su407.pdf

Date: August 7, 2013

DEPARTMENT OF TRANSPORTATION

STATE OF GEORGIA

SUPPLEMENTAL SPECIFICATION

Section 407—Asphalt-Rubber Joint and Crack Seal

Delete Section 407 and substitute the following:

407.1 General Description

This work includes filling (Type M) or sealing (Type S) joints and cracks in existing pavements with rubber asphalt mixtures.

A polymer-modified asphalt rubber (PMAR) blend may be used in lieu of both Type M and Type S.

407.1.01 Definitions

Type M: Used to fill joints and cracks in Portland cement concrete or asphaltic concrete pavements when required by the

Plans before placing an overlay.

Type S: Used to seal joints and cracks in Portland cement concrete and asphaltic concrete pavements and shoulders when not placing an overlay.

407.1.02 Related References

A. Standard Specifications

Section 820—Asphalt Cement

B. Referenced Documents

AASHTO T51

ASTM D 4

ASTM D 36

ASTM D 5329

ASTM D 7173

GDT-2

SOP 22

QPL 92

407.1.03 Submittals

Provide a Certificate of Analysis certifying each lot of premixed material meets the requirements of this Specification and submit the test results of each lot for each Project. Ensure each sealant lot is delivered in containers with the manufacturer’s name or trademark and lot number plainly marked.

When instructed by the Engineer, furnish premixed samples and samples of the individual components of premixed material as follows:

At least 20 lbs (10 kg) of rubber representative of each lot http://www.dot.ga.gov/doingbusiness/TheSource/special_provisions/shelf/sp820.pdf

At least 5 gal (18 L) of asphalt containing additives as proportioned

Proportional quantities of mixing aids or additives not included above

Packaged premixed sealant material weighing no more than 30 lbs (14 kg)

407.2 Materials

Ensure the sealant material is a premixed, asphalt-rubber sealant mixture evaluated in accordance with SOP 22 and listed on

QPLs 92-A, 92-B and/or 92-C . Ensure the mixture is a blend of asphalt cement, aromatic extender oil(s), and recycled or reclaimed tire crumb rubber with rubber contents meeting the requirements specified in Table 2. The blending will be conducted in a closely controlled manufacturing process as detailed in the manufacturer’s submitted Quality Control Plan.

Produce a mixture with the following properties:

A. Workability

The mixture pours readily and penetrates a 1/4 in (6 mm) pavement joint or crack to a depth of at least 1 in (25 mm) when the application temperature of the fully reacted mixture is 350 ºF (177 ºC) and the air temperature is 35 ºF (2 ºC) or higher.

The mixture, when placed in conventional field installation equipment, readily melts to a pumping consistency after being heated to 400 °F (204 °C) for 2 hours maximum. The mixture remains in a pumping consistency when the temperature of the field installation equipment is reduced to the normal operating temperature range of 300 ºF to 350 ºF

(149 ºC to 177 ºC).

B. Curing

The mixture contains no water or volatile solvents and cures immediately when cooled to a sufficient viscosity to prevent tracking caused by traffic.

C. Softening Point, Flexibility and Rubber Content.

When a fully reacted mixture sample of asphalt-rubber has been heated at 350 ºF (177 ºC) for one hour, or when a

PMAR blend has been heated at 380 ºF (194 ºC) for one hour, ensure it passes the following laboratory tests:

1. Softening Point

The minimum softening point by ring and ball described in ASTM D 36 is as follows:

Table 1 – Mininum Softening Point

PMAR 185 ºF (85 ºC)

Type S 135 ºF (57 ºC)

Type M 150 ºF (65 ºC)

2. Flexibility

Bend a 1/8 in (3 mm) thick x 1 in (25 mm) wide x 6 in (150 mm) long mixture specimen after conditioning to 10 ºF

(-12 ºC) at a minimum bending rate of 9 degrees per second(10 seconds maximum for a 90º bend) over a 1 in (25

mm) diameter mandrel without cracking.

3. Rubber Content %

Type M and Type S minimum rubber content % .

Table 2 – Type S and Type M Minimum Rubber Content

Type S 15% minimum

Type M 15% minimum

D. Separation

Test the PMAR blend for phase separation by pouring two representative samples of the mixture into aluminum tubes measuring 1 in (25 mm) in diameter and 5-1/2 in (140 mm) long as described in ASTM D 7173. Cure the samples at 325

ºF (163 ºC) for 48 hours. Take samples from the top and bottom of each tube and determine softening point as described in ASTM D 36. Average the test results from the top and bottom samples. If there is 4% or more difference between the average test result and either of the top or bottom test results, reject the mixture due to separation.

E. Adhesion

When cooled, the mixture bonds strongly to both asphalt and concrete pavement surfaces. The mixture contains no materials chemically reactive with these surfaces to reduce the short-term and long-term adhesion bonds.

F. Acceptable Recycled or Reclaimed Tire Crumb Rubber

Before the rubber is added, ensure the asphalt cement used in the mixture conforms to the requirements of

Subsection 820.2.01, PG 58-22 or PG 64-22.

Ensure the recycled, reclaimed tire crumb rubber used in the mixture meets the following requirements:

Obtained from used pneumatic tires (such as automobile, truck, bus, etc.)—not solid tires and non-tire rubber sources

Produced from an ambient or cryogenic grinding process (crushes, tears, factures or grinds, the used rubber tires and produces rubber particles with a ragged, sponge-like surface). Tire buffings are prohibited.

Contains recycled, vulcanized crumb rubber and/or reclaimed (devulcanized) rubber

Contains at least 25 percent natural rubber by weight of the total rubber portion of the mixture

Contains no more than 0.1 percent fabric

Free of wire and other contaminating materials, except up to four percent calcium carbonate or talc to prevent rubber particles from sticking

Contains no rubber particles greater than 1/4 in (6 mm) long

Meets the following gradation requirements:

Table 3 – Recycled or Reclaimed Tire Crumb Rubber Gradation

Sieve Size Percent Passing

No. 10 (2.0 mm) 100%

No. 16 (1.18 mm) 95 to 100%

No. 30 (600 µm) 40 to 80%

No. 80 (180 µm) 0 to 5%

G. Polymer-modified Asphalt Rubber

If a PMAR blend is used, ensure it meets the following additional requirements:

Table 4 – Polymer-modified Asphalt Rubber Properties (PMAR)

PROPERTY SPECIFICATION LIMITS

Cone Penetration, 77 ºF (25 ºC) (ASTM D 5329) 30 - 60 dmm

Resilience, 77 ºF (25 ºC), % Recovery (ASTM D 5329) 30% minimum

Ductility, 77 ºF (25 ºC), 50 mm/minute (ASSHTO T-51) 300 mm minimum

Asphalt Compatibility (ASTM D 5329) Pass

Bitumen Content (ASTM D 4) 60 – 70 %

Tensile Adhesion (ASTM D 5329) 350 % minimum

Rotational Viscosity (Brookfield), No. 5 spindle, 20 RPM, 400 ºF (205 ºC)

3,000 – 15,000 cp

Rubber Content % (GDT-2) 12% minimum

407.2.01 Delivery, Storage, and Handling

Package the premixed sealant material in units weighing no more than 30 lbs (14 kg) with a maximum of two 30 lb (14 kg) units per shipping container. Ensure the plastic film used to package the units melts at normal application temperatures when placed in the installation equipment.

407.3 Construction Requirements

407.3.01 Personnel

General Provisions 101 through 150.

407.3.02 Equipment

A. Field Installation Equipment

Use field installation equipment that produces or maintains specified temperatures, even if filled to capacity.

Ensure the equipment produces or maintains a homogenous mixture of asphalt and rubber at a uniform temperature without hot or cool spots or rubber and asphalt segregation in the mixture.

B. Crack Filling Equipment

Ensure the equipment for filling the joints and cracks directs the sealant into the crack. Seal large cracks from the bottom

up. Provide squeegees as necessary.

C. Air Compressor(s)

Ensure the air compressors are satisfactory to the Engineer.

407.3.03 Preparation

A. Joint and Crack Preparation

Use compressed air to thoroughly clean the joints and cracks to be sealed.

Clean the pavement surface and check the joints and cracks to ensure they are free of vegetation, dirt, dust, moisture, and other foreign material.

407.3.04 Fabrication

General Provisions 101 through 150.

407.3.05 Construction

A. Restrictions

Do not seal joints and cracks if:

The joint or crack surface to be treated is not thoroughly dry.

Rain is imminent.

The air temperature is below 35 ºF (2 ºC).

B. Procedure

Follow this procedure to seal joints and cracks:

1. Place the prepackaged sealant mixture in the field installation equipment.

2. Heat the sealant mixture for the proper time and temperature to provide a full reaction between the asphalt and rubber.

3. Apply the mixture at the specified application temperature according to the manufacturer’s recommendations or the laboratory’s approval.

4. Carefully fill the joint or cracks, slightly overfull. Strike off the excess with a V-shaped squeegee to feather the sealant out to a width of approximately 2 in (50 mm).

407.3.06 Quality Acceptance

If the packaged units are bonded or stuck together or to the shipping container, or if packaging staples or fasteners cause sealant contamination, the material may be rejected as determined by the Engineer.

The manufacturer must meet the requirements of this Specification and furnish evidence of successful field installation and performance under similar environmental and project conditions.

407.3.07 Contractor Warranty and Maintenance

General Provisions 101 through 150.

407.4 Measurement

Joints and cracks will be measured by the linear foot (meter) by surface measure.

407.4.01 Limits

General Provisions 101 through 150.

407.5 Payment

Joints and cracks sealed according to the Plans and this Specification will be paid for at the Contract Unit Price bid.

Payment is full compensation for furnishing all materials and performing the work.

Payment will be made under:

Item No. 407 Polymer-modified asphalt–rubber joint and crack seal Per linear foot (meter)

Item No. 407 Asphalt-rubber joint and crack seal, type “S” Per linear foot (meter)

Item No. 407 Asphalt-rubber joint and crack seal, type “M” Per linear foot (meter)

407.5.01 Adjustments

General Provisions 101 through 150.

Office of Materials and Testing