FIVE YEARS OF DEVELOPMENT OF EMULSIFIED ASPHALTS FOR PAVEMENTS

THE USE OF CATIONIC EMULSIONS, INTRODUCED INTO BRAZIL IN 1962, HAS DEVELOPED RAPIDLY. NATIONAL PRODUCTION WAS 145,000 LONG TONS IN 1969 OUT OF A TOTAL OF 150,000 TONS, INCLUDING THE ANIONIC. THREE TOPICS ARE TREATED IN THE PRESENT REPORT; RESEARCH CATEGORIES, SPECIFICATIONS, AND QUALITY CONTROL. IMPORTANT TECHNOLOGICAL ADVANCES ACHIEVED IN THE LAST FIVE YEARS ARE AS FOLLOWS: (1) PENETRATING EMULSIONS - A NEW TYPE OF EMULSION WAS INTRODUCED TO THE MARKET REPLACING THE TWO OLD TYPES RRIK AND RR2K. THIS NEW EMULSION IS USED AT AIR TEMPERATURE AND HAS A HIGH-SPEED BREAKING POINT, (2) PREMIXED EMULSIONS OF MEDIUM BREAKING POINT - FOR A YEAR AND A HLAF URBAN PLANNING & SANITARY ENGINEERING SUPERINTENDENCE (SURSAN) HAS BEEN USING A NEW TYPE OF EMULSION OF MEDIUM BREAKING POINT WITH HIGH-SPEED CURING PERMITTING THE USE OF CONTINUOUSLY GRADED AGGREGATES FOR THE PAVING OF SURBAN STREETS OF RIO DE JANEIRO. THE AGGREGATE HAS 30-35% MATERIAL LESS THAN 2MM, PERMITTING A COMPACTNESS OF 91-96% TO BE OBTAINED. THIS NEW EMULSION IS MADE WITH A SOLVENT TWICE AS VOLATILE AS THAT OF CUT-BACK RC2, (3) PREMIXED EMULSIONS OF SLOW BREAKING POINT - CATIONIC EMULSIONS FOR ASPHALTIC CONCRETE AND BASE COURSES WITH A FILLER CONTENT OF 5 -15% HAVE BEEN DEVELOPED. ADVANCES IN THE SPECIFICATIONS OF EMULSIONS WILL REQUIRE THAT THE NEW CLASSIFICATION OF THE BRAZILIAN OIL INSTITUTE BE ADOPTED AND THE OLD ASTM CLASSIFICATION ABANDONED. IT IS RECOMMENDED THAT BEFORE STARTING A LARGE-SCALE WORK, EXPERIMENTAL SECTIONS BE USED TO REVEAL, AMONG THE VARIOUS EMULSIONS APPLIED, DIFFERENCES WHICH DO NOT APPEAR IN LABORATORY TESTS. CONSEQUENTLY, IT IS RECOMMENDED, IN ORDER TO EVALUATE CONTRACTOR BIDS, TO INTRODUCE A COEFFICIENT OF QUALITY WHICH WILL HAVE TO BE COMPUTED AT THE SAME TIME AS THE PRICE, BECAUSE FREQUENTLY THE BEST PRICE BECOMES THE MOST EXPENSIVE FOR PUBLIC AGENCIES. /RRI/

  • Corporate Authors:

    Road Research Institute /Brazil

    ,    
  • Authors:
    • Vogt, J C
  • Publication Date: 1970

Subject/Index Terms

Filing Info

  • Accession Number: 00211599
  • Record Type: Publication
  • Source Agency: Road Research Institute /Brazil
  • Files: TRIS
  • Created Date: May 16 1971 12:00AM