PROTECTION FOR CONCRETE BRIDGE DECKS BY MEMBRANE WATERPROOFING

STANDARD PRACTICE IN MASSACHUSETTS IS TO USE A MEMBRANE WATERPROOFING ON ALL NEW CONSTRUCTION OF CONCRETE BRIDGE DECKS THAT ARE TO BE COVERED BY BITUMINOUS CONCRETE. RESTORATION OF CONCRETE BRIDGE DECKS THAT HAVE DETERIORATED TO THE POINT OF REQUIRING REPAIRS, INCLUDE MEMBRANE WATERPROOFING AS A PART OF THE RESTORATION PROJECT. BRIDGES BUILT PRIOR TO 1940 WITHOUT ADEQUATE DECK WATERPROOFING THAT HAVE A BITUMINOUS CONCRETE RIDING SURFACE OF VARIOUS THICKNESSES ARE PRESENTLY BEING RESTORED. THE 1958 DEPARTMENT SPECIFICATIONS CALL FOR MEMBRANE WATERPROOFING AND FOR 2-PLY COATED WOVEN-GLASS FABRIC PLACED BETWEEN 5 MOPPINGS OF A COAL TAR PITCH EMULSION. PROCEDURES AND COSTS ARE REVIEWED. THE EMULSION IS THOROUGHLY AGITATED IN ITS CONTAINER AND NO ADULTERANTS OF ANY NATURE WERE ADDED. WHERE MEMBRANE WATERPROOFING IS PLACED AT STEEL EXPANSION JOINTS, SCUPPERS, MANHOLES OR OTHER METAL PROJECTING THROUGH THE CONCRETE, THE MEMBRANE IS TURNED UP ABOUT 1 1/2 INCHES AND SEALED TO THE METAL. BLEEDERS, 2 INCHES IN DIAMETER, ARE INSTALLED AT THE CURB LINES, PRIOR TO THE PLACING OF THE MEMBRANE WATERPROOFING. THE WATERPROOFING IS PROTECTED THROUGHOUT ALL OPERATIONS OF PLACING THE BITUMINOUS-CONCRETE BASE COURSE. NO VEHICLES ARE PERMITTED ON THE BARE WATERPROOFING. THE FIRST COURSE OF BITUMINOUS CONCRETE MUST BE SPREAD BY HAND. PERFORMANCE OBSERVATIONS SHOW SATISFACTORY RESULTS FROM THIS METHOD OF WATERPROOFING. NO OTHER METHOD OR MATERIALS HAVE BEEN FOUND THAT WILL PRODUCE COMPARABLE RESULTS AT SUCH A REASONABLE COST.

Media Info

  • Media Type: Print
  • Pagination: pp 58-60
  • Monograph Title: Maintenance practices 1967
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00218438
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Jan 23 1994 12:00AM