A rapid expansion of the polyurethane spray elastomer is expected as a waterproofing for concrete bridge deck technology inJapan. The traditional bitumen waterproofing for concrete bridge deck in Japan has been used since Japanese governmenthad issued the guidance in 1978, but some papers report it loses the watertight capability within several years. Polyurethanewaterproofing for concrete deck has excellent quality stability for years and maintains long-time mechanical and chemicaldurability due to its elastic and thermo setting characteristics. This waterproofing system has been in the practical stage inJapan since 2003. The Japanese thinner asphalt concrete needs more attention to the bonding between asphalt concrete andwaterproofing layer. The difficulty of this bond between polyurethane membrane and asphalt concrete caused a few ofpavement troubles in the first stage. The polyurethane waterproofing system could provide excellent stability of pavement bydeveloping the perforated elastomer sheet for bonding. The wheel running machine, the rotating fatigue testing machine andthe random wheel tracking machine showed excellent shearing strength and shearing durability. The rutting of the pavementwas minimal, and it was presumed that there was a life-extending effectiveness of the pavement as a result. Thiswaterproofing was conducted at Yahagigawa Bridge in New Tomei Expressway and also adopted in the taxi way bridge inKansai International Airport where high shearing strength was demanded with passing of heavy jumbo jet aircraft.
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