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OCR for page 42
42 spections may record condition data as indicators of ade- Casting joint quacy of work by the maintenance contractor. Delamination, spalling Defects in bridges are reported in terms of physical, func- tional, and economic conditions. Physical condition is reported Porous or bad quality concrete as a measurement of an appropriate physical quantity. The quan- tity and the method of its measurement are fitted to the type of Area of measurement damage, structural element, material, and other considerations (e.g., mode of action of element). Functional condition is re- Cracks ported on a 0 to 3 rating scale, with 3 being the worst condition (Table 72). Functional condition is related to the time until the Cracks > 0,2 mm, < 2,0 mm defect is expected to impair the service of the bridge. Economic condition is expressed as cost. Economic con- Cracks > 2,0 mm dition is computed as defect quantity times average unit cost Cracking for repair. This is not an estimate of actual project costs, because project scope may differ from defect quantity. Visibly corroding reinforcement However, greater values of economic condition correctly in- dicate more severe and more extensive defects. FIGURE 1 Norwegian graphic symbols for damage. United Kingdom During Principal inspections, defect severity is reported on a South Africa 1 to 5 scale, and defect extent on an "A" to "E" scale. These SANRAL records defects in bridge components with ratings condition ratings are used in Structures Management Infor- for Degree, Extent, Relevancy, and Urgency. This system mation System to generate the performance indicator for employs integer ratings in all four categories (Table 70). Rat- visual condition. ings range from 0 (no defect) to 4 (critical defect) (Table 71). ACCESS FOR INSPECTIONS-- Sweden FOREIGN AGENCIES The SRA collects ratings and other data on conditions of Foreign road agencies reported on the use of traffic lane clo- bridge components during General, Major, and Special sures, lifts or climbing for acceptance inspections, principal inspections. A Regular inspection may yield a report of dam- inspections, and special inspections; that is, at longer inspec- age that is followed up by a Special inspection. The condition tion intervals. These access methods are not used during rou- data, strictly, are from the Special inspection. Superficial in- tine inspections at shorter intervals (Tables 7375). TABLE 70 SOUTH AFRICA: DEFECT CATEGORIES Category Description D--Degree of defect Severity of defect E--Extent of defect Prevalence of defect within the bridge element R--Relevancy of defect Impact of the defect on structural integrity and/or user safety U--Urgency of defect Recommended time for repair TABLE 71 TABLE 72 SOUTH AFRICA: DEFECT RATING VALUES SWEDEN: CONDITION RATINGS Rating Degree Extent Relevancy Urgency Rating Physical Condition Functional Condition 0 None Monitor only 3 Repair needed now Service impaired now 1 Minor Local Minimum Routine 2 Repair within 3 years Service impaired within 3 years 2 Fair >Local Moderate <5 year 1 Repair within 10 years Service impaired within 10 years 3 Poor OCR for page 42
43 TABLE 73 USE OF LANE CLOSURES FOR INSPECTIONS--FOREIGN AGENCIES Country Inspection Type Lane Closures Denmark Routine, Principal Very rare Special Nearly always Finland General Rarely, except if inspection lift is used Basic, Special Often France Routine, Annual, IQOA No Detailed Yes Germany Superficial, Minor, No Major Yes, if needed Norway General No All other types Inspectors must be at arms length to component South Africa Principal Yes, if needed Acceptance Yes, to test water tightness of joints Other types Seldom used Sweden General, Major, Special If needed Routine, Superficial No United Acceptance, Special Yes, but structure may not be open at time of acceptance Kingdom inspection. For special inspection, closure may be used during installation of instruments for monitoring. All others No TABLE 74 USE OF LIFTS AND OTHER EQUIPMENT FOR INSPECTION ACCESS--FOREIGN AGENCIES Country Inspection Type Lifts, Other Equipment Denmark Special Nearly always uses lifts Principal, Special Might use boats Finland General Rarely General, Large bridge Often Basic, Special Often France Routine, Annual, IQOA No Detailed Yes, France has a special snooper for great arches and piers. Germany Superficial, Minor, No Major Yes Norway General No All other types Inspectors must be at arms length to component South Africa Principal If needed Other types Seldom used Sweden General, Major, Special If needed Routine, Superficial No United Kingdom Acceptance, Principal, Special Yes General No TABLE 75 USE OF CLIMBING, LADDERS, AND OTHER METHODS FOR BRIDGE INSPECTION-- FOREIGN AGENCIES Country Inspection Type Climbing Denmark Special Large structures and by special personnel only Finland All Climbing is not used. Access is by lifts, if necessary. Germany Superficial, minor No Major Yes, if needed Norway General No All other types Inspectors must be at arms length to component South Africa Principal If needed Other types Seldom used Sweden General, major, special If needed, and performed by trained personnel Routine, superficial No United Kingdom Special Yes, abseilers (rappelling)