High Molecular Weight Methacrylate Sealing of a Bridge Deck, HR-2031, 1988

(1988) High Molecular Weight Methacrylate Sealing of a Bridge Deck, HR-2031, 1988. Transportation, Department of

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Abstract

The Iowa Department of Transportation used a high molecular weight methacrylate (HMWM) resin to seal a 3,340 ft. x 64 ft. bridge deck in October 1986. The sealing was necessary to prevent deicing salt brine from entering a substantial number of transverse cracks that coincided with the epoxy coated top steel and unprotected bottom steel. HMWM resin is a three component product composed of a monomer, a cumene hydroperoxide initiator and a cobalt naphthenate promoter. The HMWM was applied with a dual spray bar system and flat-fan nozzles. Initiated monomer delivered through one spray bar was mixed in the air with promoted monomer from the other spray bar. The application rate averaged 0.956 gallons per 100 square feet for the tined textured driving lanes. Dry sand was broadcast on the surface at an average coverage of 0.58 lbs. per square yard to maintain friction. Coring showed that the HMWM resin penetrated the cracks more than two inches deep. Testing of the treated deck yielded Friction Numbers averaging 33 with a treaded tire compared to 36 prior to treatment. An inspection soon after treatment found five leaky cracks in one of the 15 spans. One inspection during a steady rain showed no leakage, but leakage from numerous cracks occurred during a subsequent rain. A second HMWM application was made on two spans. Leakage through the double application occurred during a rain. Neither the single or double application were successful in preventing leakage through the cracks.

Item Type: Departmental Report
Keywords: Bridge decks, Friction, Inspection, Leakage, Sealing (Technology), Transverse cracking
Subjects: Transportation
Transportation > Materials
Transportation > Bridges and tunnels
Transportation > Roads and highways
Transportation > Design and Construction
ID Code: 16753
Deposited By: Iowa DOT Library
Deposited On: 02 May 2014 11:38
Last Modified: 29 Jun 2015 15:17
URI: http://publications.iowa.gov/id/eprint/16753