Transcript SECTION 39, “Hot Mix Asphalt” Training
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Caltrans Changes SECTION 39
“Hot Mix Asphalt”
Presented by: Terrie Bressette Caltrans
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What Changed?
TERMS
Hot Mix Asphalt (HMA) = Asphalt Concrete (AC) Rubberized HMA (RHMA) = Rubberized AC (RAC) Open Graded Friction Course (OGFC) = OGAC RHMA-G = RAC (Type G) RHMA-O & -O-HB = RAC (Type O) & (Type O-HB) Tack Coat = Paint Binder (Tack Coat) Geosynthetic Pavement Interlayer = Pavement Reinforcing Fabric (PRF)
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What Changed?
Section 39 – AC vs. HMA
Old Standard Specifications
Section 39 – AC = 12,000 Words
New “Amended to Read”
Section 39 – HMA = 18,000 Words
SSPs
Section 39 AC = 21 SSPs
58,000 Words
Section 39 HMA = 12 SSPs
28,500 Words
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What Changed?
Standard Special Provisions 12 SSPs from 30+ Old SSPs
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39-AAA – HMA Type A & B
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39-BBB – OGFC 39-CCC – RHMA-G 39-DDD – RHMA-O & RHMA-O-HB 39-EEE – HMA (Misc. Areas) 39-FFF – Minor HMA 39-GGG – Rumble Strips (Ground in) 39-HHH – HMA-Lime Slurry 39-III – HMA-Dry Lime 39-JJJ – HMA-Liquid Anti-Strip 39-KKK – Prime Coat 39-LLL – Replace AC Surface
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What Changed?
Standard Special Provisions New SSPs
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39-MMM – Large Stone Mix
• • •
39-NNN – High Stability Mix 39-OOO – Bonded Wearing Course (Gap-Graded) 39-PPP – Bonded Wearing Course (Rubberized)
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District Requested
Extra testing required by aggregate issues Lime-slurry marination required
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Section 39 – CHANGES Mix Designs
Still Hveem Method of Mix Design Dense Graded
– HMA (Type A & B)
Rubberized HMA
– RHMA-G
Mix Design by Producer State Verifies JMF with Plant Mix Mix design good for 12-months Flat & Elongated
Open Graded
– OGAC, RHMA-O & O-HB
Aggregate qualities and gradation by Producer State determines asphalt content Mix design good for 12-months
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Section 39 – CHANGES Materials
Aggregate Qualities
Gradation
LA Rattler Sand equivalent
% Crushed Particles Fine Aggregate Angularity Flat & Elongated (TV ± Tolerance) (2-face – New) (New) (New)
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Section 39 – CHANGES Materials
Mix Qualities
Binder Content Air voids content
Stability
HMA moisture content
(Mix & Production) Voids in Mineral Aggregate
(
Mix Design & Verification)
Voids Filled with Asphalt Dust Proportion (Mix Design Only) (Mix Design Only)
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Section 39 – CHANGES Materials
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CT371 Pilot
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California Test (CT) 371
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AASHTO T283-03 In QC/QA projects for 2 years
Estimate approx 25 projects / year •
Producer tests mix with CT371
Chooses treatment choice (TSR 70)
Test HMA at least once during production District & Translab tests also (FIO) Data analysis – repeatability, lab / lab, mix vs. production
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Section 39 – CHANGES Construction
Processes –
Standard
HMA (Type A & B) RHMA-G
OGAC & RHMA-O
Method
Small quantities
QC/QA - >10,000 tons
HMA (Type A & B) RHMA-G
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Section 39 – CHANGES (3 Construction Processes) Standard –
Applies to the majority of HMA.
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Contractor QC plan & tests at least twice daily Compaction (91 – 97% of Rice) State will test and results will be used for acceptance and pay
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Section 39 – CHANGES (3 Construction Processes) Method –
Applies to very small quantities of HMA • •
The contractor will not perform QC Method compaction with roller and temperature requirements
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State will test and results will be used for acceptance and pay.
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Default for compaction when layer <0.15-ft
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Section 39 – CHANGES (3 Construction Processes) QC/QA –
All HMA quantities greater than 10,000 tons.
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QC tests for each 750 tons of HMA
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State will verify gradation & % binder
1 verification per 5 QC tests •
Statistical evaluation of gradation, % binder and compaction for pay.
Verified contractor QC for gradation & % binder Sate cores for compaction (92 – 96% of Rice)
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Section 39 – CHANGES Production
Materials Production Quality Program –
HMA & PCC (soon)
Weights and Measures
Safety Limited production unit requirements
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Section 39 – CHANGES Placement
Lift Thickness > 3 X NMAS
e.g.
¾-inch mix = 0.20-ft layer and above ½-inch mix = 0.125-ft layer
Must comply for compaction Contractor may change gradation of mix if ¾” mix and 0.15 to 0.20 layer Not required for Method
Thin blanket – Maintenance
Leveling, etc.
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Section 39 – CHANGES
HMA must meet all specification requirements throughout production and placement.
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First out of spec = Contractor Fix
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Second out of spec = Stop, test, show RE before starting up
In-place & out-of-spec material
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RE determines status on case-by-case
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