FULL DEPTH ASPHALT SOLVES ROAD RECONSTRUCTION PROBLEMS IN ESSEX

Delays to traffic caused by repairs often cost more than the cost of repairing and strengthening the pavement. Full depth asphalt reconstruction provides a quicker method which lasts longer and can be less expensive than conventional methods. The authors describe how full depth asphalt was used to reconstruct two heavily trafficked routes leading to the docks, the other avoiding a town centre. Thick layers can be excavated, filled with asphalt, compacted and opened to traffic within a few hours. There are less delays due to bad weather and a smaller quantity of material is needed. Bituminous bound material has a greater structural strength because it does not allow water into the pavement and it reduces the effects of freezing on the sub-grade. In both cases, at the sites mentioned, the pressure of service near the surface prevented the laying of the thickness suggested by conventional Road Note 29 designs. The stronger pavement also allowed the passage of construction traffic and buses immediately after laying and compaction of the 90mm thick first course of the structural layer. The economies of stage construction could also be achieved with a modified short life full-depth construction. (Author/TRRL)