Fabrication of solvent-free asphalt emulsion prime with high penetrative ability

Abstract

Solvent-free asphalt emulsion is preferred as the prime coat in pavement engineering. However, the solvent-free asphalt emulsion usually has quite poor penetrative ability. To fabricate solvent-free asphalt emulsion with high penetrative ability, several asphalt emulsions were fabricated by changing the composition parameters including emulsifier, asphalt, and wetting agent, which may affect the particle size of asphalt droplets and the viscosity and wetting ability of emulsion. Then, the penetrative ability of these emulsions into a typical material for the base layer as well as the corresponding mechanisms were investigated by conducting the tests of penetration depth, contact angle and particle size distribution. Results indicate that the addition of wetting agent (JFC, a fatty alcohol-polyoxyethylene ether) can greatly increase the penetration depth of asphalt emulsion because it can sharply increase the wetting ability of asphalt emulsion. The use of high emulsifier content effectively reduces the particle size of the asphalt droplets, thus greatly improving the penetrative ability of asphalt emulsion. Besides, when asphalt emulsion with high emulsifier content is diluted to a constant asphalt content, moderately increasing asphalt content in production can narrow the particle size distribution of asphalt droplets and enhance the penetrative ability of asphalt emulsion. In general, when high emulsifier content, relative high asphalt content in production, and wetting agent are all employed during the fabrication process, the asphalt emulsion can have both a good penetrative ability and bonding ability at normal asphalt content.