As part of task 1 of strategic highway research program project c-103, "concrete bridge protection and rehabilitation: chemical and physical treatments", state and provincial highway agencies in the united states and canada were surveyed in early 1989 by mailed questionnaire on the status and service life of protective and rehabilitative treatments applied to concrete components of bridges in their jurisdictions. responses were received from 47 states and 9 provinces.respondents indicated that patching with rigid mortar or concrete (portland cement, quick-set, or polymer) is more widely accepted as astandard practice than any other deck treatment category (71.4% of agencies). some treatments were judged by more agencies to be experimental rather than standard and were associated with generally loweracceptance frequencies. with the exception of cathodic protection, treatments for substructure and superstructure concrete were judged to be far less experimental than those for decks, and the standard acceptance frequencies more uniform. opinions on the service life of treatments were generally widely scattered. median responses for deck treatments varied from 1 year for asphalt concrete patching to greater than 20 years for micro-silica overlays; and for nondeck treatments from 5 to 10 years for sealers to 20 years for cathodic protection. questionnaire responses have been used to focus the study of service life expectancy in task 1 on those treatments considered to bein the mainstream of current practice. this paper appears in transportation research record no. 1304, highway maintenance operations and research 1991.
Samenvatting