Hydrochloric and orthophosphoric acids use in the quick-traffic slurry surfacing mix

This article is devoted to development and production (on a lab emulsion plant) of six compositions of slow-setting bitumen emulsions for a slurry-surfacing mix. An aggregate composition for Type 1 (0-5 mm) and Type 3 (0-15 mm) slurry-surfacing mixes was determined and selected. Results of the slurry surfacing mix composition selected by the criteria of a mixture decay, cohesion strength build-up rate and material loss by wet track abrasion testing - on the basis of bitumen emulsions produced from both distilled and oxidized bitumen, using various emulsifiers and both hydrochloric and orthophosphoric acids, are presented in the article. Advantages of using slurry-surfacing mixes based on emulsion produced with orthophosphoric acid and Redicote C-320E emulsifier were proved. Such a system either minimizes or eliminates in its composition the use of the mixture decomposition regulator and reduces the content of Portland cement. The application of such a system makes it possible to produce slurry surfacing mix on the basis of low acid oxidized bitumen made from light petroleum and rock material through the criterion of the total surface activity determined by methylene blue with high rates of mix curing, and consequently the transport rapid start on the arranged thin-layer coating. Besides, the wet track abrasion indices of this system are substantially lower than in traditional system on oxidized bitumen, and even lower in comparison with the system on distilled bitumen.