Smoothness Specifications for Pavements Final Report (1997) / Chapter Skim
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Chapter 2. Agency Survey Results
Chapter 2. Agency Survey Results
Pages 7-28
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From page 7... ...
From these lists, IS asphalt paving contractors and 18 concrete paving contractors located throughout the country were identified for participation in the June, 1994 survey. As with the State survey, research team members preceded the contractor questionnaire with a telephone call so Cat the appropriate individuals within each company couict be identified.
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From page 8... ...
For AC overlays, the number of agencies using a ride quality specification dropped slightly to 19 for AC overlays on PCC, and to 26 for AC overlays on AC. An additional 20 agencies indicated using straightedges or str~nglines as part of a bump specification for both pavement types.
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From page 9... ...
Five other respondents indicated using straightedges or stringlines as part of a bump specification. The remaining 5 agencies did not indicate the use of PCC smoothness specifications largely, it is believed, because they do not construct PCC pavements.
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From page 10... ...
Minimum roughness levels prior to incurring incentive payments 10 9 8 7 ~ CO ._ ~ 6 q) so o z 4 1 o _ ~NewAC · New PCC Notes KS ~40j~mi on AC and 50 in/ml ~ P~C~Q uses zero blanking band.
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From page 11... ...
The pie charts in figures 6 and 7 illustrate the breakdowns in equipment type used for measuring initial smoothness of asphalt surfaced pavements and concrete pavements, respectively. It should be noted that these distributions include all of the types of equipment specified by each agency, be they two or more profiling devices or a profiling device supplemented by a straightedge 0.5= 6% 0.4 31% Note: Corresponding to 25-ft Base 0.3 in 63% Figure 5.
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From page 12... ...
KJ Law 690 DNC Rolling 3% LISA Straightedge 1% . a, Equipment Legend KJ Law 690 DNC - Noncontact Inertial Profilometer LISA - Lightweight Noncontact Inertial Profilometer California - California Profilograph Ames - Ames Profilograph Rainhart- Rainhart Profilograph Mays (vehicle)
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From page 13... ...
As seen In table I, SHAs base the selection of smoothness specifications and ~ncentive/disincentive payment schedules on various items. For each of Tree main pavement types, at least one-third of the agencies Indicated basing their specifications and payment schedules on methocis other than research, engineering judgment, and AASHTO or other specifications.
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From page 14... ...
Engineering judgment 9 Other agency specifications 4 4 AASHTO guide specification 3 5 Other 18 20 Total number of agencies responding 43 Basis on which incentive/disincentive payment amounts are determined Fixed amount, $/yd2 1 7 | 7 Portion of the unit bid | 14 | 24 Other _ l 5 | 4 Total number of agencies responding 26 35 Basis for selection of relationship between incentive/disincentive payment and smoothness Engineering judgment 4 AASHTO guide specification 1 3 Other agency specifications 3 4 ~ Research and analysis 6 3 . Other 10 15 Total number of agencies responding l 24 ~32 AC Overlay 9 10 3 2 18 42 6 13 6 25 5 lo 1 2 5 10 22 1 yd2 = 0.84 m2 14
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From page 15... ...
Breakdown of responses concerning the need for separate specifications. Specified Field Procedures For each of the three main pavement types, smoothness progress testing is largely performed by the paving contractor.
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From page 16... ...
~ New PCC or j l Response | New AC | PCC Overlay I AC Overlay I Party responsible for smoothness progress testing | Contractor | 28 | 32 l State 12 10 Over l Totalnumber of agencies responding 1 43 1 46 l Party responsible for smoothness acceptance testing Contractor | 5 | 9 l State 28 Other 7 Total number of agencies responding 1 44 | 44 l Extent of smoothness measurement sampling Entire paving leng* l 29 38 Random samples Total number of agencies responding | 38 | 44 l Unit length of paving section individually evaluated for smoothness 528 it (0.1 mi)
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From page 17... ...
blanking band for evaluation of profiIograph traces. Table 3 shows that, for each of the three main pavement types, approximately 86 percent of the respondents indicate use of this blanking band limit.
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From page 18... ...
Satisfaction With Current Specifications When questioned about the adequacy of their current smoothness specifications, most States felt Weir specifications were either adequate or in need of slight unprovement. Of 45 responding agencies, 24 indicated Weir current specifications were adequate, 16 indicated slight improvements should be made, and 5 indicated their specifications should be replaced.
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From page 19... ...
There also appears to be problems In correlating the Rainhart profilograph with other devices. In fact, not only is the Rainhart profilograph perceived to be unsatisfactory at correlating with other devices, but its data collection rate and data reduction effort are largely judged unsatisfactory, much like the Ames profilograph.
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From page 20... ...
Statistical results of Ames profilograph ratings (] = satisfactory, 5 = unsatisfactory)
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From page 21... ...
Statistical results of Mays Meter ratings (1 = satisfactory, 5 = unsatisfactory)
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From page 22... ...
Other areas of dissatisfaction largely noted by the SHAs include durability, set-up effort, and the level of expertise required. Effects of Specifications Many responses were provided to various questions regarding the effects of smoothness specifications and ~ncentive/disincentive payments.
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From page 23... ...
New PCC or Response ~New AC | PCC Overlay I AC Overlay : result of current smoothness specification on initial pavement smoothness Records show noticeable smoothness increase 8 17 7 || 'erceived smoothnessincrease 1 13 | 13 | 133 l I Joincreased smoothness 1 8 1 7 T 7g l I Jot sure,too early to tell 1 6 1 3 T 5g l I Jo specification now 1 6 1 1 T 8g l I rotalnumberof agencies responding 1 41 1 41 T 40j || result of current smoothness specification on material/construction quality control j1 l | records show better quality | 2 | 4 T 11 Perceived quality increase | 16 | 20 | 15 11 l Jo increased quality ~8 1 6 T 7 11 l Cot sure; too early to tell 1 6 1 7 T 5 ill l Jo specification currently | 7 | 2 | 9 g l Cotalnumber of agencies responding | 39 | 39 | 38 al I | (esuIt of incentives/disincentives on initial pavement smoothness 21 l records show significantly smoother | 12 | 19 | 11 1 pavements _ _ do difference in pavement smoothness T 2 1 2 1 0 All i | dot sure; too early to tell | 9 | 11 | 8 : Jo incentives/disincentives in specification ~9 ~5 ~12 . ~ 'otal number of agencies responding ~32 ~37 ~31 i | (esuit of incentives/disincentives on overall cost to S tale j1 ;igruficantly higher overall payments T 2 ~6 ~2 || I iignificantlyloweroverallpayments T 2 1 1 ~1 11 I dot sure;too early to tell T 17 ~23 ~16 11 .
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From page 24... ...
| Response | New AC | New PCC/PCC Overlay | AC Overlay || Retention of initial pavement roughness data Pavements 1 to 3 years old 1 13 1 10 l Pavements 4 to 9 years old 8 14 Pavements more Man 9 years old | 6 | 9 l _ Total number of agencies responding 27 33 Retention of extended pavement roughness data Pavements 1 to 3 years old 4 2 Pavements 4 to 9 years old 9 9 . Pavements more Wan 9 years old 9 Total number of agencies responding 21 20 0 7 l 7 24 3 0 8 2 30, cn ~ 25 20 ._ 1 o co ~ 10 o 0 5 Ad o @' Initial Roughness Extended Roughness 14 8 25 20 1 to 3 years old 4 to 9 years old >= 9 years old All ages Pavement Age Category Figure 15.
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From page 25... ...
Of the 10 concrete paving respondents, ~ noted using the California profilograph, 3 noted using the Mays Meter, and 2 noted using the Ames profilograph. Straightedges were quite common among both types of paving contractors.
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From page 26... ...
. Moreover, each of the 16 responding contractors agreed that obtaining smoother pavements requires attention to other aspects of production, hereby improving the overall quality of the highway.
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From page 27... ...
To improve pavement smoothness, the responding contractors noted making several operational changes In the last 5 years. Most of these changes were made In the areas of paving equipment and procedures, subgrade quality control, paving mixture quality control, and roughness measuring procedures.
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From page 28... ...
Summary This chapter has presented a brief discussion of the results from a questionnaire survey on current roughness-measur~ng practices. Surveys were conducted of both SHAs and major highway paving contractors in March and June, 1994, respectively.
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