The National Academies Press

Currently Skimming:

Pages 72-102

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.

From page 72... ... 72 A P P E N D I X C Tabulated State Survey Responses This section summarizes the responses to the survey as reported by the state and provincial agencies. Numbers in brackets or on Totals line in tables are the number of responses for each option [U.S. Read the entire page →
From page 73... ... Tabulated State Survey Responses 73 (continued on next page) Agency Yes/Unsure/No If yes, how are these policies or guidelines enacted? Read the entire page →
From page 74... ... 74 Impact of Asphalt Thickness on Pavement Quality IL 0.75 in. Read the entire page →
From page 75... ... Tabulated State Survey Responses 75 9.5-mm Mixes Agency Fine Dense-Graded Coarse Dense-Graded SMA Open-Graded Min Max Min Max Min Max Min Max AL 1.25 in. Read the entire page →
From page 76... ... 76 Impact of Asphalt Thickness on Pavement Quality 12.5-mm Mixes Agency Fine Dense-Graded Coarse Dense-Graded SMA Open-Graded Min Max Min Max Min Max Min Max AL 1.50 in. Read the entire page →
From page 77... ... Tabulated State Survey Responses 77 19.0-mm Mixes Agency Fine Dense-Graded Coarse Dense-Graded SMA Open-Graded Min Max Min Max Min Max Min Max AL 2.25 in. Read the entire page →
From page 78... ... 78 Impact of Asphalt Thickness on Pavement Quality 25.0-mm Mixes Agency Fine Dense-Graded Coarse Dense-Graded SMA Open-Graded Min Max Min Max Min Max Min Max AL 3.00 in. Read the entire page →
From page 79... ... Tabulated State Survey Responses 79 37.5-mm Mixes Agency Fine Dense-Graded Coarse Dense-Graded SMA Open-Graded Min Max Min Max Min Max Min Max AL None None None None None None None None AK AZ N/A N/A AR 4.0 in. Read the entire page →
From page 80... ... 80 Impact of Asphalt Thickness on Pavement Quality 3. Do you specify different maximum lift thicknesses depending on mixture size and/or type? Read the entire page →
From page 81... ... Tabulated State Survey Responses 81 IN – For the situation described below, where 19.0 mm is substituted for 25.0-mm base. We "unofficially" would allow the 19.0 intermediate to be laid up to 6 in. Read the entire page →
From page 82... ... 82 Impact of Asphalt Thickness on Pavement Quality TX – Not allowed in the specification, but area office may consider to accommodate speed of construction (i.e., intersection construction that would allow for thicker base HMA layers) Read the entire page →
From page 83... ... Tabulated State Survey Responses 83 MD – https://policymanual.mdot.maryland.gov/mediawiki/index.php? title=504_ASPHALT_PAVEMENT. Read the entire page →
From page 84... ... 84 Impact of Asphalt Thickness on Pavement Quality 6. Are target densities the same if compaction is limited to static mode? Read the entire page →
From page 85... ... Tabulated State Survey Responses 85 Agency Nuclear Density Gauge Non-Nuclear Density Gauge Cores Other SC • • • SD • • TN • • TX • UT • VT • • • • VA • • WA • WV WI • • WY • AB • BC • MB NB • ON • Totals 21+0 7+0 39+4 6+0 Comments: ID – We use cores to correlate the Nuclear Density Gauge during the Acceptance Test Strip. LA – Moving to nondestructive QA. Read the entire page →
From page 86... ... 86 Impact of Asphalt Thickness on Pavement Quality 7B. If cores are used, how does your agency determine the bulk specific gravity (Gmb) Read the entire page →
From page 87... ... Tabulated State Survey Responses 87 8A. Have you observed paving contractors having more difficulty in obtaining required field densities since implementing the Superpave mix design system? Read the entire page →
From page 88... ... 88 Impact of Asphalt Thickness on Pavement Quality Agency Yes, initially but less so now Yes, continuing to be difficult Yes, with certain mixes or applications No Unsure Have not implemented Superpave VT • VA • WA • WV WI • WY • AB • BC • MB NB • ON • Totals 16+0 2+0 4+1 11+2 6+0 3+1 Comment: VA – Wanted to say "NO," but changed density requirements, mix design parameters (gyration level, design AV, gradation, etc.) Read the entire page →
From page 89... ... Tabulated State Survey Responses 89 8B. If the situation has improved, what changed? Read the entire page →
From page 90... ... 90 Impact of Asphalt Thickness on Pavement Quality 9A. Has your agency changed recommended or required lift thicknesses since implementing the Superpave mix design system? Read the entire page →
From page 91... ... Tabulated State Survey Responses 91 9B. If yes, what was the reason for the change? Read the entire page →
From page 92... ... 92 Impact of Asphalt Thickness on Pavement Quality 10. Does your agency use these tests or technologies for asphalt materials/placement? Read the entire page →
From page 93... ... Tabulated State Survey Responses 93 Comments on Workability: NY – Warm Mix technology, TN – Allow WMA to be used. NB – Visual - checking, cracking, pushing, shoving. Read the entire page →
From page 94... ... 94 Impact of Asphalt Thickness on Pavement Quality 11A. Have you observed contractors having increased difficulty obtaining adequate density in mixtures with certain components or in certain applications? Read the entire page →
From page 95... ... Tabulated State Survey Responses 95 Agency RA P RA S PM B G TR Ce rt ai n Bi nd er G ra de s H ig hl y A ng ul ar A gg re ga te s Ce rt ai n A gg re ga te Ty pe s Th in L ift s A t l ow b as e or m ix te m pe ra tu re W he n pl ac in g ov er co nc re te O th er VT • • • • • VA • • WA • WV WI • • WY AB • • • • • BC • MB NB • • • ON • • • Totals 13+0 5+0 12+3 2+1 5+2 10+0 3+0 12+1 18+4 3+0 12+1 Comments on Binder Grades: CA – RHMA-G mixes that use asphalt rubber binder (wet process) are harder to place and compact. Read the entire page →
From page 96... ... 96 Impact of Asphalt Thickness on Pavement Quality 11B. If yes, have you adopted any strategies to address these issues? Read the entire page →
From page 97... ... Tabulated State Survey Responses 97 12. Does your agency allow the use of warm mix asphalt technologies at conventional temperatures as a compaction aid? Read the entire page →
From page 98... ... 98 Impact of Asphalt Thickness on Pavement Quality Agency Yes No Permissive spec or not monitored If yes, does the use of WMA as a compaction aid seem to improve the ability to get density? Always Frequently Sometimes Never WA • WV WI • • WY • AB • BC • • MB NB • • ON • Totals 32+2 0+0 10+2 2+0 11+0 13+2 0+0 Comments: ID – Contractors achieve density. Read the entire page →
From page 99... ... Tabulated State Survey Responses 99 13. Have you observed any asphalt pavement performance problems that are perceived to be related in whole or in part to inadequate compaction during construction? Read the entire page →
From page 100... ... 100 Impact of Asphalt Thickness on Pavement Quality Comments: CO – CDOT has not studied this issue. Read the entire page →
From page 101... ... Tabulated State Survey Responses 101 15. Do you see a need for additional research into any of the following? Read the entire page →
From page 102... ... 102 Impact of Asphalt Thickness on Pavement Quality Comments: DE – N/A. GA – New equipment like lightweight deflectometer. Read the entire page →

From page 72...

... 72 A P P E N D I X C Tabulated State Survey Responses This section summarizes the responses to the survey as reported by the state and provincial agencies. Numbers in brackets or on Totals line in tables are the number of responses for each option [U.S.