An Investigation on Mechanical Properties and Bonding Strength of Polymer Concretes and Polymer Modified Concretes as Repair Overlays on Concrete Substrate

Selection, design and control of materials are very important for achievement of a compatible, durable and economical repair overlay. Suitable bonding of repair overlay to substrate and good resistance against fracture are basics for a durable overlay. Using Polymer Concretes (PC) and Polymer Modified Concretes (PMC) which present great performance and durability can be considered as a method of restoration in damaged structures. In this research, mechanical properties and strengths of bonding to substrate concrete of Polymer Concretes and Polymer Modified Concretes as repair overlays are investigated and compared. Strength of Bonding to substrate concrete was obtained by Pull-Off test method. Bonding strength to substrate concrete in Polymer Concretes mix designs samples was weaker than Polymer Modified Concretes mix designs samples in similar conditions. In comparison with conventional concrete repair overlays in Pull-Off test, the maximum increment of bonding strength to substrate concrete was observed in mix design containing %50 of water replacement with SBR-based polymer which was %30 of increment and after that in mix design containing %50 of water replacement with Acrylic-based polymer which was %28 of increment. In Polymer Modified Concretes, %5 replacement of cement with Silica Fume decreased the amount of shrinkage but in higher values of replacement the amounts of shrinkage were increased in samples.