| 摘要 |
PURPOSE:To provide the titled compsn. which has good adhesion between a binder and aggregate, does not cause rapid curing nor thickening and gives durable pavament with good workability, by adding a specified urethane prepolymer having an isocyanate group at its teriminal. CONSTITUTION:A urethane prepolymer contg. 3-15wt% isocyanate groups at the terminals of its branched molecular structure obtd. by reacting a starting polyol (a) having a hydroxyl value of 20-250mg KOH/g and composed of a mixture of 20-80wt% polyoxyalkylene polyol and 80-20wt% polybutadiene polyol with a starting diisocyanate (b) consisting of methylene-bisphenyl diisocyanate and/or tolylene diisocyanate, is used. 1-10wt% said urethane prepolymer is mixed with asphalt by heating. An aggregate, etc. are mixed with the resulting mixture to obtain the desired paving asphalt mixture.
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