Emulsion sealing is a method of making sprayed seals in many countries including UK, USA and France. More recently in New Zealand emulsions have been mainly used for two coat seals. Emulsion seals have potential to be used under a range of conditions and with a range of stone sizes for single coat seals. Safety considerations and the general need to be environmentally responsible have pushed Fulton Hogan to emulsion sealing as a solution. Polymer emulsions have been used to extend seal performance for some years, however cost considerations make polymer modification undesirable in some situations. Emulsions are chemical systems and surfactant development has been intense in the last decade. This work examines the coalescence in emulsion aggregate systems and develops methods to measure stone retention under various conditions of cure. The effect of emulsion characteristics, such as particle size distribution, and emulsifier type are examined. Emulsions which can be controlled for break and cure under widely varying conditions can be formulated. Control of inversion, wetting and particle size are very important in emulsion performance. These aspects are discussed as well as the test methods developed. (a) For the covering entry of this conference, please see ITRD abstract no. E217100.
Samenvatting