01021022

Component

https://doi.org/10.3141/1967-01

http://scholar.google.com...dman&publication_year=2006

The City of Ottawa, Canada, uses a Dynaflect to monitor the change in pavement strength during the spring thaw at 11 test sites selected to represent its arterial road network. As the average deflection of the sites approaches a threshold value, load restrictions are publicized by signage and advertisements in local newspapers. The restrictions remain in effect until deflections decrease below the threshold value. Local police equipped with portable weigh scales enforce the restrictions. The goal is to allow for the shortest possible restriction period and still ensure that the road infrastructure is protected. However, the decision to implement load restrictions is traditionally made too late, because prediction of thaw progression between weekly deflection testing is difficult. The city’s pavements are occasionally subjected to full-load hauling during the initial and most critical portion of the thaw period. To predict the onset and progression of the spring thaw better, the thaw index (TI) was used in addition to deflection testing. The TI (as calibrated separately by the Minnesota Department of Transportation and Manitoba Transportation and Government Services, Canada) was analyzed to determine whether it would predict the same implementation date as did deflection data. Results suggested that calibration factors provided by either agency are sufficiently accurate in the Ottawa environment but the Manitoba calibration is slightly more precise. Future investigation will involve use of surface curvature index, as well as direct temperature measurements from the city’s Road Weather Information Systems.

01037970

English

pp 3-9

2006

Transportation Research Record: Journal of the Transportation Research Board

0309099765

Print

Figures (5) ; References (16) ; Tables (2)

Accuracy; Arterial highways; Calibration; Deflection tests; Dynaflect; Forecasting; Implementation; Law enforcement; Load limits; Loads; Pavement performance; Police; Portable equipment; Spring; Strength of materials; Thaw; Weigh in motion scales

Minnesota Department of Transportation

Thaw index; Threshold values

Ottawa (Canada)

Design; Geotechnology; Highways; Pavements; Research; Security and Emergencies; I22: Design of Pavements, Railways and Guideways; I23: Properties of Road Surfaces

PRP, TRIS, TRB, ATRI

Mar 3 2006 10:19AM

• Asphalt Multi-Integrated Rollers and Steel Drum Compactors: Evaluating Effect of Compaction on Permeability of Asphalt Pavements
• Comparative Design Case Studies of Pavement Performance on Expansive Soils
• Design Model for Roughness and Serviceability of Pavements on Expansive Soils
• Duration of Spring Thaw Recovery for Aggregate-Surfaced Roads
• Effectiveness of Open-Graded Base Layer on Subgrade Moisture Regime and Overall Pavement Performance
• Estimating Thermal Conductivity of Pavement Granular Materials and Subgrade Soils
• Estimation of Expected Moisture Contents for Pavements by Environmental and Soil Characteristics
• Evaluation of Resilient Modulus Model Parameters for Mechanistic–Empirical Pavement Design
• Field Monitoring of Moisture Variations Under Flexible Pavement
• Hauling with Full Axle Weights and Reduced Tire Pressures on Weight-Restricted Roads in British Columbia
• Investigations of Environmental and Traffic Impacts on "Mechanistic-Empirical Pavement Design Guide" Predictions
• Laboratory Evaluation of Untreated and Treated Pavement Base Materials: Repeated Load Permanent Deformation Test
• Resilient Modulus Estimation System for Fine-Grained Soils
• Safety and Cost-Effectiveness of Approach Guardrail for Bridges on Low-Volume Roads
• Safety Effectiveness of Stop Control at Ultralow-Volume Unpaved Intersections
• Two-Dimensional Moisture Flow–Soil Deformation Model for Application to Pavement Design