MGPEC’s Slurry Seal Specification Tweaks For

Scott WengerCity of Thornton

scott.wenger@cityofthornton.net720-977-6250

Monday, March 11, 13

MGPEC’s Goal For • Uniform standardized specifications• Uniform design• Uniform construction and maintenance

practices• To advance improvements together

through positive working relationships

Monday, March 11, 13

Why the changes?

• Last version was 2001• Update to current industry standards

and practices– Contractors and suppliers reviewed and

commented as the changes progressed• Uniform quality control• To provide helpful information for

Monday, March 11, 13

16.2 MATERIALS

• 16.21 Emulsified Asphalt– CQS1hL Emulsion is the only choice for

emulsion– The other two choices were deleted since

they were never used

Monday, March 11, 13

Changes to the Emulsified Asphalt Table

Test Quality Specification

AASHTO T59

ASTM D88 

ASTM D6933ASTM D6934

AASHTO T49 1

ASTM D5¹

ASTM D113 ¹

ASTM D2042 ¹

AASHTO T 53 ¹

ASTM D36 ¹

Saybolt Furol Viscosity

at 77° F (25° C)20 to 100 Sec.

Storage Stability See 16.22 StorageSieve Test 0.10 Max

Residue From Evaporation

60%Penetration at 77° F

(25°C)

100 g, 5 Sec.

40 to 90 **

Ductility at 77° F (25° C)

5 cm/min. cm

40 Min.

Solubility in Trichloroethylene 97.5 Min.

Softening Point 3% Latex, 148° F Min.

1 Test on residue from evaporation.**Climate conditions should be considered when using this range. The mix designer may suggest a range higher or lower than the suggested range.

Monday, March 11, 13

Changes to the Aggregates Table (16.23)

Test Quality Specification

AASHTO T176 **ASTM D2419 **

AASHTO T104ASTM C88

AASHTO T96

ASTM 131

Sand Equivalent 60 Min. Method B (wet)

Soundness15% Max. using NA2 SO4

Or 25% Max. using MgSO4

Abrasion Resistance

25% Max. Grading D

Sand Equivalent changed from 55 Min. to 60 Min. Method B (Wet)

Monday, March 11, 13

POLYMER MODIFIER16.27 - 3% Polymer Modifier Was Added for Better Performance

Slurry Sealed 10 years agoMonday, March 11, 13

16.3 MIX DESIGNMIXTURE PROPERITIES

Test Description Specification

ISSA T-106

ISSA TB-139(for quick-traffic systems)

 

Additives

ISSA TB-109

ISSA TB-114

ISSA TB-100

ISSA TB-113

Residual Asphalt

Mineral Filler

Emulsion Content

Slurry Seal Consistency

.079 – 1.18 inches(2.0 – 3.0 cm)

Wet Cohesion 30 minutes minimum

(set)Wet Cohesion 60 minutes Minimum

12 kg-cm Minimum 

20 kg-cm Minimum

  As neededExcess Asphalt

By LWT Sand Adhesion50 g/ft2 Max. (538 g/m2 max)

Wet Stripping Pass(10 minutes boiling

water)

Pass (90% Min.)Wet Track Abrasion

Loss(6-Day soak)

75 g/ft2 Max. (807 g/m2)

Mix Time 180 seconds min. AT 77° F **70 seconds min. at 100° F **

10 – 16% (for type I)7.5 – 13.5% (for type II)6.5 – 12 % (for type III)

Based on dry weight of aggregate.

0.0% to 3.0% Based on dry weight of aggregate13 – 18% (for type I)

12.4 – 22.5% (for type II)

10.8 – 20% (for type

Based on dry weight of aggregate plus any mineral filler

Emulsion Content will vary based on the mix design.

Monday, March 11, 13

16.5 CALIBRATION• Slurry Calibration Procedures were

added to the end of the specification.• Accurate Calibration is crucial for

Slurry Seal performance• Will provide information for inspection

but could change in the field.

Monday, March 11, 13

CALIBRATION

Monday, March 11, 13

16.6 WEATHER LIMATIONS

• Slurry may be applied when air or surface temperature is 45 degrees and rising– Deleted 50 degrees and falling.

• Note: The contractor is still liable for the slurry seal warranty per bid specifications.

Monday, March 11, 13

16.82 REMOVAL OF PAVEMENT MARKINGS

• ITEMS ADDED:• Removal of Thermo Plastic pavement

markings.• Removal of Preformed pavement

markings.– Removal due to thickness of markings.

• PAINT DOES NOT NEED REMOVAL– This includes temporary paint during

Monday, March 11, 13

16.9 APPLICATION

AGGREGATE TYPE LOCATION

APPLICATION RATE(Dry weight of

aggregate)

Type I

Type II

Type III

Parking areasLocal and Secondary Roadways

Airport Runways10 - 14 lb/yd²

Parking areasLocal and Secondary Roadways

Airport Runways17 - 20 lb/yd²

Primary and Interstate Roadways 15 - 22 lb/yd²

Monday, March 11, 13

16.15 CLEAN UP• The CONTRACTOR shall expose utility

access points and remove any debris associated with the performance of the work on a daily basis.– Added to keep the project safe, clean and

accessible for utility operations.– If utility access points are covered for a

few weeks it can lead to unwanted issues for emergency and maintenance crews.

Monday, March 11, 13

16.16 TOLERANCESUNIT PRICE REDUCTIONS

Variation Below Specifications

Unit Price Reduction

Emulsion 1 – 5% 5% 6 – 10% 10% 11 – 15% 15% 16%+ 20%

Aggregate 1 – 5% 5% 6 – 10% 10% 11 – 15% 15% 16%+ 20%

• PRIOR SPECIFICATIONS HAD NO PRICE REDUCTIONS.

Monday, March 11, 13

16.17 MEASUREMENT• Slurry seal will be measured and paid

by the square yard placed.• The CONTRACTOR shall provide

aggregate and emulsion tickets on a daily basis.– This is an aid for checking the quantities.

• The CONTRACTOR shall provide a daily log of the square yards placed and

Monday, March 11, 13

16.18 TESTING AND QUALITY ASSURANCE SAMPLING AND

TESTINGTest Type Test Standard Recommended Frequency

Residue From Evaporation1 Qt. sample

Aggregate Gradation

Polymer Content1 Qt. sample

Separation Test

Sand Equivalent

Soundness of Aggregate

Abrasion Resistance of Aggregate

Application Rate

ASTM 6934 1 / Batch

AASHTO T 2ASTM D 75

1 / Source

AASHTO T 302 1 / Batch

Observation¹ DailyAASHTO T 176*ASTM D 2419*

60 Min. Method B (wet)1 / Source

AASHTO T 104ASTM C 88

1 / Source

ASHTO T 96ASTM C 131Grading D

1 / Source

  Daily

Monday, March 11, 13

Recommended publications• www.mgpec.org• www.slurry.org

– Inspectors manual

Monday, March 11, 13

Questions

?Monday, March 11, 13