material selection and pavement design – accelerated ......material selection and pavement design...
TRANSCRIPT
Short Course 2019 October 15, 2019
Material Selection and Pavement Design –Accelerated ConstructionS. Lacy Peters, P.E. – TxDOT Atlanta District
October 15, 2019
Short Course 2019 October 15, 2019
Table of contents
4-5
6-8
9-12
13-18
19-24
3
25-26
What is Accelerated Construction?
Accelerated Construction Guidelines – Key Points
Accelerated Construction Guidelines – Pavement Design
Accelerated Construction Guidelines – Construction Considerations
Foamed Asphalt Base Project – Cass County; FM 3129
Foamed Asphalt Base Project – Harrison County; FM 9
Questions
1
2
2
3
4
5
6
7
Short Course 2019 October 15, 2019
What is Accelerated Construction?
Accelerated construction entails all the aspects of getting a project built rapidly including project selection, planning, contracting, design, traffic control, construction methods, publicity, and contingences.
The barriers as well as the opportunities associated with accelerated construction operations include materials availability and delivery, equipment capabilities and limitations, quality control/quality assurance (QC/QA) procedures, workforce availability, economic incentives, public information, and safety considerations among others.
Accelerated Construction Guidelines – December 2017
3
Short Course 2019 October 15, 2019
Accelerated Construction Guidelines – Key Points
4
Emergency versus Planned Accelerated Construction
Guidelines for TxDOT Projects
– Project Selection and Planning
– Contracting Methods
– Design
– Contractor Selection
– Involvement of Contractor
– Construction Considerations
References
Short Course 2019 October 15, 2019
Accelerated Construction Guidelines – Key Points
5
Design
– General Considerations
– Geometric Design
– Bridge Design
– Drainage Design
– Pavement Design
– Roadside Safety Design
– Traffic Control and Job Sequencing
– Project Duration
Short Course 2019 October 15, 2019
Accelerated Construction Guidelines - Pavement Design
6
Pavement Design
– Pavement Recycling
– Stabilization of Subgrade/Base Items
– Reconstruction of Old Concrete Pavement
– Special Considerations
• Widening Projects
• Curb and Gutter Section
The number of materials that need to be placed in a pavement section should be minimized. The use of stabilized layers often reduces the number of materials that are required.
Alternatives should be evaluated from a performance and constructability point of view.
Short Course 2019 October 15, 2019
Accelerated Construction Guidelines - Pavement Design
7
Pavement Design (continued)
– This section references the Pavement Design Guide, which is now called the Pavement Manual and can be found on the MNT website.
– In place recycling avoids the removal and replacement of materials from the job site.
– The use of asphalt stabilized base materials rather than flexible base will reduce the overall thickness of the pavement layer. Asphalt base can be placed at a higher production rate than flexible base materials.
• The length of time to cure some materials prior to placing subsequent layers should be evaluated on a project-by-project basis.
– Rigid pavement reconstruction techniques: bonded concrete overlay, unbondedconcrete overlay, cracking and seating or rubblizing the existing pavement and then overlaying with ACP, or an ACP overlay of the existing concrete pavement.
Short Course 2019 October 15, 2019
Accelerated Construction Guidelines - Pavement Design
8
Pavement Design (continued)
– All the regular issues with pavement design still exist.
– The pavement design phase should take into account those materials that are needed and even those that are most likely to be utilized in your area. If there are items/sources that are not typically used, thoughts even down to the need for qualified technicians to inspect and test should be noted.
– The Pavement Manual should be consulted for material selection and design of accelerated options.
– REMEMBER: Accelerated Construction is NOT intended to Accelerate Maintenance!!!!!
Short Course 2019 October 15, 2019
Accelerated Construction Guidelines – Construction Considerations
9
Construction Considerations
– Work Plan and Work Sequence
– Workforce
– Work Space
– Equipment
– Quality Control/Quality Assurance/ Acceptance
– Information Exchange
Short Course 2019 October 15, 2019
Accelerated Construction Guidelines – Construction Considerations
10
Construction Considerations – (continued)
– Accelerated construction is not possible without a carefully crafted plan prior to construction and one that is adjusted continuously and at key intervals during the construction process.
– Decisions need to be made at the lowest workforce level on the project as possible.
– Securing right-of-way to provide space should be considered by TxDOT and made available to all contractors.
– The work plan should allow for equipment downtime for maintenance and repair.
• Redundant critical equipment should be on hand
• The development of equipment should continue so that the capabilities to move material quickly from one location to another can be improved.
Short Course 2019 October 15, 2019
Accelerated Construction Guidelines – Construction Considerations
11
Construction Considerations – (continued)
– QC/QA
• QUALITY CANNOT BE SACRIFICED ON ACCELERATED CONSTRUCTION PROJECTS!
• Decisions related to materials acceptance need to be made in a timely fashion.
• Technicians used for sampling and testing should be certified, and laboratories in which testing is performed should be accredited.
– Regularly scheduled meeting should be established at the initiation of the project. Additional meetings should be held when necessary. Key Contractor and TxDOT personnel should be expected to attend.
Short Course 2019 October 15, 2019
Accelerated Construction Guidelines – TAKE AWAY
12
QUALITY CANNOT BE SACRIFICED ON ACCELERATED CONSTRUCTION PROJECTS!
DO NOT ACCELERATE CONSTRUCTION IN A WAY THAT WILL RESULT IN ACCELERATED MAINTENANCE!!!
Short Course 2019 October 15, 2019
Asphalt Foamed Base Project – Cass County; FM 3129
13
Location Map and Typical Section
Short Course 2019 October 15, 2019
Foamed Asphalt Base Project – Cass County; FM 3129
14
Mixture Design provided by MTD
– Richard Izzo, Soils and Aggregates Section Director
– Materials and Tests Division
– (512) 506-5907
Short Course 2019 October 15, 2019
Foamed Asphalt Base Project – Cass County; FM 3129; Process
15
Short Course 2019 October 15, 2019
Foamed Asphalt Base Project – Cass County; FM 3129; TTI Evaluation
16
TTI Evaluation and Conclusions Provided by Stephen Sebesta
Short Course 2019 October 15, 2019
Foamed Asphalt Base Project – Cass County; FM 3129; TTI Evaluation
17
Conclusions included:
– Foamed asphalt base modulus on average is within the expected range of 200 – 300 ksi
– Section is holding up well to trafficking, even without the one-course, with almost no raveling
– No major items of concern at this time• SB OWP by DPS check station may be monitored; this is the zone of
highest deflection observed on the work completed to date• ~ STA 405+91 to 387+86
– Techniques to mitigate occurrences of edge instability at early trafficking appeared effective• Future projects should consider shoulder width in design stage,
particularly if heavy truck traffic must be allowed same day• Future FDR work should particularly be careful of excessive moisture at
time of treatment especially when early traffic is required
Short Course 2019 October 15, 2019
Foamed Asphalt Base Project – Cass County; FM 3129; Current Status
18
Short Course 2019 October 15, 2019
Foamed Asphalt Base Project – Harrison County; FM 9
19
Location Map and Typical Section
Short Course 2019 October 15, 2019
Foamed Asphalt Base Project – Harrison County; FM 9
20
Mixture Design provided by MTD
– Richard Izzo, Soils and Aggregates Section Director
– Materials and Tests Division
– (512) 506-5907
Short Course 2019 October 15, 2019
Foamed Asphalt Base Project – Harrison County; FM 9; Process
21
Short Course 2019 October 15, 2019
Foamed Asphalt Base Project – Harrison County; FM 9; TTI Evaluation
22
TTI Evaluation and Conclusions Provided by Stephen Sebesta
Short Course 2019 October 15, 2019
Foamed Asphalt Base Project – Harrison County; FM 9; TTI Evaluation
23
Conclusions included:
– FDR base modulus with foamed asphalt on average exceeds the assumed 150 ksi from design• AVG was 175 ksi• Current recommendation for foamed asphalt layer design is 200 ksi.
This value was not met on FM9.– The subgrade modulus AVG of ~ 13 ksi is significantly higher than the
assumed value in design. Any observed high deflections should not be caused by subgrade support.
– SB IWP was poorest result. 15% of data in SB IWP had deflections exceeding the threshold from design.
– Should monitor particularly the last 2 mi. in SB direction, and retest project in ~ 3 – 6 months.• Evaluate if the results have changed and evaluate if local adjustment to
FDR layer modulus with foamed asphalt is required.
Short Course 2019 October 15, 2019
Foamed Asphalt Base Project – Harrison County; FM 9; Current Status
24
Short Course 2019 October 15, 2019
TxDOT Districts – Atlanta
25
Dallam Sherman Hansford Ochiltree Lipscomb
Hartley Moore Roberts Hemphill
Oldham Potter Carson Gray Wheeler
Deaf Smith Randall Armstrong DonleyCollings-worth
Parmer Castro Swisher Briscoe Hall
Bailey Lamb Hale Floyd Motley
Dickens King KnoxHockleyLubbock
Crosby
GarzaLynnTerryYoakum
Gaines Dawson Borden Scurry Fisher Jones
Kent Stonewall HaskellThrock-morton
Baylor
Wilbarger Wichita
WICHITAFALLS
Clay
Archer
YoungJack
Howard Mitchell NolanTaylor
Callahan Eastland
Glasscock Sterling Coke Runnels
ReaganIrion
Cooke Grayson Fannin
Lamar
Delta
Red River
PARISBowie
Wise Denton CollinHunt Hopkins
RainsWood Upshur
Marion
Cass
Titus
Mor
ris
Camp
ATLANTA
HarrisonSmith
VanZandt
Henderson TYLER
Rusk Panola
AndersonCherokee
Freestone
DallasDALLAS
Rockwall
Palo Pinto
Parker Tarrant
Shelby
SabineHouston LUFKIN
Angelina
TylerPolk
Trinity
Jasp
er
New
ton
SanJacinto
Walker
Leon
Navarro
Ellis
Hardin
FORTWORTH
Erath
Hood Johnson
Hill
BosqueMc
LennanHamilton
Coryell
Bell
Falls
WACO
RobertsonMadison
Milam
Brazos
Grim
es
Burleson
BRYAN
WashingtonLee
Austin
FayetteHarris
Montgomery Liberty
BEAUMONT
Orange
Jefferson
ChambersHOUSTON
FortBend
Brazoria
Matagorda
Wharton
Colorado
LavacaGonzales
Dewitt
YOAKUM
Jackson
Victoria
CalhounGoliad
Bee Refugio
Karnes
LiveOak
JimWells
SanPatricio
NuecesCORPUSCHRISTI
Kleberg
Kenedy
WillacyHidalgo
BrooksJim
HoggZapata
Starr
PHARR
Duval
Webb
LAREDO
La SalleDimmit
Zavala Frio Atascosa
McMullen
Guadalupe
Wilson
Bexar
MedinaUvalde
Real Bandera
KerrKendall
Gillespie Blanco
Kinney
SANANTONIO
Edwards
Sutton Kimble
Mason LlanoBurnet
Williamson
Travis
AUSTINBastrop
Hays
CaldwellComal
Brown Comanche
BROWNWOOD
Coleman
Mills
McCulloch
San Saba Lampasas
Concho
Menard
SANANGELO
Schleicher
TomGreen
Andrews Martin
Midland
Pecos
Ector
CraneWard
WinklerLoving
Crockett
Val Verde
Upton
Terrell
ReevesCulberson
Jeff Davis
BrewsterPresidio
Hudspeth
El PasoEL PASO
ODESSA
LUBBOCK
AMARILLO
ABILENE
Cottle Foard
CHILDRESS
Fran
klin
Cameron
Short Course 2019 October 15, 2019
Questions
S. Lacy Peters, P.E. Materials and Pavement Engineer
Texas Department of Transportation Atlanta District
[email protected] 903-799-1330
26