Stabilized Base IC Demonstration US 84, Wayne County, MS Mississippi State Department of Transportation Experimental Plan

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1 Plac e your mes sage here. F or maximum i mpact, us e t wo or thr ee sent ences. Accelerated Implementation of Intelligent Compaction Technology for Embankment Subgrade Soils, Aggregate Base, and Asphalt Pavement Materials Stabilized Base IC Demonstration US 84, Wayne County, MS Mississippi State Department of Transportation Experimental Plan

2 1. Report No. FHWA-IF Title and Subtitle 2. Government Accession No. N/A 3 Recipient Catalog No. N/A 5. Report Date Accelerated Implementation Of Intelligent Compaction Technology For Embankment Subgrade Soils, Aggregate Base, And Asphalt Pavement Materials - Experiment Plan for the MSDOT Stabilized Soil IC Demonstration 7. Author(s) George Chang, Qinwu Xu, Dave Merritt of the Transtec group; David White of Iowa State University, and Bob Horan of Asphalt Institute. 9. Performing Organization Name and Address The Transtec Group, Inc Balcones Drive Austin TX Sponsoring Agency Name and Address Federal Highway Administration Office of Pavement Technology, HIPT New Jersey Avenue, SE Washington, DC Supplementary Notes May Performing Organization Code N/A 8. Performing Organization Report No. N/A 10. Work Unit No. (TRAIS) N/A 11. Contract or Grant No. DTFH61-07-C-R Type of Report and Period Covered Draft 14. Sponsoring Agency Code N/A Contracting Officer s Technical Representative: Victor (Lee) Gallivan 16. Abstract Intelligent compaction (IC) is an emerging technology, and for some applications it is mature enough for implementation for field compaction of pavement materials. The intent of this project is to realize the blueprint in the FHWA IC strategic plan. This study was initiated under the Transportation Pooled Fund (TPF) Solicitation No. 954, which includes 12 participating state department of transportation (DOTs): Georgia, Indiana, Kansas, Maryland, Minnesota, Mississippi, North Dakota, New York, Pennsylvania, Texas, and Virginia, and Wisconsin. This document is to provide a detailed site-specific experiment plan for the MSDOT stabilized base IC field demonstration. 17. Key words Compaction, intelligent compaction, roller, soils, subgrade, embankment, cement treated, pavement performance. 18. Distribution Statement No restrictions. This document is available to the public through the National Technical Information Service, Springfield, Virginia Security Classif. (of this report) Unclassified 20. Security Classif. (of this page) Unclassified 21. No. of Pages 22. Price Form DOT F (8-72) Reproduction of completed page authorized (art. 5/94) i

3 SI* (MODERN METRIC) CONVERSION FACTORS APPROXIMATE CONVERSIONS TO SI UNITS Symbol When You Know Multiply By To Find Symbol LENGTH in inches 25.4 millimeters mm ft feet meters m yd yards meters m mi miles 1.61 kilometers km AREA in 2 square inches square millimeters mm 2 ft 2 square feet square meters m 2 yd 2 square yard square meters m 2 ac acres hectares ha mi 2 square miles 2.59 square kilometers km 2 VOLUME fl oz fluid ounces milliliters ml gal gallons liters L ft 3 cubic feet cubic meters m 3 yd 3 cubic yards cubic meters m 3 NOTE: volumes greater than 1000 L shall be shown in m 3 MASS oz ounces grams g lb pounds kilograms kg T short tons (2000 lb) megagrams (or "metric ton") Mg (or "t") TEMPERATURE (exact degrees) o F Fahrenheit 5 (F-32)/9 Celsius or (F-32)/1.8 ILLUMINATION fc foot-candles lux lx fl foot-lamberts candela/m 2 cd/m 2 FORCE and PRESSURE or STRESS lbf poundforce 4.45 newtons N lbf/in 2 poundforce per square inch 6.89 kilopascals kpa APPROXIMATE CONVERSIONS FROM SI UNITS Symbol When You Know Multiply By To Find Symbol LENGTH mm millimeters inches in m meters 3.28 feet ft m meters 1.09 yards yd km kilometers miles mi AREA mm 2 square millimeters square inches in 2 m 2 square meters square feet ft 2 m 2 square meters square yards yd 2 ha hectares 2.47 acres ac km 2 square kilometers square miles mi 2 VOLUME ml milliliters fluid ounces fl oz L liters gallons gal m 3 cubic meters cubic feet ft 3 m 3 cubic meters cubic yards yd 3 MASS g grams ounces oz kg kilograms pounds lb Mg (or "t") megagrams (or "metric ton") short tons (2000 lb) T TEMPERATURE (exact degrees) o C Celsius 1.8C+32 Fahrenheit ILLUMINATION lx lux foot-candles fc cd/m 2 candela/m foot-lamberts fl FORCE and PRESSURE or STRESS N newtons poundforce lbf kpa kilopascals poundforce per square inch lbf/in 2 *SI is the symbol for th International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380. e (Revised March 2003) ii o C o F

4 TABLE OF CONTENTS Introduction 1 Goals 2 Timeline and Test Site Description... 2 Timeline of Activities... 2 Test Site US Soil Cement Properties of Test Site US MSDOT Compaction Acceptance Criteria... 5 Description of the Selected IC Rollers... 6 Caterpillar Single Drum Padfoot IC Roller System... 6 Overall System Description... 6 Measurement Value... 8 Feedback Control... 9 Documentation System Case/Ammann Single Drum IC Roller System Overall System Description Measurement Value Feedback Control Documentation System Logistics 17 Team Members and Responsibilities Schedule and Details of Field Demonstration Activities Roller and GPS Setup Initial Training Correlation Tests Mapping Existing Layer Production Compaction Preliminary Analysis and Report Open House Data Analysis and Reporting Deliverables 25 Anticipated Benefits Appendix A. Interview and Sample Questions Interview Strategy iii

5 Reason for interview process? Who to interview? When to interview? Sample Questions - Contractor s Roller Operator (if applicable) Initial Interview (beginning or early in ICPF project) Final interview (end of ICPF project) Appendix B. ISU Intelligent Construction Geo-Mobile Lab iv

6 LIST OF TABLES Table 1. Summarized features of Caterpillar single drum IC rollers Table 2. Summary of features of the Case/Ammann single smooth drum IC Roller Table 3. Team Members for the MSDOT IC Demonstration Project Table 4. Test schedule and machine settings for the soil IC demonstration LIST OF FIGURES Figure 1. Current test schedule of the ICPF field demonstrations Figure 2. Map of the test site (US 84)... 3 Figure 3. Site plan for the project site (US 84)... 4 Figure 4. Density-moisture curve of MSDOT 9C materials Figure 5. Caterpillar single drum padfoot IC roller Figure 6. Caterpillar single drum IC System Figure 7. CMV values for various compacted materials Figure 8. Caterpillar pod style vibratory system Figure 9. Caterpillar vibratory system adjustment of amplitude Figure 10. Caterpillar IC CD700 onboard documentation system Figure 11. Caterpillar IC AccuGrade Office software Figure 12. Case/Ammann single smooth drum IC roller Figure 13. Case/Ammann IC system Figure 14. Ammann Compaction Expert-Plus (ACEplus) system Figure 15. Lumped parameter two-degree-of-freedom spring dashpot model representing vibratory compactor and soil behavior (reproduced from Yoo and Selig 1980) Figure 16. Case/Ammann k s stiffness measurement system Figure 17. Case/Ammann auto feedback system Figure 18. Case/Ammann auto adjustment of vibration frequency and amplitude Figure 19. Case/Ammann optimization of compaction using auto feedback system Figure 20. Case/Ammann ACEplus report system Figure 21. Comparison of IC measurement influence depth compared to traditional in situ spot test measurements Figure 22. Schematic diagram for calibration tests Figure 23. IC measurement values for successive lifts of aggregate base over subgrade, showing hard and soft areas reflecting through the surface compaction layer v

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8 Introduction The intelligent compaction (IC) field demonstrations are a major part of the FHWA Transportation Pooled Fund (TPF) research project effort, Accelerated Implementation of Intelligent Compaction Technology for Embankment Subgrade Soils, Aggregate Base, and Asphalt Pavement Materials. The IC field demonstrations are anticipated to be conducted in each of the 12 participating state departments of transportation (DOTs), including: Georgia, Indiana, Kansas, Maryland, Minnesota, Mississippi, North Dakota, New York, Pennsylvania, Texas, Virginia, and Wisconsin between 2008 and To facilitate this project, a Technical Working Group (TWG) was formed to include the FHWA Contracting Officer s Technical Representative (COTR) and IC-associated team members, IC project team, IC facilitator, IC pooled fund State representatives, and IC roller vendor representatives. The IC project team and IC facilitator are referred to collectively as ICPF team. ND MN WI NY KS IN PA MD VA TX MS GA Figure 1. Current test schedule of the ICPF field demonstrations. The purpose of this site-specific and roller-specific experimental plan is to provide details of the soil IC field demonstration to be conducted in May 2009 (tentatively) for the Mississippi State Department of Transportation (MSDOT). Key attributes for this field demonstration will be on-site training, comparison of IC roller technologies to traditional compaction equipment and practices, correlating IC roller measurements to in-situ spot test measurements, mapping two or more layers of compacted material to understand the influence of underlying layer support, selecting the appropriate machine operation parameters (e.g., speed, amplitude, frequency, etc.), and managing and analyzing the IC and in-situ test data. This document includes: specific goals of this demonstration project, timelines and test site description, description of the selected rollers, logistics, schedule and details of field demonstration activities, and data analysis and reporting. 1

9 Goals The goals of this demonstration project are to: Demonstrate IC technology to MSDOT personnel, contractors, and the highway community at large, Help MSDOT accelerate the development of IC quality control (QC) specifications for subgrade soils (cement treated granular material) materials, Develop an experienced and knowledgeable IC expertise base within MSDOT, and Identify and prioritize needed improvements and research for IC equipment. The research team also has additional goals to move forward the IC technologies: Document impact of variable feedback control on compaction uniformity Document machine vibration amplitude influence on compaction efficiency Study IC roller measurement influence depth Develop correlations b/w IC roller values to traditional measurements Compare IC results to tradition compaction operations Study IC roller measurement values in production compaction operations, and Evaluate IC measurement values in terms of alternative specification options The primary focus material is stabilized granular base material. The objectives of this demonstration project are short-term goals for introducing IC technology to MSDOT and contractors who may not have prior experience with IC, in order to demonstrate the benefits of IC for improving the compaction process by achieving more uniform density/modulus of the subbase and subgrade materials and providing roller operators (and superintendents) better feedback tools to make right decisions, and ultimately real-time quality control. Timeline and Test Site Description Timeline of Activities The demonstration site and materials of interest were selected during a planning meeting between MSDOT, paving contractor, and the ICPF Team on January 14, The field IC demonstration will tentatively be conducted during week of June 1, The material of interest is Type V stabilized base material. Test Site US 84 2

10 The IC demonstration site is located at US 84 in Wayne county, MS (see Figure 2). This project is a 4- mile long new asphalt construction with two lanes in each traffic direction. The top 6 in. of granular (sandy) base will be treated with 5% cement as the MSDOT 9C chemically treated granular material. (see Figure 3) Figure 2. Map of the test site (US 84) 3

11 Figure 3. Site plan for the project site (US 84) Soil Cement Properties of Test Site US 84 The MSDOT 9C material has the following properties: PI = 10, LL = 30, Gradation: (percent passing): #10 = 100%, #40 = 20 to 100%, #60 = 15 to 85%, and #200 = 6 to 40% The base material is stabilized with 5% (by volume) cement. As seen in one of the lab density-moisture curves, the optimum density of the stabilized material is 1,979 kg/m3 at moisture of 10.9%. 4

12 Density (kg/m^3) Moisture (%) Figure 4. Density-moisture curve of MSDOT 9C materials. MSDOT Compaction Acceptance Criteria The acceptance of the MSDOT 9C material is specified in MSDOT Special Provision No M (08/14/2007). The lot will be divided into five approximately equal sub-lots with one density test taken at random in each sublot. The average of the 5 density tests shall equal or exceed 97.0% with no single density test below 95.0%. Sublots with a density below 95.0% shall be corrected at no additional cost to the State and retested for acceptance. Each lot of work found not to meet the density requirement of 97.0% of maximum density, may remain in place with a reduction in payment as set out in a table as specified in MSDOT specification. 5

13 Description of the Selected IC Rollers The Caterpillar pad foot single drum IC roller and the Case/Ammann pad foot single drum roller are selected for this demonstration project. All the above IC rollers are equipped with a global position system (GPS), a roller response measurement system, and a document system. Caterpillar Single Drum Padfoot IC Roller System Overall System Description The features of selected Caterpillar padfoot IC roller (Figure 5) are detailed in Table 1. Figure 5. Caterpillar single drum padfoot IC roller. 6

14 Table 1. Summarized features of Caterpillar single drum IC rollers. Manufacturer/ Vendor Model Model Number Drum Size Machine Weight Amplitude Settings Frequency Setting/ Range Auto-Feedback With measurement System Measurement Value Measurement Unit Documentation System Caterpillar AccuGrade CS-683E (to be update) 60 dia. X 84 wide 40,785 lbs. (~ 20.5 tons) High: 0.070, Low: ,800 vpm No, but there is a feedback via RMV. Yes CMV, MDP Unitless AccuGrade Office The Caterpillar IC system can be illustrated in Figure 6 (though it shows a smooth drum roller). The Caterpillar IC system include an accelerometer, slope sensor, controllers, communication data radio, Real-time Kinematic (RTK) GPS receiver, an off-board GPS base station (not shown in Figure 6), and onboard report system. The slope (angle) sensor measures the left/right tilt of the drum to a range of ±45. Collectively, the above components are integrated into so-called Caterpillar AccuGrade system to provide accurate IC measurements during compaction. Radio GPS Receiver Display Controllers Slope Sensor Accelerometer (Courtesy of Caterpillar) Figure 6. Caterpillar single drum IC System. 7

15 Measurement Value The Caterpillar IC measurement values for indication of levels of compaction include compaction meter values (CMV), resonance meter values (RMV), and machine drive power (MDP). The CMV was developed by Geodynamic in 1970 s. CMV is defined as a scaled ratio of the second harmonic vs. the first harmonic of the drum vertical acceleration amplitudes based on a spectral analysis. The scaling is made so that CMV values could cover a range of 150. The CMV is reported as average values within two cycles of vibration or typically 0.5 seconds. The resulting CMV (Figure 7) is a dimensionless, relative value requiring constant roller parameters such as drum diameter, linear load, frequency, amplitude, speed, and etc. Since the CMV is an integral with contribution from large depths (3 to 6 ft for Caterpillar IC rollers) with the highest weighting of the layers closest to the surface, caution should be taken when comparing CMV to the top layer compaction level (often measured by other in-situ devices such as nuclear gauges or LWD) only. Soft material Slightly harder material Hard material S A S A S A 0,5F F 2F fq 0,5F F 2F fq 0,5F F 2F fq CMV (Courtesy of Caterpillar) Figure 7. CMV values for various compacted materials. The RMV is similar to CMV except it is computed as a scaled ratio of the 0.5 harmonic vs. the first harmonic of the drum vertical acceleration amplitudes based on a spectral analysis. The RMV is an indicator for the degree of double jumps (explained in the following Feedback Control section) of the roller. The MDP, on the other hand, is based on the rolling resistance of the drums to determine the forces acting on the drum and the desired energy to counteract the forces. MDP is a related value indicating a compacted material is either above or below a well-compacted counterpart or a calibration surface. The Caterpillar IC sensors would compensate for machine grade, acceleration, and speed in computation of MDP values. 8

16 Feedback Control The Caterpillar IC does not have an automatic feedback system. However, roller operators can make use of the measured CMV, RMV, and roller vibration frequencies to determine the adjustment of drum vibration amplitudes (see Figure 8 and Figure 9) required to obtain compaction while preventing the roller from double jumping. Double jumping is a phenomenon when the drum rebounds from a vibratory impact and bounces high to allow the next vibration to occur while the drum is still in the air. The undesired effects of double jumping include damage to the roller as well as damaging/de-compact the compacted material. (Courtesy of Caterpillar) Figure 8. Caterpillar pod style vibratory system. (Courtesy of Caterpillar) Figure 9. Caterpillar vibratory system adjustment of amplitude. 9

17 Documentation System The Caterpillar IC documentation system starts with an onboard CD700 In-cab three dimensional (3D) Display (see Figure 10). The display is equipped with keypad that allows the operator to interface with the system using push buttons and a color monitor. The operator can then view real-time information, such as machine location and speed, drum amplitude, vibration frequency, and number of passes, relative to the design plan. This system uses 3D design files that are stored on a compact flash data card and inserted into a slot next to the keypad. The compact flash card can then used to transfer data to another computer for further analysis using the AccuGrade Office software (Figure 11). AccuGrade Office is by far the most advanced IC software that allows the user to import 3D design data, convert data for use on machines equipped with AccuGrade GPS/ATS, validate the data and then export data to AccuGrade machines using a PC compact flashcard. (Courtesy of Caterpillar) Figure 10. Caterpillar IC CD700 onboard documentation system. (Courtesy of Caterpillar) Figure 11. Caterpillar IC AccuGrade Office software. 10

18 Case/Ammann Single Drum IC Roller System Overall System Description The features of selected Case/Ammann single smooth drum IC roller (Figure 5) are detailed in Table 1. Figure 12. Case/Ammann single smooth drum IC roller. Table 2. Summary of features of the Case/Ammann single smooth drum IC Roller. Manufacturers/Vendors Case/Ammann Model Name Ammann Compaction Expert-Plus (ACEplus) Model Number SV212 Drum Width 86 Machine Weight 16,000 lbs (~ 8 ton) Amplitude Settings 0 to 0.08 Frequency Settings 1380 to 2100 vpm Auto-Feedback Y (both frequency and amplitude) Measurement System ACE Measurement Value Ks - Ground bearing capacity Measurement Unit MN/m Documentation System ACEplus 11

19 The Case/Ammann IC system can be illustrated in Figure 13 with the ACE and feedback drum system. Figure 13. Case/Ammann IC system. The screen of the Ammann Compaction Expert-Plus (ACEplus) system is illustrated in Figure 14. The ACEplus system was formed by combining the former Ammann Compaction Expert (ACE) measurement and control system with continuous compaction control (CCC). (Courtesy of Case/Ammann) Figure 14. Ammann Compaction Expert-Plus (ACEplus) system. Measurement Value The roller-integrated stiffness (k s ) measurement system on the Case/Ammann IC rollers was introduced by Ammann during late 1990 s considering a lumped parameter two-degree-of-freedom spring-massdashpot system (Anderegg 1998). The spring-mass-dashpot model has been found effective in representing the drum-ground interaction behavior (Yoo and Selig 1980) (see Figure 15). The drum 12

20 inertia force and eccentric force time histories are determined from drum acceleration and eccentric position (neglecting frame inertia). The drum displacement z d is determined by double integrating the measured peak drum accelerations. The soil stiffness k s is determined using Equation 1 when there is no loss of contact between drum and soil (Anderegg and Kaufmann 2004). 2 2 mr e ecos( φ) ks = 4π f md + a where f is the excitation frequency (Hz), m d is the drum mass (kg), m e r e is the eccentric moment of the unbalanced mass (kg m), ϕ is the phase angle (degrees), a is vibration amplitude (mm). The k s value represents a quasi-static stiffness value and is independent of the excitation frequency between 25 to 40 Hz. Figure 16 illustrates the Case/Ammann k s (noted also in k B in literature) measurement system. The k s measurement system has the capability to perform compaction in a manual mode (i.e., using constant amplitude setting) and in an automatic feedback control (AFC) mode. z f m f Equivalent frame weight k susp c susp Suspension stiffness and damping z d f e (t) m d Drum weight and dynamic force generated k s c s Soil stiffness and damping F s Figure 15. Lumped parameter two-degree-of-freedom spring dashpot model representing vibratory compactor and soil behavior (reproduced from Yoo and Selig 1980). 13

21 Satellite GPS reference point Stiffness k B none 10 MN/m Roller Stiffness k B : 70 MN/m 140 MN/m (Courtesy of Case/Ammann) Figure 16. Case/Ammann k s stiffness measurement system. Feedback Control Ammann Compaction Expert (ACE) is an electronic measuring and controlling system for vibrating rollers. It is an automatic close-loop control (Figure 17) automatically adjusts roller vibratory amplitudes and frequencies (Figure 18) to suit the characteristic of the compacted ground condition. 14

22 Display & Operation Excitation A Excentricity % Control Unit Electronic Device f f opt. Differential Gear Box Hydraulic Pump Valve Exciter Position Drum Acceleration Phase Angle Sensors Accelerationsensor Rotationsensor Automatic Closed-Loop Control (Courtesy of Case/Ammann) Figure 17. Case/Ammann auto feedback system. 1-Amplitude-Machine Continuously changement of the amplitude Frequency Amplitude Speed Automatically Controlled Roller Parameter Contact force (Courtesy of Case/Ammann) Figure 18. Case/Ammann auto adjustment of vibration frequency and amplitude. As see in Figure 19, the Case/Ammann ACE auto feedback system can adjust the roller vibratory frequency and amplitude at each roller pass depending on the condition of the compacted ground condition thus, optimize the compaction with least desirable number of passes. 15

23 Compaction/Soil Stiffness Compaction Depth Number of Passes/Time (Courtesy of Case/Ammann) Figure 19. Case/Ammann optimization of compaction using auto feedback system. Documentation System Examples of screenshots of the ACEplus report system is illustrated in Figure 20. With positioning information and a graphical representation of the measurement data, ACEplus enables a fast, simple and sure interpretation of the compaction work performed. (Courtesy of Case/Ammann) Figure 20. Case/Ammann ACEplus report system. 16

24 Logistics Team Members and Responsibilities The primary parties that will be involved with planning and conducting the demonstration projects will be the ICPF project team, MSDOT personnel, the roller manufacturers, and the paving contractor. The ICPF project team for this demonstration includes Lee Gallivan, George Chang, Qinwu Xu, Dave Merritt, Bob Horan, and David White. Mr. Horan is the main coordinator of this demonstration. Dr. Chang and Dr. White are main contacts of the research team during the demonstration. Mr. Randy Battey, Mr. James Williams, and Mr. Scott White are the main contacts for MSDOT. The contractor s contact is Mr. Rick Cory. The contact information of the team members are listed below: 17

25 Table 3. Team Members for the MSDOT IC Demonstration Project Last name First name Affiliation Telephone ICPF Project Team Chang George Transtec Group, Inc (main contact) C gkchang@thetranstecgroup.com Horan Bob Asphalt Institute C bhoran@asphaltinstitute.org Xu Qinwu Transtec Group, Inc qinwu@thetranstecgroup.com Merritt Dave Transtec Group, Inc dmerritt@thetranstecgroup.com White David ISU C djwhite@iastate.edu Gieselman Heath ISU Geotechnical Mobile Lab C Gallivan Lee FHWA Victor.Gallivan@fhwa.dot.gov Cribb Mike FHWA michael.cribb@fhwa.dot.gov MacDonald Douglas FHWA douglas.macdonald@fhwa.dot.gov State DOT Battey Randy MSDOT Head Quarter (MO Materials) Williams James MSDOT Head Quarter (MO Geotech) White Scott Region 5, Materials Engineer C randyb@mdot.state.ms.us jwilliams@mdot.state.ms.us scwhite@mdot.state.ms.us Roller Vendors Rakowski Stan Sakai C s-rakowski@sakaiamerica.com House David Sakai distributor Stribling Equipment DHouse@striblingequipment.com Oetken Nick Caterpillar oetken_nick_a@cat.com Holland Bill Caterpillar distributor Puckett Machinery Bill.holland@puckettmachinery.com Carpenter Kirby Case/Ammann kcarpenter@texanamachinery.com Paving Contractors Croy Rick Dunn Roadbuilders rcroy@dunnroadbuilders.com A separate field summary sheets will be updated and distributed during the demonstration. While all the parties will work together and coordinate efforts, each will have primary responsibility for different aspects of the project both in the planning phase and during the actual project, as delineated below. ICPF Project Team Responsibilities: Coordination among all parties, Assisting in the project selection, Scheduling and arrangements for IC roller, 18

26 Coordination with IC roller manufacturers and other equipment suppliers, Assisting with correlation testing, Data collection/management, Cost of agreed upon fees associated with mobilization of IC roller, and Cost of ISU geotechnical mobile lab. State DOT (MSDOT) Responsibilities: Project selection (with assistance from the project team), Project contractual arrangements (if required), Coordination with contractors, Providing storage locations for IC rollers, Providing test equipment and manpower for in-situ testing (using standard equipment and practices for acceptance, but possibly at a higher frequency than normal), Providing or coordinating traffic control (when necessary), Facilitating the Open House, and Project delta costs for contractors. Roller Manufacturer Responsibilities: Coordinating with the project team, MSDOT, and contractor concerning shipping the IC roller in a timely manner, Providing the project team a copy of their software to view the information obtained from their IC roller, Arranging for necessary GPS base station setup, Training the operator, DOT representative, and project team on proper roller operation, Participating in the roller demonstrations in a limited capacity, and Providing technical support in a timely manner throughout the project (e.g., via phone) including equipment maintenance and repair, if needed. Paving/Earthwork Contractor Responsibilities: Coordination of paving/rolling activities and cooperation with the above parties during the course of field demonstration, and Providing conventional roller operation for the control sections. 19

27 One special provision specification by MSDOT, Section 308 Portland Cement Treated Courses was provided to contractor as a part of the paving contract. Schedule and Details of Field Demonstration Activities The stabilized base IC demonstration project will be scheduled for a 5 to 6 consecutive day period. A summary of day-to-day activities for this field demonstration is described in Table 4. Table 4. Test schedule and machine settings for the soil IC demonstration. Date TB Machine Amp (mm) Spot Tests Notes/Comments ISU arrives at site to setup mobile lab (7 am) Meet with Contractor and identify potential test areas (7am) 6 Stabilized Base (5% cement) 6/1 Setup CASE/CAT/SAKAI rollers and make trial runs with GPS (8 am) ~8 Embankment/Subgrade Collect material samples for on-site laboratory characterization (10 am) 2 1 6/1 1 CAT (padfoot) Static, 0.9, 1.8 DCP, LWD, NG, and PLT 8 m x 60 m calibration test area. 1.Prepare then compact foundation layer with 8 roller passes and map for untreated subgrade. 2.Place one 200 to 300 mm loose lift of untreated subgrade. 3.Create variable moisture conditions. 4.Compact in three lanes using static, medium, and high 8-12 passes + 3 mapping passes 5.Develop compaction curves 6.Repeat compaction for 3 lifts in same area 2 Case (smooth) TBD DCP, LWD, NG, PLT, FWD Roller mapping in production areas of (1) untreated and (2) stabilized subgrade. Monitor existing practice and perform in-situ tests for comparison. Use data for test run on IC QC/QA specification. 6/2 to 6/3 3 Case (smooth) Low, High, Feedback control 4 CAT (padfoot) Static, 0.9, 1.8 DCP, LWD, NG, PLT DCP, LWD, NG, PLT 12 m x 60 m calibration test area. 1.Compact foundation layer with 8 roller passes and map. 2.Place 150 mm lift of stabilized subgrade 3.Create variable moisture conditions. 4.Compact in three lanes using low, high, and feedback 8-12 passes + 3 mapping passes 5.Develop compaction curves 6/3 to 6/5 5/6 Case (smooth)/cat (padfoot) TBD DCP, LWD, NG, PLT, FWD 6/4 Open House presentation of preliminary results and roller demonstrations. Notes: A. Moisture condition calibration test strip areas ± 1.5% optimum except as noted. B. MSDOT assistance requested for FWD testing and information on project QA testing requirements. C. As time permits repeatability passes for roller will be performed on embankment and aggregate base. Roller mapping in production areas of (1) untreated and (2) stabilized subgrade. Monitor existing practice and perform insitu tests for comparison. Use data for test run on IC QA specification. During the field demonstration, the following tasks will be conducted: 1. Roller and GPS Setup 20

28 2. Initial Training 3. Correlation Test 4. Mapping of Existing Layer 5. Production Compaction 6. Preliminary Analysis and Report 7. Open House Roller and GPS Setup While the setup and correlation of the roller will be necessary in all cases, the basic steps in the correlation will vary depending on the capabilities of the specific IC roller to be used on the project. A GPS base station will be established on the project and the contractor must demonstrate that the mapping is working properly, is accurate, and can be used to identify a designated spot on the pavement surface within 4 inches before work can progress. Detailed field notes will be taken during the course of the demonstration project. Since each IC system is unique, the project team will require IC data to be submitted in a standard format. The data submission process will require exporting data from the roller vendor field program and post processing, if necessary, with a naming convention specified by the project team. (data requirements and data format definition is described in a separate document.) Initial Training Initial training will consist of on-site hands-on training with IC machine and GPS system setup, conducting reproducibility testing with the IC machine for varying operating conditions, managing and analyzing the data, performing in-situ testing in a timely and effective manner, and establishing a plan for comparing results to tradition compaction. The State DOT lead and ICPF project team lead will also brief all parties on the plan and answer any questions about roles and responsibilities. The roller manufacturer s representative will be available at this meeting to discuss roller operation and capabilities. The roller manufacturer s representative will be responsible for providing training for the designated roller operator(s). The initial training will take place before any field operation and accommodate 1 to 2 DOT personnel and 1 to 2 contractor personnel at each site. Selective aspects of the field demonstration will be video recorded to document the project and contribute to future presentation/technology transfer tools. Correlation Tests Since the IC rollers have drum measuring systems, correlation tests will be conducted in order to compare in-situ measurements or coring (when mandated by States) of the material being compacted with the drum measurement values from the IC system. The test locations will need to be tied with the corresponding IC roller MVs using GPS. 21

29 The recommended correlation tests are: Falling weight deflectometer (FWD) Light Weight Deflectometer (LWD) Dynamic Cone Penetrometer (DCP) Nuclear density gauges Moisture test However, it is particularly important to stress that when interpreting IC data as the measurement influence depth normally exceeds the compaction layer thickness, as demonstrated in Figure 21. Therefore, caution should be taken when correlate the results from the above correlation test results with the IC measurement values. Area over witch the roller MV s are averaged In-situ spot test measurements X 2.1 m X X X X X X X Impact Force From Rollers Distance = Roller travel in 0.5 sec. 300 mm φ LWD/FWD 200 mm φ LWD Nuclear Density Gauge Dynamic Cone Penetrometer 2.1 m 0.3 m 0.2 m 0.3 m 1.0 m 2.1 m Influence depths are assumed ~ 1 x B (width) Figure 21. Comparison of IC measurement influence depth compared to traditional in situ spot test measurements. The schematic of the calibration strips is illustrated in Figure 22 where the areas of calibration strips will be selected based on IC-Map from pass one. The in-situ measurement data will be compiled in a standard format (specified by the project team) to facilitate correlation analysis with the IC data. 22

30 Calibration Areas Production Area s of (1) untreated and (2) stabilized subgrade IC - MVs IC-TV QA-TV γ d & E LWD +2% -0% -2% w opt 6 m 3 m Subgrade calibration strip ~ 60 m for Calibration areas and up to 300 m for Production areas Full Pavement Width ( ~8 to 12 m) Figure 22. Schematic diagram for calibration tests. Mapping Existing Layer Results from IC compaction are best interpreted with knowledge of the underlying layer support conditions. Figure 23 shows IC measurements for a base layer overlying a variable support layer. Hard and soft underlying conditions tend to reflect through the upper layers affecting surface compaction. This aspect has not been addressed very well in IC specifications and in interpreting IC measurements to date. The same tandem drum vibratory roller with a measurement system can be used for mapping of existing in-place layers. 23

31 Subsurface Layer (1) Final Layer (2) Region of soft subsurface layer condition reflecting through surface compaction layer ~ 200 ft E VIB Hard subsurface layer reflecting through surface compaction layer ~ 40 ft ~ 40 ft (courtesy of Dr. David White) Figure 23. IC measurement values for successive lifts of aggregate base over subgrade, showing hard and soft areas reflecting through the surface compaction layer. Production Compaction Production compaction, including IC and conventional compaction, will follow patterns established in a specific plan for soil/embankment IC. Final data submission (exported IC data from the IC vendors field programs with appropriate post processing, compiled spot test data associated with both the IC and conventional compaction) will comply with the data requirements specified by the IC project team. Near the end of the demonstration project, an evaluation (including an interview with the roller operator) will be conducted to judge any differences in the effectiveness and efficiency of the compaction operation. The results of the evaluation and interview will be published as part of the project report. Preliminary Analysis and Report IC roller data and other associated in-situ testing data will be managed, analyzed, and issued in a concise summary report for each demonstration project. One of the challenging aspects of implementing IC technologies is learning to use the manufacturer s software, extracting the data from the machine, organizing data files, filtering the data to evaluate selected areas, analyzing the data to develop correlations and comparisons to in-situ spot measurements, and documenting the roller operations. As such, a significant effort will occur daily to download and process the results. Projects will not be successful without daily analysis of the data to learn about compaction quality and factors affecting the IC measurement values. By analyzing the data daily, changes in operations can be made to optimize the process. Therefore, standardized formats for both IC data and in-situ measurement data are crucial to make the analysis and report process successful. 24

32 Open House MSDOT will conduct an Open House for this demonstration. Tentatively, it will include a 1.5-hr indoor presentation followed by a site visit. See the field summary sheets for the most updated information. Data Analysis and Reporting The final report will be produced by refining the preliminary analysis and report approximately three weeks after the completion of the field demonstration. The report will include the following elements: Executive Summary of field operations and conditions, Test methods employed during the demonstration, Laboratory material classification and compaction characteristics, Analysis of the IC measurements (color-coded maps, probability density distribution, semivariogram, etc.), Correlation analyses, Effectiveness of the IC technology to meet the MSDOT specification, Efficiency of the operations, comparison to traditional compaction operations, Summary of feedback/interviews from contractor and MSDOT personnel, and Conclusions that relate to the overall goals/objectives of the study. All detailed data and analysis results will be included in appendixes. A final draft report will be distributed to all TWG members within 30 days after the completion of the field demonstration. Deliverables Deliverables from the demonstration projects will include the following: Project report with summary of project conditions, specifications, material classification and compaction characteristics, IC measurements values, in-situ spot test measurements, correlation analysis, production compaction analysis, and conclusions. Digital documentary from each demonstration project with photos and video of field operations and selected interviews. Updated website with project results. Anticipated Benefits Pavement Designers can use the knowledge gained from this project to improve pavement designs to minimize both initial and life-cycle costs due to reduced variability of compaction of the constructed pavement layers. QC/QA Personnel will be able to use IC data to increase the amount of available information related to the quality of construction and possibly reduce the amount of conventional QA testing. 25

33 Contractors can optimize their construction practice and QC processes to better achieve compliance with compaction specifications. Materials Suppliers can integrate the results from this study into their materials selection and proportioning procedures. Specification Developers can determine what variables should be controlled to optimize construction quality and long-term performance, thus minimizing life-cycle costs. 26

34 Appendix A. Interview and Sample Questions Interview Strategy Reason for interview process? Interviews will be conducted to capture the experiences, impressions and suggestions of key project personnel concerning the use of Intelligent Compaction to improve the compaction process and for use as a Quality Assurance/ Quality Control tool. A series of standard questions will be asked during each ICPF project. The interviews will be conducted on all ICPF projects and the interview results and important comments will be captured in project, annual and final reports. The interviews will be used to improve the process of planning, training and conducting the ICPF projects. In addition, the interviews will allow the research team to do a better job of developing specifications and making recommendations for the next steps in the study and implementation of IC technology in the United States. Who to interview? The interviews will be conducted with a minimum of four key personnel from the roller manufacturer, the state DOT and the paving contractor. The interviewers (those conducting the interviews) will be members of the ICPF research team that are on-site. The interviewees will be as follows: The ICPF state DOT representative The state DOT project manager or other field personnel The lead person for the roller manufacturer The contractor s roller operator (if applicable) A representative of the contractor s management personnel (paving foreman, project manager) When to interview? Interviews will generally be conducted before and after the ICPF project. Some of the interview questions will be the same and some will be different for before and after interviews. The interview questions may vary somewhat different depending on the person being interviewed due to that persons roles and perspectives. 27

35 Sample Questions - Contractor s Roller Operator (if applicable) Initial Interview (beginning or early in ICPF project) 1. What is your name and who do you work for? 2. Please describe your experience as a roller operator? 3. Briefly describe your role in the process of placing the pavement material? 4. What are the biggest challenges that you face as a roller operator? 5. What do you know or have you heard about intelligent compaction, if any? 6. How do you think IC can improve your effectiveness as a roller operator, if any? 7. What type of training and how long was the training you received on the IC roller? Final interview (end of ICPF project) 1. How long did you work with the IC roller on this project? 2. What features of the IC roller (other than just standard features) did you use on this project? e.g. colorcoded mapping display, roller pattern mapping, temperature mapping, roller measurement value mapping, displays of RMV, temperature reading from thermal gauge, etc. 3. What was your general impression of the IC roller and its ability to make you job easier? In what way? 4. Please rate the amount of improvement that IC technology, as you experienced it on this project, can have on making your job easier.: 1. Large improvement 2. Some improvement 3. No difference 4. Made my job harder 5. What was your general impression of the IC roller s capability to improve the compaction process? In what way? 6. Please rate the amount of improvement that IC technology, as you experienced it on this project, can have on the compaction process: 1. Large improvement 2. Some improvement 3. No difference 4. Worse than conventional compaction 7. In your opinion, was the initial training you received adequate to allow you to operate and effectively use the IC technology? 8. What suggestions do you have to improve the training the roller operator is given? 9. If given the opportunity, would you prefer to use a roller equipped with IC technology or a standard roller with no IC technology in the future? 10. Any final thoughts / suggestions? 28

36 Appendix B. ISU Intelligent Construction Geo-Mobile Lab Capabilities GPS rover and base station, satellite communication, video projector and conference room, water, diesel power plant, clime control, weather station, four wheel mule truck, 10,000 lb reaction for plate load tests, hydraulic tube sampler, and video camera with wireless microphone. Additional Testing Equipment Soils/Aggregate Laboratory: Automated Standard/modified Proctor, Resilient Modulus, Vibratory Compaction, Static Compaction, Kneading Compaction, grain-size distribution, index properties Field: Light weight deflectometers (LWD), dynamic cone penetrometers (DCP), nuclear density gauge, (NG), drive core, sand cone, Shelby tube sampler and hydraulic pusher, static/repetitive plate load test(plt) 29

37 Contact Information Victor (Lee) Gallivan, P.E. FHWA Indiana Division 575 N. Pennsylvania St., Indianapolis, IN (317) George Chang, P.E., PhD The Transtec Group, Inc 6111 Balcones Dr. Austin, TX (512) Fax (512) Report Prepared by : George Chang, P.E., PhD Qinwu Xu Dave Merritt, P.E. The Transtec Group, Inc. David White, PhD Iowa State University Bob Horan, P.E. Asphalt Institute