ASTM Definition of Roughness

Transcription

1 Pavement Smoothness

2 ASTM Definition of Roughness The deviations of a pavement surface from a true planar surface with characteristic dimensions that affect vehicle dynamics

3 Pavement Smoothness is a lack of roughness

4 National Customer Survey Pavement Condition (smoothness) 36% Safety 22% Traffic Flow 16% Visual Appeal 11% Bridge Condition 6% Maintenance Response Time 6% Travel Amenities 3%

5 NHI Model (1993 AASHTO Pave.) PSR= Constant x e ( *IRI) PSR IRI

6 Purposes for Smoothness Measurements Maintain construction quality Locating abnormal changes in the highway subsurface problems, drainage,construction deficiencies Allocation of road maintenance resources Pavement serviceability performance and design

7 Smoothness Measurements History

8 Methods Rolling Straightedge Ride Number (AASHO Road Test) BPR Roughometers Mays Ride Meter California Type Profiler (PI), La Specs since early eighties Inertial type Profilers (RN,PI, IRI)

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10 California Type Profilograph

11 Setting up Calibration Site w/ Walking Profiler

12 ICC laser profiler measures pavement profile (IRI), rutting, and PCC joint faulting at normal highway speeds.

13 Current LA DOTD Pay Adjustment Payment Adjustment (%) Current Specifications Based on PI 2 Multi-lift new construction and overlays more than two lifts Single-lift construction over cold planed surfaces and two lift overlays Single-lift overlays over existing surfaces or Remove # > 6.0 # > 10 # > 15

14 Internatinal Roughness Index (IRI) Linear Exponential Polynomial Hyperbolic Profile Index, PI 2

15 350 International Roughness Index, IRI Field data Linear function Polynomial function Power function Exponential function Profile Index with 0.2 in Blanking Bandwidth, PI 2

16 200 International Roughness Index, IRI µ (IRI) + σ (IRI) Linear function: IRI = (PI 2 ) (R 2 = 0.94) Polynomial function: IRI = (PI 2 ) (PI 2 ) 2 (R 2 = 0.96) Exponential function: IRI = e (PI 2 ) (R 2 = 0.96) Profile Index with 0.2 in Blanking Bandwidth, PI 2

17 Existing Smoothness Specifications Profile Index 0.2 Blanking Band

18 Deficiencies with Current PI System (Manual) Labor Intensive, Slow, Safety? Blanking Band Filtering out Roughness PI does not represent the ride of the Roadway

19 Analysis of Variance Well-defined relationship between IRI and PI values of < 20 For PI values > 20, high degree of variability

20 AMES LISA Lightweight Inertial Profiler Lightweight profilers measure pavement profile (IRI), Profile index, (PI), rutting, and PCC joint faulting at mph.

21 Surface Tolerance Requirements Inertial profilers approved by Materials Engineer Annual certification and site calibration Measurement of both wheel paths Average every 0.05 mile intervals Individual wearing course wheel path readings <89 for A&B, <110 for C Binder Course <110 (<105 for category A)

22 Requirements (Cont) diamond grind wearing course to meet specs Binder course corrected (optional methods) to meet specs Contractor Profile may be used for acceptance

23 %of Unit Price Percent of Contract Unit Price/in/mile/sublot 1 103% 100% 90% 80% 50% or Remove Cat. A Interstate and multi-lifts <55 < NA >75 Cat. B 2-Lift Overlay <55 < NA >89 Cat. C Single-Lift Overlay <55 < >110 Incentive Pay, < 45; Final Completion, Average of All Travel Lanes (with no lot less than 100% pay); +5% of the value of the wearing course (plan quantities)

24 1.00 EBLA28.P01 - B (24.000) - Section 1 of 1 - Seg 1 of 1 - PI 2: 0.00 (in/mi) IRI = 97 in./mile Track 2 (in) 0.00 PI = 0.0 in./mile (ft) Page 1 Old Spec (PI) vs. New Spec (IRI)

25 SBO.P01 - B (24.000) - Section 1 of 1 - Seg 64 of PI 1: (in/mi) PI 2: (in/mi) Track 1 (in) IRI = 195 In. / Mile 1.00 Track 2 (in) 0.00 IRI = 100 In. / Mile (ft) Page Project IRI = 53 In. / Mile Sublot IRI = 60 In. / Mile Example of Louisiana Bump Specification

26 La Proposed Specs, Flexible Pavements Percent of Contract Unit Price 100% 95% 90% 80% 50% or Remove Category A PI IRI 3.0 < NA NA NA NA >6.0 >65 Category B PI IRI < NA NA NA >10 >89 Category C PI IRI < NA NA NA >15 >110 Incentive 105 % of the value of the binder and the

27 Final Draft Percent of Contract Unit Price/Lot 1 Percent of Contract Unit Price (by Sublot) 100% 90% 80% 50% 2 or Remove Category A (in/mile) Multi-Lift New < NA >75 Construction and Overlays of More than two Lifts Category B (in/mile) One or Two Lift < NA >89 Overlay Construction Over Cold Planed Surfaces and Two- Lift Overlays Category C (in/mile) Single-Lift Overlays < >110 Over Existing Surfaces Shoulders <110 NA NA >110 Pay 70% or Remove Incentive Pay, Final Completion, Average < 45 of All Travel Lanes +10% of the value of the wearing course (plan quantities) (with no lot less than 100% pay) (1) or Portion of lot placed on the project. (2) At the option of the engineer.

28 Development of IRI Specifications for PCCP LTRC Pavement Group

29 Methodology Collection of Profile Data on Selected PCCP jobs using LTRC ICC s High Speed Profiler Developing PI and IRI data from the selected Sites Using Linear Regression to Establish IRI values based on the Existing PI specifications ( similar to what was done for flexible pavements)

30 Data Sample IRI-PI COMPARISON ON NEW JCP, 0.05 MILE SEGMENTS NORTHLINE ROAD (ALF RD) EB-IWP EB-OWP WB-IWP WB-OWP IRI PI IRI PI IRI PI IRI PI

31 IRI & PI (each 0.05 mi. seg) IRI & PI IRI (in/mile) y = x PI ( in/mile)

32 Initial JCP IRI; In/mile Freq. (0.05 mi. seg.) % 24% 20% 12% 5% 1% 0% IRI

33 PCC Pavements Category I > 45 mph 100 Payment ( Percent of Contract Unit Price/lot) % or remove and replace P I I R I Correct or Remove > 8.0 >85 Cat. II, Urban Areas < 45 mph P I 12 I R I >14.0 >99 Cat. III non-continuous P I >26 operations < 45mph I R I >129

34 IRI Calibration Requirements Five runs over each of two test locations Report mean and standard deviation The mean shall be within 5% of DOTD reference value for each test location. The standard deviation must be less than 3% of the mean IRI value in inches per mile DOTD to affix tag to certified unit with necessary computer settings

35 The Bottom Line is a Straight Line Every phase of construction is a new opportunity to achieve a smoother road Roadway maintenance will decline Our customers get what they asked for, a smooth ride.

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