Bituminous Update2019 Metro State Aid Construction Seminar

Greg Johnson (Assistant Bituminous Engineer)

& Deb Evans (Mix Design Specialist)February 13, 2019

mndot.gov

Every Road Tells a Story

Project Goals

• Problem to Solve

• What will be considered a Success

• Realistic

• Budget

Plant Documentation

• Test Summary Spreadsheet

• AC Bill of Lading

• Scale Checks

• Recordation File

• Plant Diary

• Plant Certification

• MDR

• Weigh Ticket

Field Documentation

• Emulsion Bills of Lading

• Core Stationing Worksheet

• Core Incentive/Disincentive Worksheet

• Pavement Smoothness Files (*.ERD files)

• Pavement Smoothness Worksheet

• Street Diary

• Emulsion Lab Results

• Asphalt Binder Lab Results

Spec Change One Percent Reduced Density

• Change in 2018 Spec book.

• Contractor has to request to have One Percent Reduced Density.

• The Contractor still has to do it by the end of the 3rd day of paving and in writing!

• 1% reduced is required when paving the 1st lift over concrete.

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Longitudinal Joint Density Requirement

Table 2360-20Longitudinal Joint Density Requirement

Location Confined Edge of Mat* Unconfined Edge of Mat║

Long joint 4% Design Void 91.0 89.5 89.5 88.1

Long joint 3% Design Void 92.0 90.5 90.5 89.1

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Starting with the March 2019 Letting

AASHTOware

• What is It?

• MnDOT’s software to house Construction & Materials Data

• When?

• 2020 for Materials

• How will it affect you?

• Currently – Nothing

• This Summer - MnDOT use Excel Spreadsheets instead of LIMS

• Future – Electronic sample cards, reports, database

Tack

• Field Staff must sample 1/50,000 gallons

• Submit in ½ gallon plastic container

• (Identify dilution = CSS-1H, CSS-1H D30, or CSS-1 D50)

• Failures (2018)

• 397 samples – 42 tack (18%) and 3 (2%) chip seal/Micro/CIR,etc.

• Of the 42 failures = 23 were Residue, 14 were Penetration, and 5 were Both

• Causes:

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ResiduePenetrationNo field dilution is allowed!! (2357.2.A)

& Bill of Lading

Effect of Diesel on Penetration

• How much diesel does it take to fail?

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• CSS1-h or CSS-1

• Undiluted, or

• Diluted 70/30 (70% emulsion to 30% water)

• Use Proper Size Nozzles

• Apply a uniform tack coat, 100% coverage. (compare to a brown or black sheet of construction paper) (2357.3.D)

• Tack each lift when placing multiple lifts on the same day (2357.3.D)

• Sample from Distributor (2357.3.F)

Tack Details

Construction Paper

Applied Emulsion

Broken Emulsion

Sample Splitting

• The inspector must witness:

• Sampling, and

• Splitting

• The inspector must take possession of each sample after it is split.

9

9

Who’s Who?What’s What?Will We Match With Our Companion?

4 Days of Cores

Same Letters ?Mixed Up

No Confusion

Better system – ID by lot #

When do we Stop Production

• Stop Production if:

• If all the lots in a day’s production fail

• Or if greater than 50% of lots on multiple days fail

Filling the core holes

Core holes must restore the surface by 24 hours of coring.

Failure = $100/working day/lot

Workmanship

Spread all mixtures without segregation to the cross sections shown on the plans.(2360.3.B.2.a)

Paver Hopper

The need for a consistent amount of material in the paver hopper.

Cold Screed/Cold Mix

After compaction, the finished surface of each lift shall be reasonably free of segregated, open and torn sections, and shall be smooth and true to the grade and cross section shown on the plans with the following tolerances:

Must be free of segregated and open and torn section and deleterious material.Cut or saw and then remove and replace material placed outside the described limitations at no additional cost to the Department. If the Engineer determines the material can remain in place outside the limits, the Department will pay for the material at a reduced cost of $10 per sq. yd.

Paving Items

Paving Date: “Do not place asphalt pavement final wearing course lift after November 1south of an east-west line between Browns Valley and Holyoke. The Engineer may waive these restrictions when:(1) The Contractor is not placing asphalt mixture on the traveled portion of the roadway.(2) The roadway involved is closed to traffic during the following winter, or(3) The Engineer provides written direction to place the mixture.” (2360.3.A.4)

Road Conditions: “Do not place asphalt mixtures when weather or roadbed conditions or moisture conditions or the roadway surface are judged unfavorable by the Engineer. (2360.3.A.4)

Ordinary Compaction Projects: The specification does not allow paving when the air temperature is below 32°F. Table 2360-26 specifies the minimum laydown temperature as measured behind the paver for different combinations of air temperature and lift thickness. (2360.3.D.2.c)

Paver Mounted Thermal Profile (PMTP)

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Why the Technology

• Allows contractor to quickly identify poor quality and apply corrective actions where needed.

• Enhance the quality of pavement being placed.

• Colder mix or cold mix pockets in the mat generally equate to lower density.

– With all things considered, density of the pavement has one of the biggest impacts on long term performance and durability.

• Uniformity, Uniformity, Uniformity

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Thermal Segregation – End Dump Thermal Segregation

Category

Percent of Sublots

Low 0%

Moderate 0%

Severe 100%

Paver Stop (with a Pickup Machine)

7 minutePaver Stop

Cold Mix from Paver

Details

Keep an eye onthe end product

Keep rollersclose to paver

Thank you!Have a Safe and Productive Season

Greg Johnson

gregory.d.johnson@state.mn.us

651-366-5464

Deb Evans

deb.evans@state.mn.us

651-366-55742/13/2019 mndot.gov 29