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From page 32... ... NCHRP Project 14-30 32 CHAPTER 3 Field Spot Painting Work 3.1 Background To address the fourth element of the KTC research, candidate bridges were sought for field spot painting. This work employed processes presented in the guidance document including coating assessments, the SSPC-SP 3 "Power Tool Cleaning" specification (using vacuum shrouded tools to reduce airborne particulate exposure) Read the entire page →
From page 33... ... NCHRP Project 14-30 33 3.2.1 KY 9002 Bluegrass Parkway Bridge over US 60 The Bluegrass Parkway Bridge was constructed in the mid-1960s. The bridge was originally painted with the basic lead silico-chromate alkyd primer and leafing and non-leafing aluminum alkyd intermediate and finish (top) Read the entire page →
From page 34... ... NCHRP Project 14-30 34 3.2.2 KY 922 Twin Bridges over KY 4 The KY 922 twin overpass bridges were continuous multi-span bridges with joints over the abutments. The bridges were built in the 1960s. Read the entire page →
From page 35... ... NCHRP Project 14-30 35 SSPC Technology Guide 15: "Field Methods for Extraction and Analysis of Soluble Salts on Steel and Other Nonporous Substrates," using the patch and sleeve methods - Methods 4.2.2 and 5.2.5 respectively) Read the entire page →
From page 36... ... NCHRP Project 14-30 36 Table 7. Coating Assessment for Beams 1, 2 & 3 Over Pier 1 (West) Read the entire page →
From page 37... ... NCHRP Project 14-30 37 determined that in most of the spot painting areas, the residual soluble salt levels would be sufficiently low to mirror those used in the KTC laboratory tests. The XRF testing revealed that lead was the only heavy metal present in the three bridges. Read the entire page →
From page 38... ... NCHRP Project 14-30 38 3.3.2 KTC Training Relative to the Field Work The KTC technicians assigned to the spot painting tests had the following training: OSHA 10Hour Construction Training, lead awareness and fall protection training, SSPC PCI Level I coating inspector (one technician) and man-lift training. Read the entire page →
From page 39... ... NCHRP Project 14-30 39 including any solvents were disposed of by KTC as part of its routine in-house painting procedures. KTC researchers determined that testing of the Bluegrass Parkway Bridge at the West Pier 1 required the use of a man-lift. Read the entire page →
From page 40... ... NCHRP Project 14-30 40 anticipated. The progress of the power tool cleaning was rapid in these areas as there was little surface rust to be cleaned and the existing coating readily came off in most areas. Read the entire page →
From page 41... ... NCHRP Project 14-30 41 An electronic digital dew point meter was used to measure air temperature, surface temperature of the steel, the relative humidity and the dew point (Figure 30) Read the entire page →
From page 42... ... NCHRP Project 14-30 42 Measurements were taken to determine the widths of the repair area to be covered with each application of the tapes. The tapes were cut into strips and placed over the repair area lapping the existing coating at the repair boundary by about two inches. Read the entire page →
From page 43... ... NCHRP Project 14-30 43 In addition to the spot coating repairs performed under the deck, a spot repair was made to a badly peeling area on the external face on a fascia girder near the east abutment (about 20 ft2) Read the entire page →
From page 44... ... NCHRP Project 14-30 44 During the field work, one KTC technician was fitted with an air monitor to determine his respirable lead exposure during an 8-hour period when conducting surface preparation using needle guns and sanders and grinders. He was monitored working on the three bridges while wearing a half-face respirator by a certified industrial hygienist who routinely performed similar tests for paint contractors working in Kentucky. Read the entire page →
From page 45... ... NCHRP Project 14-30 45 Bridge, had been applied at an excessive paint thickness (the polyurethane top coat) Read the entire page →
From page 46... ... NCHRP Project 14-30 46 In Area 2 of the Bluegrass Parkway Bridge, alkyd 2-coat system (Coating 1) generally was performing well with one small rust spot at the bottom of the test patch where there had been significant corrosion pitting prior to the spot painting (Figure 41) Read the entire page →
From page 47... ... NCHRP Project 14-30 47 cleaning problems in tight areas combined with insufficient thickness of the grease coating in the rusted areas. The grease was tacky and had picked up a significant amount of airborne debris. Read the entire page →
From page 48... ... NCHRP Project 14-30 48 Bluegrass Parkway Bridge required the use of a ladder in assess the existing coatings in Area 2 of the bridge steel over Pier 1. The abutment locations on the bridges were accessed at ground level. Read the entire page →
From page 49... ... NCHRP Project 14-30 49 Table 10. KTC Ratings of Power Tools Tools \ Rating Category Set Up Ease of Use Duty Cycle Effectiveness Comments Needle Gun (Electric) Read the entire page →
From page 50... ... NCHRP Project 14-30 50 performing work had the appropriate worker safety training and fitting of respirators. The necessary equipment and supplies (as previously noted) Read the entire page →

From page 32...

... NCHRP Project 14-30 32 CHAPTER 3 Field Spot Painting Work 3.1 Background To address the fourth element of the KTC research, candidate bridges were sought for field spot painting. This work employed processes presented in the guidance document including coating assessments, the SSPC-SP 3 "Power Tool Cleaning" specification (using vacuum shrouded tools to reduce airborne particulate exposure)