Part 1 — General
1.1 Section Includes
A.Products and procedures for incorporating hydrated lime into all asphalt mixes.
1.2 RELATED SECTIONS Not Used
1.3 References
A.AASHTO M 303: Lime for Asphalt Mixtures
B.ASTM C 110: Physical Testing of Quicklime, Hydrated Lime, and Limestone
C.ASTM C 1097: Hydrated Lime for Use in Asphalt Cement or Bituminous Paving Mixtures
D.ASTM C 1602: Mixing Water Used in the P roduction of Hydraulic Cement Concrete
E.UDOT Materials Manual of Instruction
F.UDOT Quality Management Plans
1.4 DEFINITIONS Not Used
1.5 SUBMITTALS Not Used
1.6 Quality Assurance
A.Use a supplier of Hydrated Lime that is pre- qualified through UDOT Quality Management Plan 510.
B.Comply with UDOT Quality Management Plan 514 , Asphalt Mix.
Part 2 — Products
2.1 Hydrated Lime
A.Hydrated Lime – Refer to AASHTO M 303, Type I.
1.Refer to ASTM C 1097 , Physical Requirements .
2.Use test method ASTM C 110.
2.2 Water
A.Use potable water or water according to ASTM C 1602.
Part 3 — Execution
3.1 Application
A.Add hydrated lime to all asphalt pavement mixes.
1.Add lime as determined in the approved mix design.
2.Base the amount of hydrated lime used on the dry weight of the virgin aggregate.
3.Use either Method A or B, unless Method B is specified .
4.Use Method A only when the mix is produced by a Certified Asphalt Mix Supplier. Refer to the UDOT Quality Management Plan 514 Asphalt Mix.
B.Method A – Dynamic Feed Lime Slurry
1.Lime Slurry –At least three parts water to one part lime by weight.
a.Adjust t he amount of added water to meet the 3:1 lime slurry to account for the moisture in the stockpile.
b.Use lime slurry with a minimum of one part water by weight of lime.
2.Add at least 1 percent lime by weight of the virgin aggregate .
3.Deliver lime slurry to the twin shaft pugmill for mixing with aggregate.
a.Use a virgin aggregate/lime mixture that contains at least 3 percent water by weight of the virgin aggregate after the pugmill.
4.Adjust quantity (percent) of lime as necessary , based on results of Hamburg Wheel Tracker test.
5.Verify that Lime Slurry equipment is operating at all times.
a.The Engineer may require Method B, marination of the aggregate/hydrated lime mix ture in the stockpile if the Asphalt Mix is supplied without hydrated lime slurry treatment.
C.Method B – Lime and Aggregate Stockpile Marination
1.Method B is an option for a C ertified Asphalt Mix Supplier.
2.Method B is required for all Asphalt Mix Suppliers that are not certified according to the UDOT Quality Management Plan 514 Asphalt Mix.
a.The Engineer will inspect the marination process when the Asphalt Mix supplier is not certified at the time of production.
3.The Department applies a deduction for mix produced by a non- certified supplier to cover the cost of the inspection.
a.The deduction is according to the UDOT Qual ity Management Plan 514 Asphalt Mix.
4.Provide sufficient free moisture to thoroughly wet the aggregate and activate the lime before introducing hydrated lime.
a.The aggregate/lime mixture will contain at least 3 percent water by weight of the virgin aggregate.
5.Add at least 1½ percent lime by weight of the virgin aggregate.
6.Thoroughly mix wet aggregate/lime mixture in a twin shaft pugmill.
7.Marinate the aggregate/lime mixture in the stockpile for at least 48 hours.
8.Adjust quantity (percent) of lime as necessary , based on results of Hamburg Wheel Tracker test , UDOT Materials Manual of Instruction 990.
9.Use the wet cured aggregate within 60 days except as otherwise provided in the UDOT Qual ity Management Plan 514 Asphalt Mix.
D.Mixing Methods A and B – Provide a horizontal twin shaft pugmill .
1.Adjust mixing paddles in the pugmill so that the aggregate being discharged is completely coated by the lime slurry.
2.Do not allow volume of material in the pugmill to extend above the vertical position of the blade tips.
3.2 Quality Control
A.Tolerance Controls
1.Tolerance lime weight vessel s tatic calibration ± 1.5 percent
2.Dynamic delivery calibration ± 1.5 percent
3.Inlet flow meter ± 2 percent
4.Discharge flow meter ± 1.5 percent
Source: Utah Standard Specifications for Road and Bridge Construction, 2026 Edition. Pages 528–530 of 1,331.