DURABLE BONDED HIGH PERFORMANCE – AND ULTRA HIGH PERFORMANCE CONCRETE TOPPINGS AND ULTRA THIN OVERLAYS

I'm writing an very detailed article and a report regarding bonded High Performance Concrete and Ultra High Performance Concrete toppings and overlays. While bonding and failure mechanisms are well investigated (J. Silfwerbrand,U.S. Department of the Interior Bureau of Reclamation, STAR 193-RLS 2011, U.S. Department of Transportation. Federal Highway Administration, recently Master of Science Thesis Maikel van Dooren and many others), not much research is made regarding bonding of High Performance Concrete and Ultra High Performance Concrete toppings and overlays. During 33 years’ experience with bonded and unbonded High Performance Concrete and Ultra High Performance Concrete toppings and overlays gave me a lot of information regarding failure and success. Today more and more companies are involved as supplier and contractor in the pouring of High Performance Concrete and Ultra High Performance Concrete toppings and overlays and I think that much can be learned from experiences from the past. By digging up my old paper files I found the still interesting publication from Densit A/S written in 1992 and published in January 1993. This publication of 5 pages is dealing with the map cracks (micro-cracks) at the surface appearing in the Densit floors when a good bonding was obtained and the information is still relevant and useful. While at that time the complex process of autogenous shrinkage was not known, we had to deal with large shrinkage (compared to a traditional concrete) in a very short period due to the fast strength development of the High Performance Concrete and Ultra High Performance Concrete toppings and overlays.