Y. Tensile properties and adhesion of hybrid-type anti-corrosion polymer cement slurry, Journal of the Korea Concrete Institute, 20(2008)635-642

DOI: 10.4334/jkci.2008.20.5.635

[15] Jo. Y. Adhesion and impact properties of polymer cement slurry-coated steel plate and deformed bar, Journal of the Architectural Institute of Korea, 26(2010)91-100.

[16] Jo. Y., Park. D. and Jang. G.. Effect of mix proportions and coating thickness on the bond strength of coated rebar by polymer cement slurry. Journal of the Architectural Institute of Korea, 6(2011)107-114.

[17] CEB-FIP, CEB-FIP model code 1990, Thomas Telford, 1992.

DOI: 10.1680/ceb-fipmc1990.35430.0009

[18] KCI Concrete Structure Code, Korean Concrete Institute, 1999.

[19] ACI Committee 408-03, Bond and Development of Straight Reinforcing Bars in Tension, Farmington Hills, M1: American Concrete Institute, 2003.