CoreLok was first introduced in 1998 to measure Bulk Specific Gravity of Open Graded Friction Course (OGFC)

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1 Asphalt Density Measurement System CoreLok History CoreLok was first introduced in 1998 to measure Bulk Specific Gravity of Open Graded Friction Course (OGFC) Airviods > 7-8% Industry needed a quick and accurate method for testing OGFCs CoreLok became an accepted method for Bulk Density testing in 2002 InstroTek developed other uses for CoreLok 2000 and 2001 Maximum Specific Gravity Aggregate Specific Gravity Porosity Measurement 1

2 CoreLok Advantages Versatile Established Product Easy to Use Fast and Accurate Versatile CoreLok performs 4 different test in asphalt laboratories Bulk Specific gravity (Gmb) Bulk Specific gravity (Gmb) Maximum Specific gravity (Gmm) Fine and coarse aggregate density & absorption Porosity 2

3 Established Product Over 50 papers and studies published worldwide 2,500 units sold worldwide Over 2,000 units sold in United States Accepted Testing Method in America for over 10 years Primarily used for QC/QA Testing Used by Universities, State and Local Government Agencies and U.S. Federal Government Federal Highway Administration (FHWA) ASTM and AASHTO Specifications Bulk - ASTM D AASHTO T-331 Max - ASTM D Apparent Aggregate ASTM D7330M CoreLok Studies 3

4 Easy to Use Set up and installation of the CoreLok can be done in 1 ½ hours or less Training for the CoreLok can be done in half a day CoreLok test only takes a few steps to perform Technician follows process established by InstroTek Results calculated longhand or with Gravity Suite software Yearly Maintenance No calibration needed Yearly verification of vacuum systemstem Fast and Accurate Asphalt test with CoreLok can be performed in 5-10 minutes Aggregate test only take 25 minutes Traditional T-84 can take up to 1 day Soaking time is 19.5 hours No technical judgments required CoreLok results are highly repeatable between operators and laboratories CoreLok meets precision standards established by: National Institute of Standards and Testing (NIST) AASHTO 4

5 Before CoreLok Traditional Bulk Specific Gravity Dimensional Method Parafilm Wax Paraffin Wax Saturated Surface Dry (SSD) Current Standard Test in America Traditional Maximum Specific Gravity Vibrating Table & Picnometer Traditional laggregate Gravity Cone & Temp Traditional Bulk Specific Gravity Dimensional Gmb Use of dimensional measurements to determine asphalt core volume and density Core is not a perfect cylinder Does not account for surface voids Underestimates Density In summary, the mensuration method will measure the sample volume by: Including surface texture Including surface-connected void Including all interior void, and so Will always return the highest air void content. 5

6 Traditional Bulk Specific Gravity Parafilm & Paraffin Wax Sample preparation can take up to 1 hour Destroys asphalt core Core cannot be retested Results dependent on technician Wax can be messy and may cause harm to technician Parafilm can underestimate densities Paraffin wax can overestimate densities Traditional Bulk Specific Gravity Saturated Surface Dry (SSD) Widely accepted method in USA Easy to perform No equipment needed Results depend on technician Not considered accurate for asphalt samples over 8% airvoids In summary, the SSD method will measure the sample volume by: excluding surface texture excluding surface-connected void including interconnected interior void, and so will always return the lowest air void content. Overestimate density 6

7 CoreLok Compared to Traditional Bulk Test Methods Professor, Dr. Filippo Practico, DIMET Department, Mediterranca University, Italy AirVoid Content Comparison (Dim. / SSD / CoreLok) 35 Air Void Content (%) SSD CoreLok Mensuration 5 0 Samples arranged in ascending air void content 7

8 Maximum Specific Gravity CoreLok Max Gravity Alternative to the conventional Rice Test for determining maximum specific gravity of loose asphalt mix Limited exposure to water, eliminates lengthy dry-back time Predetermined vacuum settings do not change no variability between tests High percent AC samples are not subject to self compaction Completed CoreLok Rice Test in 7-10 minutes Traditional Aggregate Gravity AASHTO T 84 and ASTM C 128: Specific Gravity and Absorption of Fine Aggregate p gg g 8

9 Traditional Aggregate Gravity Technical judgment required Requires very skilled technician to perform test t Test is difficult reproduce due to the subjective nature of the SSD condition Test can take up to 3 days From sample preparation to final dry weight determination Aggregate Gravity CoreLok AggPlus System Results are not dependent on the technician Results are not dependent on the technician Works with fine, coarse, and combined aggregates Takes only minutes to perform test Accurate, precise and repeatable Automatic calculations and results through AggSpec software 9

10 CoreLok Porosity Test Porosity is the measure of the interconnected airvoids in an asphalt samples Direct correlation to Permeability Important for the development of porous asphalt Treats water runoff Increases traction when wet Reduces groundwater pollution Extends the life of paved area in cold climates CoreLok Advantages Versatile CoreLok Performs 4 different test Established Product Many years in service all around the world Easy to Use Installation and training is simple and fast Fast and Accurate Tests are very fast and process is accurate 10

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