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Title |
A Study on the Bond Strength of Coated Rebar by Polymer Cement Slurry Made of EVA and Ultra High-Early Strength Cement
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Authors |
형원길(Won-gil Hyung) ; 조영국(Young-Kug Jo) |
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DOI |
http://dx.doi.org/10.4334/JKCI.2015.27.6.633 |
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Keywords |
폴리머 시멘트 슬러리 ; 부착강도 ; 폴리머 시멘트비 ; 도장두께 ; 양생재령 polymer cement slurry ; bond strength ; polymer-cement ratio ; coating thickness ; curing age |
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Abstract |
Polymer cement slurry (PCS) is made from organic polymer dispersion and cement has good adhesion to steel, waterproofness and acid resistance due to being of polymer films formed in cement slurry. The purpose of this study is to evaluate the bond strength of coated rebar by polymer cement slurry made of EVA and ultra high-early strength cement. The test pieces are prepared with EVA polymer dispersion and ultra high-early strength cement having four types of polymer-cement ratios, four types of coating thicknesses and four curing ages, 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, and coating thicknesses of 75 μm and 100 μm. The maximum bond strength of PCS-coated rebar with ultra high-early strength cement and EVA at polymer-cement ratio of 80%, and coating thickness of 100 μm is about 1.32 and 1.38 times respectively, the strength of uncoated rebar and epoxy-coated rebar. It is apparent that the curing age, coating thickness, type of polymer and cement are very important factors to improve the bond strength of PCS-coated rebar to cement concrete. We can have basic information that PCS-coated rebar with polymer-cement ratio of 80% or 100% and coating thickness of 100 μm at curing age of 1-day can replace epoxy-coated rebar.
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