SLOAPCD RULE 420 CUTBACK ASPHALT PAVING MATERIALS
LAST REVISED 06/18/79



RULE 420. CUTBACK ASPHALT PAVING MATERIALS  (Adopted 6/18/79)

     A.   Compliance Dates

          1.   After July 1, 1979, no person shall cause or allow
               the use or application of rapid cure cutback
               asphalt for highway or street or maintenance, nor
               manufacture, sell or offer to sell cutback asphalt
               for such use or application.

          2.   After July 1, 1980, no person shall cause or allow
               the use or application of cutback asphalt for
               highway or street paving or maintenance, nor
               manufacture, sell, or offer for sale cutback for
               use or application except as specified below:

               a.   Where the cutback asphalt is to be used
                    solely as a penetrating prime coat;

               b.   Where the National Weather Service official
                    forecast of the high temperature for the
                    immediate vicinity of the asphalt application
                    for the 24-hour period following application
                    is below 50oF (10oC);

               c.   Where the cutback asphalt is to be used for
                    highway or street paving or maintenance
                    purposes and the location of such use is a
                    minimum of 25 miles from the nearest
                    available commercial plant which produces and
                    offers for sale plant mixed surfacing
                    material.

          3.   In non-attainment areas after January 1, 1982, no
               person shall cause or allow the use or application
               of an emulsified asphalt containing petroleum
               solvents (diluents) in excess of three percent by
               volume or cutback asphalt for highway or street
               paving or maintenance.  These provisions do not
               apply to cutback asphalt manufactured in this
               District for shipment and use outside this
               District.

               If by January 1, 1981, there are no suitable
               emulsified or slow cure asphalt alternatives
               available at a cost comparable to existing
               materials as approved by the APCD for uses listed
               in the exception under A.2, then the January 1,
               1982 date will be extended on a year-to-year basis
               until such materials are available.

          4.   After January 1, 1982, road oils used for highway
               or street paving or maintenance applications shall
               contain no more than 5.0% of organic compounds
               which boil at less than 500oF as determined by
               ASTM D402.

     B.   Definitions

          1.   "Asphalt" means oil asphalt or a homogenous
               mixture of refined liquid and solid asphalts
               suitable for use in the manufacture of asphalt
               concrete.

          2.   "Cutback asphalt" means paving grade asphalts
               liquefied with petroleum distillate and as further
               defined by American Society for Testing and
               Materials (ASTM) specifications as follows:
                    Rapid CureType:          ASTM D2028
                    Medium Cure Type:   ASTM D2027
          3.   "Dust palliative" means any light application of
               liquefied asphalt (cutback or emulsified asphalt)
               for the express purpose of controlling loose dust.

          4.   "Emulsified asphalt" means any asphalt liquefied
               with water containing an emulsifier.  The two
               kinds of emulsions most pertinent are the anionic
               and cationic types.

          5.   "Penetrating prime coat" means any application of
               asphalt to an absorptive surface to penetrate and
               bind the aggregate surface and promote adhesion
               between it and the new superimposed construction. 
               Prime coats do not include dust palliatives of
               tack coats.

          6.   "Road oils" shall be synonymous with slow cure
               asphalts.

          7.   "Tack coat" means any application of asphalt
               applied to an existing surface to provide a bond
               between new surfacing and existing surface to
               eliminate slippage planes where the new and
               existing surfaces meet.