GB1344122A - Method of rubberizing asphalt - Google Patents

Abstract

1344122 Impregnating asphalt pavements with rubber PHILLIPS PETROLEUM CO 24 Feb 1971 5376/71 Headings C3Q QC6A QC14A QC14B QC12A QC17 and QD1A1 A method of impregnating with rubber the asphalt in an asphalt-aggregate pavement which has been previously laid, comprises applying an oil-inwater emulsion to the asphalt surface, the oil containing an elastomer in solution at a concentration of from 2-25 wt. per cent of the oil, the asphalt and elastomer being mutually soluble in the oil, the oil having an initial boiling point not substantially below about 300‹C at 760mm Hg, and the oil being substantially free of asphaltenes and substantially soluble in n-pentane. Preferably, the oil has a viscosity of at least 50 SUS at 212 degrees F, the elastomer content is between 2 and 15 wt. per cent of the oil, and the emulsion contains a cationic emulsifier. The elastomer may be natural rubber, a styrene-butadiene block copolymer, a synthetic cis-poly (isporene), SBR synthetic rubber or a transpoly (isoprene). The quantity of oil in the emulsion is preferably not mroe than one third the weight of asphalt being rubberized, the quantity of elastomer in the emulsion being preferably between 0À1 and 2À5 wt. per cent of the asphalt being rubberized. The preferred application rate E of the emulsion in gallons of emulsion per square yard of pavement per inch of pavement thickness to deposit elastomer in the pavement at a concentration of Z wt. per cent of the asphalt in the pavement is determined by the Formula: E=78 x Z/S x R where R is the wt. percentage of elastomer in the oil phase of the emulsion, and S equals the wt. percentage of the oil phase of the emulsion.