Pavement Treatment Testing

Pavement Treatment Testing - San Joaquin Road

A 4.3-mile section of San Joaquin Road between Old Ajo Highway and Milky Way Drive has been selected as a testing ground for several pavement treatments.

Treatments will be tested for various factors to ascertain life-cycle return on investment leading to more cost-effective selection of pavement treatments for use in Pima County testing.

The treatments will be laid in multiple 1,000-foot test sections covering both directions of traffic. Pima County will group the treatments by color and texture to minimize the visual patchwork. The balance of the roadway will be repaved by removing 2 inches of existing asphalt and replacing it with 2 inches of traditional asphalt. The result will be the complete repair of a 4.3-mile section of roadway that has fallen into poor condition.

The Department will evaluate the wear to test segments every six months, and forecast performance each treatment over time. The County will also study the road over several years to determine the best, most cost-effective and long-term treatment options. Construction is scheduled for this summer with treatments to include:

• Section 1: 1-inch Green Asphalt overlay with fiber southbound lane only 
• Section 2: 1-inch PAG 3 terminal blend overlay
• Section 3: 2-inches PAG 2 overlay
• Section 4: 2-inches PAG 2 with fiber overlay
• Section 5: Pulverize 6-inches existing and compact with double chip seal & fog seal
• Section 6: Pulverize 6-inches existing and compact with single chip seal & micro surface
• Section 7: Pulverize 6-inches existing and compact with single chip seal & fog seal
• Section 8: Pulverize 6-inches existing and compact cement treated (300 psi) with chip seal & rubberized (terminal blend) chip seal & fog seal
• Section 9: Pulverize 6-inches existing and compact cement treated (150 psi) with chip seal & fog seal
• Section 10: 2"-inches PAG 2 mill & fill
• Section 11: Pulverize 6-inches existing and compact cement treated (300 psi) with chip seal & fog seal
• Section 12: 6-inches roller compacted concrete
• Section 13: Double chip seal overlay & fog seal
• Section 14: Rubberized (terminal blend) single chip seal overlay & fog seal

Evaluation of the test treatments are scheduled to occur six months post construction and at annual intervals thereafter. Observations will include: cracking, rutting, oxidation, surface wear and roughness, supplemented by the regional Pima Association of Governments/City of Tucson Automated Road Analyzer van and additional laboratory tests as needed.

Treatment-specific curves will be developed based on data from each evaluation interval to rank treatment benefit-cost projection based on standardized return on investment criteria. These curves will be correlated against longer-term national research data for that treatment type, to infer longer term performance from shorter observation periods. The treatment curves will be controlled to account for minor localized variations in soil or drainage conditions.

Construction Plans

• Construction Plans San Joaquin

Specifications

• Specifications

 

Pavement Condition Log

 

San Joaquin Pavement Condition Survey Log

Test Section	Description	Pavement Condition Index			Average Cost per Lane Mile
		December 2019	August 2020	May 2021
PAVEMENT SECTIONS
1N	1-inch Green Asphalt overlay over existing pvmt northbound lane	100	92	81	$53,400
1S	1-inch Green Asphalt overlay with fiber over existing pvmt southbound lane	100	89	78	$57,400
2	1-1/4" asphalt overlay (PAB 3, PG 70-22TR) over existing pvmt	100	99	85	$59,000
3	2" asphalt overlay PAG 2 over existing pvmt	100	100	97	$75,500
4	2" asphalt overlay PAG 2 with fiber over existing pvmt	100	99	85	$109,000
5	Fog seal, double chip seal Class 1, pulverized & recompact 6" of existing pvmt & subgrade	92	90	83	$77,500
6	Microsurface, chip seal Class 1, pulverized & recompact 6" of existing pvmt & subgrade	94	91	87	$114,000
7	Fog seal, chip seal Class 1, pulverized & recompact 6" of existing pvmt & subgrade	87	87	79	$54,000
8	Fog seal, double chip Class 1 & rubberized chips, pulverized & recompact 6" w/2 lbs cement/sf	93	87	87	$122,000
9	Fog seal, chip Class 1, pulverized & recompact 6" with 1 lbs of cement/sf	91	91	85	$90,000
10	2" mill and fill (PAG 2) over existing pvmt	100	99	98	$109,000
11	Fog seal, double chip seal Class 1, pulverized & recompact 6" with 2 lbs of cement/sf	90	82	75	$106,000
12	6" rolled compacted concrete, remove 4-inches below existing top of pavement	92	91	89	$467,500
SURFACE TREATMENTS
13	Fog seal, double chip Class 2/Class 1 over existing pavement	79	79	74	$37,500
14	Fog seal, double chip rubberized precoated chips over existing pvmt	82	82	74	$22,000

Performance Curves 

Test Sections 1 (northbound)

Test Section 1 (southbound)

Test Section 2

Test Section 3

Test Section 4

Test Section 5

Test Section 6

Test Section 7

Test Section 8

Test Section 9

Test Section 10

Test Section 11

Test Section 12

Test Section 13

Test Section 14

Photographs

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Progress Update

SAN JOAQUIN PAVEMENT TREATMENT TESTING PROGRAM PIMA COUNTY DEPARTMENT OF TRANSPORTATION PROGRESS UPDATE
Date	Description
April 2018	Development of drawings and specifications started.
June 2018	Drawings/Specifications completed and sent out to bid.
August 2018	Southern Arizona Paving awarded contract. Total Estimate Cost = ±$1.1M
September 2018	Construction started.
December 2018	Construction completed.
March 2019	Visual inspection of roller compacted concrete test section conducted by Jim Cunningham, DOT Deputy Director (Memorandum): Surface in good condition. Profile not as smooth as asphalt but is considered adequate for the speed.
December 2019	Infrastructure Management Services (IMS) conduct pavement condition assessment survey.
August 2020	Infrastructure Management Services (IMS) conducted pavement condition assessment survey.
May 2021	Infrastructure Management Services (IMS) conducted pavement condition assessment survey.
July 2021	Memorandum of July 14, 2021 to County Engineer on program status.

 

• San Joaquin Road Pavement Treatment Testing Program Status Update Memorandum