Optimum Time for Application of Slurry Seal to Asphalt Concrete - PowerPoint PPT Presentation

Optimum Time for Application of Slurry Seal to Asphalt Concrete Pavements UNR Pavement/Materials Engineering Cooperative Agreement University of Nevada Reno ( UNR) Western Regional Superpave Center

Problem Statement and Objective  The time of Slurry Seal (SS) application is left to the Project Engineer judgment and practice.  SS right after construction  SS after 1, 3, 5 etc. years of service  …  Objective: Evaluate the field performance & effectiveness of SS on asphalt pavements in Truckee Meadows Region 2 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Research Phases  Phase I:  Evaluate effectiveness & optimum time for single application of slurry seal  Phase II:  Evaluate effectiveness & optimum time for sequential application of slurry seal 3 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Phase I: Research Approach  Collect & evaluate performance data of asphalt pavements  without slurry seal  receiving single slurry seal at various times: 0, 1, 3, 5, 7, and 9.  Identify effectiveness & optimum time for SS application. 4 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Phase I: Evaluated Sections  Asphalt pavement sections were identified within the jurisdictions of: WCED, COR and COS. Initial Road T otal number Construction ADT Classification of sections Pavement Type  10,000 Arterial 36 New Construction Collector < 10,000 33 Residential < 6,000* 525  10,000 34 Arterial Overlay Collector < 10,000 226 Residential < 6,000* 1,848 * With a high percentage of trucks (> 4%) 5 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Phase I: Evaluated Sections (Cont’d)  Within each group (i.e. Road class), pavement sections were broken into three categories:  Do – Nothing: SS was not applied to the pavement  SS applied immediately after construction (referred to as 0)  SS applied at: 1, 3, 5, 7, and 9 years after construction  Performance was measured in terms of PCI. 6 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Performance Models for Newly Constructed Pavements without Slurry Seal 100 100 R² = 0.98 R² = 0.98 80 80 60 60 PCI PCI 40 40 20 20 PCI = -0.0058 Age 4 + 0.1863 Age 3 - 1.7141 Age 2 - 0.6472 Age + PCI = 0.001 Age 4 - 0.0312 Age 3 + 0.2715 Age 2 - 4.4837 Age + 99.752 100.77 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years New Construction -Arterials Prediction Model New Construction -Collectors Prediction Model 100 R² = 0.91 80 60 PCI 40 20 PCI = -0.0026 Age 4 + 0.0891 Age 3 - 0.9833 Age 2 - 0.8446 Age + 99.24 0 0 2 4 6 8 10 12 14 16 18 20 Age in Years New Construction -Residential Prediction Model 7 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Performance Models for Pavements that Received Overlay without Slurry Seal 100 100 R² = 0.97 R² = 0.96 80 80 60 60 PCI PCI 40 40 20 20 PCI = -0.0185 Age 4 + 0.5036 Age 3 - 4.0695 Age 2 + 3.6796 Age + PCI = -0.0004 Age 4 + 0.0099 Age 3 - 0.2232 Age 2 - 3.7809 Age + 98.809 99.192 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Overlay -Arterials Prediction Model Overlay -Collectors Prediction Model 100 R² = 0.91 80 60 PCI 40 PCI = -0.0048 Age 4 + 0.1177 Age 3 - 0.9078 Age 2 - 1.9824 Age + 20 98.666 0 0 2 4 6 8 10 12 14 16 18 20 Age in Years Overlay Residential Prediction Model 8 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Performance Models for Pavements with Slurry Seal:  Similar models were developed for:  Slurry seal for newly constructed pavements  Arterial  Collectors  Residential  Slurry seal for pavements that received overlay  Arterial  Collectors  Residential 9 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Prediction Performance Models New Construction - Arterial 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years New Construction Slurry Seal at year 0 New Construction Slurry Seal at year 1 New Construction Slurry Seal at year 3 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years New Construction Slurry Seal at year 5 New Construction Slurry Seal at year 7 New Construction Slurry Seal at year 9 10 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Prediction Performance Models Overlay - Arterial 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years Overlay New Construction Slurry Seal at year 0 New Construction Overlay Slurry Seal at year 1 New Construction Overlay Slurry Seal at year 3 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years New Construction Overlay Slurry Seal at year 5 New Construction Overlay Slurry Seal at year 7 New Construction Overlay Slurry Seal at year 9 11 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Prediction Performance Models New Construction - Collectors 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years New Construction Slurry Seal at year 0 New Construction Slurry Seal at year 1 New Construction Slurry Seal at year 3 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years New Construction Slurry Seal at year 5 New Construction Slurry Seal at year 7 New Construction Slurry Seal at year 9 12 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Prediction Performance Models Overlay - Collector 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years Overlay New Construction Slurry Seal at year 0 New Construction Overlay Slurry Seal at year 1 New Construction Overlay Slurry Seal at year 3 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years New Construction Overlay Slurry Seal at year 5 New Construction Overlay Slurry Seal at year 7 New Construction Overlay Slurry Seal at year 9 13 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Prediction Performance Models New Construction - Residential 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years New Construction Slurry Seal at year 0 New Construction Slurry Seal at year 1 New Construction Slurry Seal at year 3 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years New Construction Slurry Seal at year 5 New Construction Slurry Seal at year 7 New Construction Slurry Seal at year 9 14 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011

Prediction Performance Models Overlay - Residential 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years Overlay New Construction Slurry Seal at year 0 New Construction Overlay Slurry Seal at year 1 New Construction Overlay Slurry Seal at year 3 100 100 100 80 80 80 60 60 60 PCI PCI PCI 40 40 40 20 20 20 0 0 0 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 0 2 4 6 8 10 12 14 16 18 20 Age in Years Age in Years Age in Years New Construction Overlay Slurry Seal at year 5 New Construction Overlay Slurry Seal at year 7 New Construction Overlay Slurry Seal at year 9 15 University of Nevada Reno, www.wrsc.unr.edu 12/15/2011