Introduction to Asphalt Pavement Construction and Compaction For ODOT District 3 presented by

Introduction to the FQCS Program FQCS Program Governed by ODOT Specification – Applies to All Asphalt Paving Projects Administered Under ODOT Specification – May Apply to Local Governments Which Utilize ODOT Specifications – May Apply to Engineering Consultants Serving as the Independent Quality Firm (IQF) on ODOT Design/Build Projects

Introduction to the FQCS Program Specification Requirements - Item 403: – Requires the Contractor Provide a “Field Quality Control Supervisor, Holding Supplement 1041 Field Quality Control Supervisor Approval and Who is a Company Employee, Who is Routinely and Usually at the Paving Site During Placement of Any Non-Temporary Asphalt Concrete Pavement”

Introduction to the FQCS Program How the FQCS Program Seeks to Meet ODOT’s Objectives: – Places responsibility for field quality control on the contractor – not the inspector – The FQCS is to be knowledgeable in construction specifications, Manual of Procedures and understand the intent of each – The FQCS is charged with the responsibility to alter operations to bring asphalt concrete construction into conformity with specification requirements

Asphalt Concrete Construction

Goals of Flexible Pavement Design and Construction: Structure - Provide a structure that has adequate strength to distribute the wheel loads to the soil without undue deflection, compaction or consolidation. Surface - Provide a surface that is adequately stable so as to not deform under traffic load, is weather resistant, has adequate skid resistance, is adequately smooth and is sufficiently wear resistant.

Goals of Flexible Pavement Design and Construction: Are accomplished through Proper structural (thickness) design for the existing soil and anticipated loads. Optimum number of layers to facilitate stability, smoothness and economy Selection of the appropriate mix types for each of the layers to achieve stability, smoothness and economy Construction that complies with or exceeds the specifications for uniformity, smoothness and compaction(QC/QA and FQCS)

Introduction to the (FQCS) Program Pavement Design Manual, Section 400 contains instructions on thickness design, proper mix applications and layer build-ups. (last updated Jan. 20, 2012)

Requirements for Compaction, Compaction is the greatest determining factor in dense graded pavement performance. Inadequate compaction results in pavement with decreased strength, reduced fatigue life, accelerated aging, decreased durability, and a greater tendency toward rutting, raveling, and moisture damage.

Asphalt Concrete Compaction Objectives of compaction: Increase stability smooth the surface increase density and reduce air voids * * thereby making the mix impermeable to air and water, which are the environmental elements, in the presence of UV light, which breakdown asphalt mixtures

Density is so critical that it is now commonly specified and measured by agencies and used as the basis of paying for hot mix asphalt. ODOT, Table A pay factors, density between 92 % and 96 % (of TMD) for 100 % pay, higher or lower density receives a deduction or in extreme must be replaced and S 1055 Deductions for less than 92% TMD

Factors affecting compaction Mix properties aggregates, gradation, crushed or smooth binder grade, temperature-viscosity curve Ambient cooling conditions: air and pavement temperatures wind chill solar heating Temperature of the mix at placement, WMA or HMA Thickness of the mat – min 2xNMAS, Opt. is 3-4X Types of rollers, number of roller passes may need to be adjusted based on all these construction factors

Binder Properties affecting compaction At 300 degrees F--- a lubricating fluid At 150 degrees F--- an adhesive Therefore: compaction must be accomplished while the binder (asphalt) is above 175 Degrees F (85 C)

Time for Compaction

2 Breakdown Rollers Close to Paver

Equipment for Compaction types of rollers and capacities steel wheel rollers: 3 wheel, static tandem, vibratory (vary amplitude with thickness and frequency to achieve at least 10 impacts per foot) pneumatic (rubber) tired for base and variable thickness courses Rollers may require ballast for specified weight

Compaction ( ) Tandem Vibratory or Static and Rubber Tire Rollers

Compaction Procedures Three stages of rolling: breakdown, first passes behind the paver, make mix stable enough to compact intermediate, obtain optimum density finish, smooth out roller marks complete all rolling before mat reaches 175 deg. F Establish and maintain a consistent rolling pattern that achieves the required density

Rolling Pattern Speed & lap pattern for each roller No. of passes for each roller Min. temperature by which each roller must complete pattern (above 175 F) IMPORTANT: Paver speed must not exceed that of the compaction operation

Compaction Procedures What roller coverage is required to obtain optimum density? Three methods: use ODOT spec capacities ( and ) to determine number and type of rollers required – keep them rolling in a consistent pattern (form CA-FP-4) run a test strip and measure relative density with density gage, and S 1055 to establish the rolling pattern and number of passes (Form Appendix E- S 1055) density acceptance (locate cores per TE 217)

(page 189 of the handbook)

Compaction Specification requirements for compaction of 448 are contained in and , 2013 CMS pages and , P Compaction of 446, Density Acceptance, and 880, Warranty, Pavements are more at the discretion of the contractor. Discussion of compaction inspection is contained in the 2013 MOP under , page 416, and under , page 437 and , page 503. For updated compaction requirements on 448, see the latest revision of S 1055, dated 4/18/2014 and the applicable release of SS 800.

2013 CMS , Rollers, and , Compaction , page 179 CMS, “Immediately after spreading, compact the mat uniformly using rollers that comply with tables ,2,3, Page 176, for types and capacities of rollers”

Other Requirements of Coordinate the spreading of the mixture with the required roller coverage, considering the rate of cooling of the mixture as affected by lift thickness and weather conditions. Complete compaction during the period of time in which the temperature is sufficient for the roller coverage to be effective in compacting the mixture. PaveCool program

Other Requirements of A three wheel roller is required in the breakdown position for intermediate and surface courses not using 446 or 448 density measurement. If vibratory rollers are used, they must be supplemented with three wheel rollers or pneumatic tired rollers.

Other Requirements of Cold longitudinal joints on intermediate or surface courses must be compacted with a three wheel roller. Don’ t use vibratory rollers on courses less than 1 and ½ inches thick. Type 1 (large) pneumatic tired rollers combined with steel wheel rollers are required on 301 and 302 base courses. Pneumatic tired rollers are required on variable depth courses. Pneumatic tired rollers are not recommended for polymer asphalt concrete, because of excessive material pick-up on the tires and may be prohibited if they leave deformation.

Item Density and Acceptance The 2013 CMS includes provisions for Density measurement and acceptance on certain 448 projects. See and.05 and S 1055 Density will be measured using nuclear or electromagnetic gauges calibrated to cores.

Item 448 Acceptance ElectromagneticNuclear Procedure: S The contractor has an option whether to use nuclear or PQI gauge.

Item 448 Acceptance Requirements: S on the project Field Quality Control Supervisor (FQCS) Sets Expectations and Communication methods Copy of Supplemental Specification 1055 Gauge and gauge operator  Nuclear Gauge meeting ASTM D 2950 calibrated within two years  Or Pavement quality indicator (PQI) Model 300

Density and Acceptance Changes in the specifications governing coring and 446 acceptance have been adopted for Changes are found in SS 800, and in and include: A. - samples including cores must be taken and handled by personnel holding an ODOT approval, either asphalt technician level 2, 3 or FQCS G. -The taking, handling and testing of cores must be documented and saved.

has been revised in SS 800 The Engineer is to tell the contractor the method to be used to determine random core locations at the beginning of the project. Use of the electronic form TE-217 is recommended in the Manual of Procedures. See the ODOT website at gt/Admin/Inspection%20Forms/TE- 217%20for%20446%20Cores%20-%20Electronic.xls gt/Admin/Inspection%20Forms/TE- 217%20for%20446%20Cores%20-%20Electronic.xls

TE217

has been revised in SS 800 Each lot (> 400t/d) shall have " cores. The engineer will sub-divide each lot into 5 sublots and designate 2 cores from each sub-lot. 7 cores shall be taken at locations > 12" from a cold longitudinal joint. 3 cores, 1 each from the 1st, last and one intermediate sub-lot, shall be taken 4 " from a cold longitudinal joint, either confined or un- confined. (different for wedge joints) Notify the engineer if locations given do not conform to this requirement.

Core Locations per

has been revised in SS 800 Sister cores for the contractor's QC may be taken longitudinally from and within 4" of the random core. The contractor is not to take and save additional cores. 3 additional cores may be taken from the first lot of a JMF for correlation of density gauges. Any other cores to be taken must be done as documented in the approved QCP. All cores taken must be documented, tested and destroyed after testing.

has been revised in SS 800 There are to be no loose extra cores at the paving site, either on trucks, equipment or persons. Any loose cores or unmarked cores can be taken and destroyed by ODOT. In addition, failure to follow these requirements may justify an investigation and possible loss of contractor personnel approval. See the “Core Procedure” discussion in the MoP under beginning on page 499

Asphalt Concrete Compaction SUMMARY YOU MUST ADEQUATELY COMPACT HMA Get the Proper Air Voids in the Mix (4%-8% air voids = 92%-96% MTD) Compact while the MIX is HOT Understand the factors that affect compaction! ROLL THE MIX QUICKLY AND THOROUGHLY WITH PROPER EQUIPMENT TEST FOR DENSITY

Other issues in asphalt concrete construction Mat uniformity Longitudinal joint construction Tack coat placement

Questions? About: Asphalt Concrete Construction and Compaction Requirements