ABSTRACT
The Queen Elizabeth II Bridge over the Thames at Dartford is one of the most critical and heavily trafficked structures of the UK’s road network. The bridge was resurfaced in the summer of 2015 using high performance asphalts produced with a polymer modified binder. Two polymer modified binders were initially selected for laboratory evaluation. These two binders were used to design a surfacing consisting of a binder and a surface course mixture. The surfacing was evaluated in the laboratory using double layer or composite ie binder and surface courses, asphalt specimens. These specimens were prepared using a laboratory roller compactor by compacting first the binder course mixture and then the surface course on top. Deformation resistance was evaluated by means of cyclic triaxial and, static and cyclic indentation tests. The cyclic triaxial test was akin to typical traffic speeds whereas static and cyclic indentation tests simulated stationary and low speed traffic conditions. Monotonic and cyclic fracture tests on composite beam specimens cut from slabs were also carried out to evaluate crack propagation properties. Results from the laboratory work were then used to select the polymer modified binder that gave the best performance. Finally, resurfacing was carried out successfully using the proposed mixtures and polymer modified binder.
