Abstract
In general, polymer cement slurry(PCS) that is made from organic polymer dispersion and cement has good adhesion to steel and cement concrete, waterproofness and acid resistance due to being of polymer films formed in cement slurry. The purpose of this study is to evaluate the effects of early curing age and coating thickness of polymer cement slurry-coating material on the bond strength of rebar to cement concrete. The test pieces are prepared with two types of polymer dispersions such as St/BA and EVA, four polymer-cement ratios, two types of cement, four coating thicknesses and three 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 plain rebar and epoxy-coated rebar. It is also high bond strength at curing ages of 7-day or less, and coating thicknesses of $75{\mu}m$ and $100{\mu}m$. The maximum bond strength of PCS-coated rebar at curing age of 1-day and 3-hour is almost same as that of curing age of 7-day. It is possible that PCS-coated rebar with curing age at 1-day and 3-hour and costing thickness of $75{\mu}m$ and $100{\mu}m$ can replace epoxy-coated rebar. It is apparent that the choice of curing age and coating thickness is very important to improve the bond strength of PCS-coated rebar to cement concrete.
