ABSTRACT
ABSTRACT. The exposed aggregate construction technique is not new. It was first used in Belgium over twenty years ago to texture concrete roads. The Austrians refined the process in order to achieve low noise concrete running surfaces and their work has been modified and improved to suit UK conditions and specifications. Now commonly known as ’whisper concrete’, this concrete surface has been the subject of two full scale construction trials undertaken by the Highways Agency (formerly DOT). The first, on the Ml 8 in Humberside, was constructed late in 1993. TRL conducted the noise and skidding resistance tests. The paper demonstrates how the low noise level of the exposed aggregate surface was achieved whilst maintaining a satisfactory high-speed skidding performance. A second, longer section of exposed aggregate concrete was paved in late 1994 as part of the A50 Foston-Hatton-Hilton By pass, near Derby. This surface has also been evaluated by TRL, on behalf of the Highways Agency. The paper examines the background to the trials and their national importance. The differences between UK requirements and those elsewhere in Europe are explained and the construction methods used on both contracts are detailed. The preliminary results are discussed and the future for this method of paving is considered.
