Concrete Requirements for Ultra-Thin Concrete (Whitetopping) for Flexible Pavements

Whitetopping solutions for old flexible asphalt pavement overlays have been a challange for highway agencies and designers in the recent past years, with special regards to ultra-thin concrete overlays, also called by ultrathin whitetopping (UTW). Considering the needs of full bond between the UTW and the old asphalt concrete (AC) layer it is clear the impossibility of applying conventional theories for the calculation of bending stresses of such thin slabs. Moreover, UTW demands for high strength concretes in order to hold up more severe flexural stresses than the coiiveutiuttal Loud -etc slabs. This paper deals with the requirements for rcsistanc.e,s of a concrete to be employed as UTW, taking as case study square slabs with fixed dimension of 1,20 meters and a dual tire single axle of 100 kN. The study has shown significant differences for stresses due to load position and old asphalt layer thickness; a review of recent literature concerning high performance concrete for paving is presented and confronted with the theoretical results.