Part 1 — General
1.1 Section Includes
A.Placing a mixture of fine graded aggregate, mineral filler, emulsified asphalt, and water.
1.2 RELATED SECTIONS Not Used
1.3 References
A.AASHTO M 17: Mineral Filler for Bituminous Paving Mixtures
B.AASHTO M 29: Fine Aggregate for Asphalt Mixtures
C.AASHTO M 208: Cationic Emulsified Asphalt
D.AASHTO T 11: Material s Finer than 75- µm (No. 200) Sieve in Mineral Aggregates by Washing
E.AASHTO T 27: Sieve Analysis of Fine and Coarse Aggregates
F.AASHTO T 96: Resistance to Degradation of Small -Size Coarse Aggregate by Abrasion and Impact in the Los Angeles Machine
G.AASHTO T 104: Soundness of Aggregate by Use of Sodium Sulfate or Magnesium Sulfate
H.AASHTO T 176: Plastic Fines in Graded Aggregates and Soils by Use of the Sand Equivalent Test
I.AASHTO T 278: Surface Frictional Properties Using the British Pendulum Tester
J.AASHTO T 279: Accelerated Polishing of Aggregates Using the British Wheel
K.International Slurry Seal Association ( ISSA ) A105 Guidelines
L.UDOT Quality Management Plan
M.UDOT Minimum Sampling and Testing Requirements
1.4 DEFINITIONS Not Used
1.5 Submittals
A.Mix Design and test results for review .
1.Meet the requirements of this Section, Article 2.7.
2.Include target gradation for combined aggregate and mineral filler.
3.Additive list and dosage rates from mix design.
B.Test reports for aggregate for information.
1.Meet the requirements of this Section, Article 2.2.
C.Manufacturer’s Certificate of Compliance for Mineral Filler for information.
D.Verification that the emulsified asphalt supplier adheres to UDOT Quality Management Plan 508 Asphalt Emulsion for information.
1.Certificate of analysis/compliance from the manufacturer for each shipment.
1.6 Acceptance
A.Sampling and testing of material is according to UDOT Minimum Sampling and Testing Requirements.
B.Meet the Target Tolerance of Table 1.
Part 2 — Products
2.1 Emulsified Asphalt
A.Use a cationic emulsified asphalt grade CQS -1h according to AASHTO M 208.
2.2 Aggregate
A.Use 100 percent manufactured sand, slag, crushed fines, or a combination. Refer to AASHTO M 29.
B.Use aggregate that is clean and free from organic matter or other detrimental substances.
C.Use an aggregate blend with a sand equivalent of 45 or more. Refer to AASHTO T 176 .
D.Meet a minimum polishing value of 31. Refer to AASHTO T 278 and AASHTO T 279.
E.Use aggregate with 35 percent or less loss by abrasion. Refer to AASHTO T 96 .
F.Meet 15 percent soundness maximum using Na 2 SO 4. Refer to AASHTO T 104.
2.3 Mineral Filler
A.Use Portland Cement, hydrated lime, or aluminum sulfate. Refer to AASHTO M 17.
2.4 Combined Aggregate and Mineral Filler
A.Use a job mix or target gradation within the gradation band.
1.Base the mix design on this gradation.
2.The percent passing each sieve after the target gradation has been submitted will not vary by more than the target tolerance and still remain within the gradation band in Table 1.
3.Refer to AASHTO T 11 and AASHTO T 27. Table 1 Gradation Sieve Size Gradation Band (% Passing) Target Tolerance ⅜ inch 100 No. 4 70-90 +/- 5% No. 8 45-70 +/- 5% No. 16 28-50 +/- 5% No. 30 19-34 +/- 5% No. 50 12-28 +/- 4% No. 100 7-18 +/- 3% No. 200 5-15 +/- 2%
2.5 Water
A.Potable and free from harmful salts and contaminants.
2.6 Additives
A.Additives may be used to accelerate or retard the break -set of the slurry seal or to improve the resulting finished surface.
2.7 Slurry Seal Mix Design
A.Use a Department approved laboratory that is qualified to perform the ISSA A105 tests listed in Table 2.
1.Use the same materials and aggregate gradation to be used on the project. Table 2 TESTS ISSA TEST NO. DESCRIPTION SPECIFICATION ISSA TB 106 Slurry Seal Consistency 2cm Minimum 3cm Max imum ISSA TB- 139 For quick -traffic systems Wet Cohesion 30 Minutes Minimum (Set) Wet Cohesion 60 Minutes Minimum 12 kg -cm Minimum 20 kg- cm Minimum ISSA TB 109 For heavy -traffic areas only Excess Asphalt by LWT Sand Abrasion 50 g/ft2 Maximum (538 g/m2 Maximum) ISSA TB -114 Wet Stripping Pass (90% Minimum) ISSA TB-100 Wet-Track Abrasion Loss, One-hour Soak 75 g/ft2 (807 g/m2) ISSA TB- 113 Mix Time** Controllable to 180 Seconds Minimum ** Perform the mixing test and set -time test at the highest temperatures expected during construction.
2.8 Equipment
A.Use only a machine designed and manufactured specifically for blending, mixing, and placing slurry seal.
1.Mix the material in a self -propelled, slurry seal mixing machine of either truck -mounted or continuous -run design.
a.Continuous -run machines – Equipped to self -load materials while continuing to lay slurry seal.
b.Either type machine – Accurately deliver and proportion the aggregate, emulsified asphalt, mineral filler, control setting additive, and water to a revolving mixer and to discharge the mixed product on a continuous -flow basis.
2.Maintain sufficient storage capacity within the machine for aggregate, emulsified asphalt, mineral filler, control additive , and water to maintain an adequate supply to the proportioning controls.
B.Calibrate each mixing unit in the presence of the Engineer before a machine is used on a project
Part 3 — Execution
3.1 Limitations
A.Do not apply slurry seal during rain, when road surface moisture is present, or during other adverse weather conditions.
B.Do not apply slurry seal if either the pavement or air temperature is below 50 degrees F.
C.Do not apply slurry seal when the temperature is projected to be below 33 degrees F within 24 hours of placing slurry seal.
D.Keep traffic off roadway surface until the slurry seal has cured.
3.2 Stockpil E
A.Remove material not meeting specifications from the stockpile area.
B.Stockpiles not meeting gradation requirements may be corrected and must be retested before use.
3.3 Preparation
A.Clean the surface of all dirt, sand, dust, oil, and other objectionable material immediately before applying the slurry.
B.Allow cracks to dry thoroughly before applying slurry seal when using water to clean the surface.
C.Protect manholes, valve boxes, drop inlets , and other service utility entrances before surfacing.
3.4 Application
A.Pre-wet the entire surface by fogging ahead of the slurry box.
1.Do not over apply, causing free water to sit on the pavement in front of the slurry box.
B.Use additives as required in accordance with the authorized additive list and dosage rates submittal.
C.Carry a sufficient amount of slurry in all parts of the spreader at all times so that full width and complete coverage is obtained with no streaks or narrow spots.
1.Avoid overloading the spreader.
D.Apply slurry mixture of proper consistency at an average rate of 18 to 22 lb/yd 2 of dry aggregate .
E.Do not add additional water for any reason, once the mixture has been placed onto the road surface.
F.Remove and replace the slurry if any of the following occurs:
1.Lumping, balling, or unmixed aggregates .
2.Separation of the coarse aggregate from the emulsion and fines .
3.Settling of the coarse aggregate to the bottom of the mix .
4.Excessive breaking of emulsion inside the spreader box .
5.Streaking caused by oversized aggregate .
3.5 Finishing Details
A.Do not create build- up when constructing longitudinal and transverse joints.
B.Place slurry seal adjacent to concrete pavements or concrete curb and gutter with a straight longitudinal edge.
1.Do not allow over -lap on these areas.
2.Remove slurry seal placed on concrete .
C.Maintain straight lines at all locations.
D.Place slurry seal at side streets and intersections out to right -of-way line.
E.Use hand squeegees to spread slurry in areas that cannot be reached with slurry seal machine.
1.Lightly dampen areas before mix placement.
2.Provide complete and uniform coverage.
3.Avoid unsightly appearance from hand work.
4.Use the same type of finish in hand worked areas as applied by the spreader box.
F.Use construction paper or comparable products so all beginning and ending joint lines from each construction pass are straight.
Source: Utah Standard Specifications for Road and Bridge Construction, 2026 Edition. Pages 631–637 of 1,331.