Surface Texture of Roller Compacted Concrete Pavement

An iiiteiisive iesearch on roller compacted concrete pavement for high speed roads has been conducted in China since the beginning of this decade. Many technical reports document that the surface of RCCP is smooth due to the effect of the roller, and texturing such dry and less workable material is very difficult. Therefore, along with the material requirement and construction technique, the surface characteristics of this kind of pavement were also included in our research program: the formation, development and durability of surface texture. Several trial road sections were constructed to investigate the methods of macro-texture formation. Exposure by means of retarding agent spray, and water spray, aggregate embedding, grooving and other methods were tested in these trials. Furthermore, to solve the problem of micro-texture, special layer of high PSV stone was added by modifying ABG paver. The texture depth(TD), the side force coefficient(SFC) and the pendulum number(PN) between different treatments were compared in up to three years' time. The main findings are: (1) Exposure by means of retarding agent spray can increase the texture depth by 60<<80%. Before the opening to traffic, the TD of this treatment is in the range of 0.5<<0.8 mm. (2) The trend of TD development is increase and it is more remarkable for the treatment of water spray. For instance, TD of this kind of treatment could increase from 0.3 mm to 0.8 mm in one year I s time, but it would take non-treatment surface 3 or 4 years to reach the level. (3) Contrary to TD, both SFC and PN follow the trends of decrease, and are stable in about 2 years I time.