As part of the Area 13 Framework contract; Aggregate Industries, Highways England, and Kier have worked in collaboration to undertaken the UK’s first Hot-on-Hot in line paving trial. The trial was undertaken on the M6 Junction 36-35 S/B C/W at Burton to Cinderbarrow on the 27thand 28th July 2016.
Hot-on-Hot is a new concept in the UK but is widely used in Germany on most major roads. The principals behind the operation are to lay two asphalt layers at the same time, Binder Course and Surface Course, forming a fully homogenous layer.
The Binder Course layer is compacted with a high compaction screed giving full compaction throughout the layer. The Surface Course material is laid directly behind using a transfer vehicle to feed the material into the paver, this is then compacted as normal using standard equipment. Utilising the material transfer vehicle allows for continuous paving of the Surface Course layer resulting in an outstanding ride profile.
The benefits of carrying out works in this fashion is that the layers form a fully bonded pavement creating a single layer out of two different products. This not only gives a fully water tight interface, eliminating any possible bonding failures, but shows a cost saving due to a reduction in the more expensive surface course material and bond coat applied.
On this particular site the original specification was for 60mm of Binder Course and 40mm of Surface Course, by using the Hot-on-Hot system the material thicknesses where changed to 70mm of Binder Course and 30mm of Surface Course.