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From page 19... ... Responses from the worldwide survey indicated that the residual application rates of emulsions typically vary from 0.02 to 0.08 gal/yd2, depending on the type of pavement surface. As pavement temperature increases, laboratory bond strength significantly decreases for all tack coat types and application rates. Read the entire page →
From page 20... ... The residual application rate of 0.155 gal/yd2 was Variables* Content Levels Pavement surface type Old HMA, New HMA, PCC, Milled HMA 4 Tack coat material SS-1h, SS-1, CRS-1, Trackless, PG 64-22 5 Residual application rate 0- (No-Tack) Read the entire page →
From page 21... ... Wet 0.031 gsy Wet 0.031 gsy Wet 0.031 gsy Wet 0.031 gsy Dry No Tack Dry 0.031 gsy Adjacent Area Dry 0.062 gsy Wet 0.062 gsy Adjacent Area Wet No Tack Dry No Tack Dry 0.031 gsy Adjacent Area Dry 0.062 gsy Wet 0.062 gsy Adjacent Area Wet No Tack 4.6 ft 4.6 ft 4.6 ft 50 ft 4.6 ft 4.6 ft 4.6 ft 35.1 ft 4.5 ft 4.5 ft 50 ft 4.6 ft 4.6 ft 35 ft Dry No Tack Dry 0.031 gsy 2 Adjacent Area Dry 0.062 gsy Wet 0.062 gsy Adjacent Area Wet No Tack Dry No Tack Dry 0.031 gsy Adjacent Area Dry 0.062 gsy Wet 0.062 gsy Adjacent Area Wet No Tack 24.9 ft 4.6 ft 4.6 ft Dry 0.155 gsy Wet 0.155 gsy Dry 0.155 gsy Wet 0.155 gsy Dry No Tack Dry 0.031 gsy Adjacent Area Dry 0.062 gsy Adjacent Area Dry 0.155 gsy Dry No Tack Dry 0.031 gsy Adjacent Area Dry 0.062 gsy Adjacent Area Dry 0.155 gsy Adjacent Area Adjacent Area Adjacent Area Adjacent Area Adjacent Area Adjacent Area Adjacent Area 4.6 ft Dry 0.155 gsy Wet 0.155 gsy Dry 0.155 gsy Wet 0.155 gsy Dry No Tack Dry 0.031 gsy Adjacent Area Dry 0.062 gsy Adjacent Area Dry 0.155 gsy Dry No Tack Dry 0.031 gsy Adjacent Area Dry 0.062 gsy Adjacent Area Dry 0.155 gsy Adjacent Area Adjacent Area Adjacent Area Adjacent Area 40 ft Lane 1 Lane 4 Lane 2 Lane 3 Lane 5 215 ft Adjacent Area Clean Dirt Clean Dirt Clean Dirt Clean Dirt Figure 11. Layout of test lanes in the field experiment. Read the entire page →
From page 22... ... Water Spraying Using a Hose (b) Tack Coat Application on Dusty Surface (d) Read the entire page →
From page 23... ... Figure 14. Spraying process plan for four lanes at the test site. Read the entire page →
From page 24... ... Table 5 presents the results of these measurements for the tack coat distribution conducted at the test site. For SS-1h with 100% coverage, trackless, and CRS-1, target application rates of 0.062- and 0.155- gal/yd2 were achieved with relatively low errors, although errors for trackless and SS-1h exceeded the 10% error limitation specified by ASTM 2995D. Read the entire page →
From page 26... ... 50% Coverage Surface Figure 19. Typical tack coat surface coverage on old HMA surface (0.155 gal/yd2 residual application rate) Read the entire page →
From page 27... ... After conditioning the sample for a minimum of 4 hours, the sample was ready for interface shear strength testing. 3.3 Experiment Plan I: Development of a Test Device to Evaluate the Quality of the Bond Strength of Tack Coat Spray Application in the Field The objective of Experiment I was to develop a consistent and reliable test method to evaluate the bonding characteristics of tack coat spray application in the field. Read the entire page →
From page 28... ... Three residual application rates were considered: 0.031, 0.062, and 0.155 gal/yd2. The experimental program was designed to evaluate performance of tack coats between two HMA layers, a new overlay on an existing pavement. Read the entire page →
From page 29... ... Illustrations of the test procedure for interface shear testing. Read the entire page →
From page 30... ... To assess the influence of sample preparation methods, laboratory-fabricated specimens were prepared using five tack coat materials -- SS-1h, trackless, locally-used trackless (AUT) , PG 64-22, and CRS-1 -- as tack coat was applied at four residual application rates -- 0 (No Tack) Read the entire page →
From page 31... ... High High SS-1 0.000 3 0.031 3 0.062 3 0.155 3 Table 9. Test matrix to evaluate effects of texture and permeability on SS-1 tack coat. Read the entire page →
From page 32... ... Once the application and curing of the tack coat was completed, the top half of the specimen was applied by placing the bottom half in the SGC mold and compacting the prescribed mixture on top of the tack coated bottom half. Four-inch-diameter specimens were then cored from the SGC-compacted samples, and the interface shear strength was measured at 25°C. Read the entire page →
From page 33... ... 33 Structure A Structure B Structure C Structure D Structure E Structure F Figure 23. Pavement structures simulated in the FE analysis. Read the entire page →
From page 34... ... , the motion between the surfaces is elastic and recoverable. However, if the applied shear stress exceeds the interface shear strength, the interface fails and the interface condition is converted to a simple friction model, defined by a friction coefficient (µ = 0.7) Read the entire page →

From page 19...

... Responses from the worldwide survey indicated that the residual application rates of emulsions typically vary from 0.02 to 0.08 gal/yd2, depending on the type of pavement surface. As pavement temperature increases, laboratory bond strength significantly decreases for all tack coat types and application rates.