IOWA LAUNCHES OVERLAY PROGRAM FOR 10-YEAR-OLD RIGID INTERSTATE

AN OVERLAY PROGRAM LAUNCHED BY THE IOWA HIGHWAY COMMISSION INVOLVES RESURFACING 75 MILES OF INTERSTATE HIGHWAYS WITHIN THE STATE. SIXTY MILES OF THE 75 MILES OF HIGHWAY ARE PORTLAND CEMENT. PATCHING AND CRACK-SEALING OPERATIONS WERE FIRST CONDUCTED WHERE DAMAGE WAS EXCESSIVE. THE CONTRACTOR REPLACED A TOTAL OF 200 SQUARE YARDS OF DAMAGED OR DETERIORATED PORTLAND CEMENT TO THE FULL DEPTH OF THE 10-INCH REINFORCED SLAB, AND REPLACED IT WITH NEW SLABS. WHERE DAMAGE HAD BEEN LESS SEVERE, THE PAVEMENT WAS LEVELLED AND STRENGTHENED WITH HOT-MIX ASPHALT, USING A CONVENTIONAL ASPHALT FINISHER EQUIPPED WITH ELECTRONIC SCREED CONTROLS. THIS MEANS HEAVY VOLUMES OF TOURIST TRAFFIC ARE APPARENTLY BEING CHANNELED THROUGH A COMPLICATED SYSTEM OF SAFETY SIGNS, CONES, AND FLAGMEN AS PAVING CREWS LAY A COMPLETELY NEW HOT-MIX ASPHALT SURFACE. TWO BATCH PLANTS WERE SET UP TO FEED FOUR PAVING CREWS. MORE THAN 6,000 VEHICLES PASS THROUGH THE CONSTRUCTION SITE EVERY DAY. TRAFFIC WAS SLOWED TO A SAFE SPEED BY INTERMITTENT BARRIERS BEFORE THEY REACHED THE ACTUAL WORK AREA. A PAINT-STRIPER PUT SOLID SHOULDER STRIPES AND INTERMITTENT DASHED CENTER LINES ON STILL-HOT ASPHALT. STRIPING WAS DONE BY THE HIGHWAY COMMISSION WORK FORCES, RATHER THAN THE CONTRACTOR. BEFORE THE BINDER COURSE OF 2-1/4 INCHES (COMPACTED) WAS SCHEDULED TO BE PLACED, THE OLD PAVEMENT SURFACE WAS TACKED WITH RC-7 AT A RATE OF .05 GALLONS PER SQUARE YARD, WITH A SAND TRUCK FOLLOWING THE DISTRIBUTOR TO BLOT UP EXTRA TACK AND PROTECT TRAFFIC MAINTENANCE. A 6-FOOT SCREED EXTENSION WAS PUT ON THE PAVER AND COVERED A 40-FOOT WIDTH IN THREE PASSES OF 18, 12, AND 10 FEET RESPECTIVELY. A 40-FOOT SKI FED SIGNALS TO THE ELECTRONIC SCREED CONTROL, USING THE EXISTING PAVEMENT FOR A REFERENCE, WHILE THE PAVER FOLLOWING ALONG IN THE ADJACENT LANE USED THE NEWLY-LAID MAT TO CONTROL THE LAYDOWN AND INSURE A PERFECT JOINT MATCH. TWO STEEL-WHEEL TANDEM ROLLERS OF 8 TO 12 TONS IN WEIGHT HANDLED BREAK-DOWN AND FINISH ROLLING, WHILE A RUBBER-TIRED ROLLER WITH 80 POUNDS CONTACT PRESSURE PROVIDED THE INTERMEDIATE COMPRESSION. COMMISSION ENGINEERS SPECIFIED A SPECIAL DOLOMITE AGGREGATE IN THE SURFACE MIX TO COMBAT ANY PROBLEM WITH SKIDDING. PERFORMANCE OF THE FULL-DEPTH ASPHALT INTERSTATE HIGHWAY PAVEMENT HAS EXHIBITED EXCELLENT PERFORMANCE BOTH FROM MAINTENANCE AND ROUTING QUALITY ASPECTS.

• Supplemental Notes:
  • pp 1-4, 6 PHOT
• Publication Date: 1969-6

Media Info

• Serial:
  • Paving Forum /Napa/

Subject/Index Terms

• TRT Terms: Aggregates; Asphalt; Bituminous materials; Dolomite; Electronic control; Hot mix asphalt; Mixing plants; Overlays (Pavements); Patching; Pavement cracking; Portland cement concrete; Resurfacing; Rigid pavements; Screeds; Sealing (Technology); Skid resistance; Surface treating; Tack coats; Tandem rollers; Work zone traffic control
• Identifier Terms: Interstate Highway System
• Old TRIS Terms: Bituminous mixing plants; Bituminous surfacing; Paving plant /travel type/; Rubber tired rollers; Sealing
• Subject Areas: Geotechnology; Highways; Maintenance and Preservation;

Filing Info

• Accession Number: 00218519
• Record Type: Publication
• Files: TRIS
• Created Date: Sep 29 1994 12:00AM