Results of the field evaluation of five experimental binders used to produce cold-stockpiled patching materials for repairs in cold and wet weather are described. The materials were compared against an mc-800 cutback control mix. The experimental mixes were made with a latex-modified mc-800 cutback and four high-float, medium-set (hfms) emulsion binders. One of the hfms binder mixes contained fibers. The procedures were specifically designed to minimise the likelihood that variables other than the binder were the proximate cause of repair failures. The failure criteria used are also described. Field evaluations were made from march 1986 to may 1987. Two hfms mixes performed better than the companion control mix. Because the latex-modified cutback mix did not perform satisfactorily, no further development was recommended. An economic analysis showed that premium mixes need only extend the average service life by a modest amount to provide a lower annualised cost than conventional mixes. For example, a $120/ton mix lasting 2 years provides substantial savings compared to a $30/ton mix lasting 1 year. Extended field trials of stockpiled mixtures using hfms binders are recommended. Field trials using fibers are also recommended. This paper appears in transportation research record no. 1268, Highway maintenance operations and research 1990.
Samenvatting