Oh No, We Got an Airport Job! Contractor Quality Control. Investment in Staff, Labs and Equipment. We ve Come A Long Way.

Transcription

1 Contractor Quality Control Oh No, We Got an Airport Job! John Savastio Quality Control Manager Highway Materials, Inc. We ve Come A Long Way. Investment in Staff, Labs and Equipment Acceptance based on asphalt content / gradation, air voids Method based spec. Implementation of Quality Systems Quality Control Quality Assurance vs. Testing frequencies Lines of communication Equipment maintenance Calibrations Proficiency programs Quality Assurance makes sure you are doing the right things, the right way. Quality Control makes sure the results of what you've done are what you expected. 1

2 Development of the JMF Meet Specified Properties Start by targeting mid-spec. Utilize resources effectively: mutual fund approach Maximize plant production and efficiency Laboratory Design vs. Plant Production Design vs. production Capability of the Plant Gradation Variation Hot Bins Stockpile Degradation Volumetric Properties JMF to Optimize Compaction JMF to Prevent Segregation Stability Correct Amount of Asphalt Substantial Roller Effort Effect of Natural Sand- Rounded Particles Workability Low / High #200 Excess Coarse Aggregate What Are the Requirements? Section 100 FAA Advisory Circular Contractor Quality Control Program Complete project quality control requirements Broad based requirements Section 401 FAA Specifications Item P-401 Plant Mix Bituminous Pavements Detailed quality control requirements for HMA (P401) production and testing (Section 401-6) Section 100 Requirements QC Program Intent Provide production of acceptable quality materials Provide information to assure specification can be met Allow Contractor latitude to develop own standard of control 2

3 Section 100 Before the Project Begins.. Program Description Explain to us (the owner; State, City, County or Private Owner) what you (Mr. Contractor) are going to do to provide us with an acceptable project that conforms to all plans and specifications AND PUT IT IN WRITING!! JMF s submitted at least 14 days in advance QC Plan submitted for review at least 14 days in advance Components of QC Plan Quality Control Organization Quality Control Organization Project Progress Schedule Submittals Schedule Inspection Requirements QC Testing Plan Documentation of Activities Corrective Action Adam Amspacher Plant Tech QC Organization for Lancaster Airport Southeast Apron Improvements John Savastio QC Manager Richard Sonnon Sr. QC Tech David Roman Project Manager Don Neil Paving Manager Jerrod Willow Paving Foreman Raymond Gonzalez Field Tech Enough QC Techs to get the Job done at Plant & Field Quality Control Organization Program Administrator Professional Engineer w/1 year experience Engineer-in-Training w/ 2 years experience BS Civil Engineering/Technology/Construction w/ 3years experience NICET Level III (Materials/Construction) NICET Certified w/ 5 years experience Quality Control Organization Program Administrator Duties Institute and implement the Quality Control Program Review work performed and all documentation Assist in corrective actions when required 3

4 Quality Control Organization Quality Control s Engineers Engineering s Experienced Craftsman Certifications Equivalent to NICET Level II Minimum of 2 years experience in area of expertise Quality Control Organization Quality Control Duties Inspect all materials, construction, plant and equipment for conformance to the specifications Perform all quality control testing required by the specifications and quality control plan Assure all materials meet specifications and follow corrective action guidelines when materials do not meet requirements Inspection Requirements Section QC Plan Field Operation Quality Control Tests Density readings and cores results Inspection of equipment used for placing, finishing & compaction Plant Operation Quality of Aggregate Verify aggregate production/delivery Mix Control Verify blending/proportioning Plant Equipment Inspect thermocouples, scales, asphalt delivery & mixing chamber Item Description Test type Standard Frequency Responsibility Control Requirements Test Performed Stockpile/Col d Feed Gradation Aggregate Moistures Hot Bin Gradation Asphalt Content Mixture Gradation Mixture Moisture Mixture Temperature s Fines Specific Gravity Density Monitoring Quality Control Testing Chart - Per Lot Basis P401 1" Max Test Test Method Performed By Frequency ASTM C 136 Agg 1 / Week ASTM C / Day / HMA ASTM C 566 Aggregate ASTM C 136 HMA 2 / Lot ASTM C 117 HMA PTM / Lot ASTM C 136 HMA 2 / Lot ASTM C 117 HMA ASTM D / Lot HMA Dial Type & 4 / Lot & Infrared Gun Plant Operator Agg AASHTO T-84 1 / Week Breakdown & Field ASTM D 2950 Intermediate, every 300ft Spec Limits P401, Section 6.5 P401 Section 6.5 P401, Section 6.5 P401, Section 4.8 Per JMF ±0.030 of JMF Target 99% of Lab Density Section Documentation The contractor is required to maintain current (daily) quality control records These records must show all inspections results to include conforming and defective or deficient work Must be legible and signed by the Program Administrator Section Documentation Daily Inspection Reports Factual Evidence of continuous QC Inspection Technical specification item # and description Compliance with approved submittals Proper storage of materials and equipment Proper operation of all equipment Adherence to plans and technical specs Review of quality control tests Safety inspections 4

5 Section Documentation Daily Test Reports Review of QC Tests Technical specification # Test designation Location Date of test Control requirements Test results Causes for rejection Recommended corrective action Retests QC Plan- Corrective Action Section 100 Surveillance by the Engineer All operations, production, manufacture, shipment or placement, are subject to surveillance by the Engineer Surveillance by the Engineer does not relieve the Contractor or performing quality control inspections Section 100 Noncompliance The Engineer will notify the Contractor of noncompliance material at which time the Contractor shall immediately take corrective actions Where quality control activities do not comply The Contractor may be required to replace unqualified work or personnel The contractor may be ordered to stop work Section Pre-pave Meeting Pre-Test Mix Contractor Producer Owner Consultant engineer Assurance Testing Laboratory Verify mix properties at the plant (gradation, asphalt content, air voids, VMA) and make adjustments if necessary. Test results should be as close to target as possible. 5

6 Pre-Test Mix Construct Test Strip Verifying field properties (workability, ease of compaction, density) is as essential as verifying the mixture properties. Try to place over an area with similar conditions. 300 x 25 ft, 2 passes Longitudinal joint 3 Random Samples Plant Mix Field Cores - Density 2 Attempts prior to removal at Contractor s expense. Test Section Criteria Air Voids Stability & flow Mat & Joint density PWL of 90+ Gradation and Asphalt content Action limits VMA Section 401 Contractor QC Any Quality Quality Control should never have to experience more than 5 projects in a lifetime. Section 401 Contractor QC Testing Laboratory Joint Use by Contractor and Engineer Engineer has priority use of necessary equipment Minimum of 150 ft 2 with a ceiling height of 7.5feet Adequate lighting Equipment properly maintained Asphalt Content Twice per lot Gradation Twice per lot Plant QC Requirements 6

7 Section 7.1: Asphalt Content Appendix C Extraction Test Extraction ASTM D 2172 Ignition ASTM D 6307 Nuclear method ASTM D 4125 Section 7.2: Gradation Analysis Appendix C Gradation Analysis Gradation Cold Feed Composite Hot Bins Belt Composite Sample These provide support for controlling the process in addition to the HMA mixture gradations Section 7.2.4: Aggregate Moisture Section 7.3: Temperatures Aggregate moisture Once per lot Mix moisture Once per lot <0.5% Temperature 4X per lot Bitumen in Storage Tank Mixture in Trucks Dryer Temp. Mixture at Job Site 7

8 Appendix C Temperature Control Charts Visual mechanism to assist in differentiating between Chance causes (inherent) of variability Assignable causes (process) of variability Prevents Tampering Control Charts Action & Suspension Limits Gradation & AC Action & Suspension Individual measurement Range measurement Action ½ = +/- 6% 3/8 = +/- 6% #4 = +/- 6% #16 = +/- 5% #50 = +/- 3% #200 = +/- 2% A/C = +/- 0.45% Suspension ½ = +/- 9% 3/8 = +/- 9% #4 = +/- 9% #16 = +/- 7.5% #50 = +/- 4.5% #200 = +/- 3% A/C = +/- 0.70% Suspension Limits 1/2 = 11% 3/8 = 11% #4 = 11% #16 = 9% #50 = 6% #200 = 3.5% A/C = 0.8% Based on n=2 Range Limits The Range Suspension Limits can be increased if the Contractor performs more than 2 tests per lot. x 1.18 for n=3 x 1.27 for n=4 The process is considered to be out of control when: One point falls outside the Suspension Limit (Ind. or Range) Two points fall outside the Action Limit for Individual measurement 8

9 Gyratory Compactor as QC Tool Real Time Air Voids Imitates field compaction more accurately Greater sample size Measures height to the mm Correlation: Wt./Ht. Ratio vs. Voids Monitor Assurance Testing Partnership Consistency Sampling Calibration Test Standards Random Sampling Sampling of Mixture Preparation of Specimens Maximum Theoretical Specific Gravity Specimen Bulk Specific Gravity Field Quality Control Hauling Equipment Field Quality Control Density specification on Joints and Mat Thickness and Smoothness 9

10 Paving Equipment Performance Rolling Equipment Stringline Paver Requirements Automated Controls Stringline 30ft Ski Ski-Type Device High VPM, Lowest Possible Amplitude Communication Constant Monitoring Game Plan Production goal Gmb- 100% Constant monitoring Nuke gauge technician Roller operators Paving foreman Plant Trans Tech PQI Humboldt 5001-C Troxler 4640B Core #4 Trouble-shooting Density Insufficient Rollers or Rolling Effort Paver Speed Inconsistent Effort Mix Design 10

11 Rolling in Echelon Bad Joints Good Joints Coring Sufficient Material + Mat 99% Gmb = 100PWL on Joints Asphalt Core Rigs Make sure they can be and are level Use new core bits Make sure there is ample supply of water Do not remove the cores with a screw driver Use a core removal device Core Saw Use a saw that provides a clean straight cut Cores Core Saw 11

12 Transportation of Cores Core Testing Discuss method utilized with Engineer and testing representative Dry back via fans or oven Destructive testing or non-destructive testing Monitor the Assurance (Acceptance) Testing Contractor Quality Control I would rather deal in preventative medicine than handle autopsies! 12