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Slurry/Micro Mix Design Procedure. Project Videoconference September 15, 2005. Videoconference Outline. Roll Call and Introductions-Holland Project Goals, Objectives, Timeline- Moulthrop Phase III – Design Validation & Training Activities-Moulthrop/Seeds
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Slurry/Micro Mix Design Procedure Project Videoconference September 15, 2005
Videoconference Outline • Roll Call and Introductions-Holland • Project Goals, Objectives, Timeline- Moulthrop • Phase III – Design Validation & Training Activities-Moulthrop/Seeds • Phase II - Improved Mix Design Activities -Holleran • Wrap Up including next meeting- Holland • Q/A session-Holland
Introduction to Project • Goals • Develop, Analyze, and Validate an improved mix design procedure for slurry surfacings • Objectives/Tasks • Phase 1-Literature review and work plan development • Phase 2-Laboratory phase • Phase 3-Field validation, Guidelines, and Specifications
Videoconference Goals • Goals • Discuss the selection of trial projects for 2006 construction season • Selection guidelines • Discuss the current Phase II work
Phase III Activities • Project Selection Guidelines • Candidate Field Sites • Construction and monitoring of sites • Specifications • Reference Manual
Need sites NOW • Construction is planned for 2006 • Funding of sites needs to be secured in advance • Fugro needs to be involved with site selection
Project Selection - Step 1 The States are responsible for the following activities: • Nomination of test sites • Construction of test sections • Provision of traffic control for all test site data collection • Reporting as-built construction data • Reporting structural information (cross section thickness/material) • Reporting maintenance activities • Reporting friction resistance if available
Project Selection - Step 2 • Development of experimental plans and design • Coordination among participating agencies • Final acceptance of nominated test sites • Development of uniform data collection guidelines and forms • Coordination of material sampling and testing • Monitoring pavement performance • Data analysis and reporting • Review of material mix designs and construction plans The Research Team is responsible for:
Site Selection Guidelines • Variables to consider • Traffic • Climate • Pavement Surface and condition • Geometry • Length • Section Layout
Site Selection Guidelines • Traffic • Two levels-high and moderate • High->25,000 ADT (>10 million ESALs) • Moderate->10,000 <25,000 ADT (4-10 million ESALs over 20 years w/ 10% trucks
Site Selection Guidelines • Climate • Four LTPP regions • Wet Freeze • Wet No-Freeze • Dry Freeze • Dry No-Freeze
Site Selection Guidelines • Climate Goal-Projects in each region
Site Selection Guidelines • Pavement Surface • Bituminous Concrete (HMA) • Portland Cement Concrete (PCC) • Provided the agency permits placement of bituminous products on PCC pavements
Pavement Surface Climatic Region Traffic Level Project Name Asphalt Concrete Region 1 Moderate Project 1 Project 2 High Project 3 Project 4 Region 2 Moderate Project 5 Project 6 High Project 7 Project 8 Portland Cement Region 1 Moderate Project 9 Concrete Project 10 High Project 11 Project 12 Region 2 Moderate Project 13 Project 14 High Project 15 Project 16 Example Project Nomination Factorial
Desired Characteristics • Adequate Length • To accommodate the number and length of test sections • Uniform Traffic • As much as possible • Pavement Geometry • Horizontal curves =/< 3° • Vertical grades =/< 4%
Site Selection Guidelines • Pavement Conditions • Little distress, but uniform (raveling, bleeding, transverse cracks) • Rutting > 1” unacceptable • Ride quality - < 100”/mile • No moisture damage • 5 years remaining service life • FWD testing if available-SCI < 20 at 9k lbs. load
Recommended Pilot Project Layout • 152-m (500-ft) section placed using the ISSA (International Slurry Surfacing Association) mix design procedure • 152-m (500-ft) control section, with no treatment • 152-m (500-ft) section placed using the Slurry Systems Mix Design (SSMD) developed in this project • Second 152-m (500-ft) ISSA section • Second 152-m (500-ft) control section • Second 152-m (500-ft) SSMD section Transition zones of 30 m (100 ft) lengths (minimum) are used before and after each section
Key Training Deliverables • 1.5-Day Training Course • Reference Manual • Visual Aids • Instructors Guide • Pre-Job Training Module
Phase III – Remaining Work • Training – Complete 1.5-day Training Course materials and Pre-Job Module
Phase II Progress Report • Subtasks • Develop and Evaluate new or improved test procedures • Analyze the results of the test methods • Prepare test protocols • Conduct ruggedness testing of equipment
Laboratory Phase Outline • Testing Philosophy • What do existing tests tell us? • Proposed New Tests
Philosophy Of Approach • Performance Related Tests • Address Failure Modes • Simulate Field Conditions • Measures Cohesion, Adhesion and Abrasion Resistance • Stages to be evaluated • Mixing • Setting and Curing • Long Term Performance • Tests that can be used for all slurry systems and to evaluate mix variables
New Mix Design Procedure • Will it Mix? • Will it set? • Will it Perform? Properties through the stages of the mixture’s life are the key!
Drawbacks of the Current System • Technology and reproducibility of tests • Limited data set (aggregates and binders) • Inability to simulate road conditions • Inability to address various traffic conditions
New Mix Design Procedure • Materials Selection • Create Matrix of Mix Proportions • Measure Short Term Constructability • Select Optimum binder properties • Measure Long Term Performance • Iterative process- feedback controlled • Evaluate finished product using field control tests
Aggregate Tests • Sieve Analysis • Sand Equivalent • Abrasion Resistance by Los Angeles Abrasion • Sulfate Soundness • Micro- Deval test for field abrasion performance
Emulsion and Binder Tests • Tests on original emulsion • Recovered binder tests • Ring and Ball Softening Point, Penetration • Potential use of DSR, BBR,DTT –beyond the scope of project but AEMA is pursuing
New Mixture Tests • Mixing Test • developed in Germany • Setting and Curing • new development • Abrasion/Cohesion Test • developed in France
New Mix Test • Allows selection and initial ratios of components • Allows examination of effects of different components and additives • Relates to initial constructability • Measures mix stiffness and effect of mix conditions • Provides the answer to ”will it mix and will it spread?”
Outputs - Mixing and Workability 12.0 12.0 9.0 9.0 Kg-cm Kg-cm time time Stabilized - quick set Micro - fast set
New Setting and Curing Test • Measures cohesion build Up • Used to estimate traffic time • Provides an estimate of resistance to early traffic • Evaluates the impact of environmental conditions and physical effects such as compaction
Setting and Curing Test Setup Clamping Pressure 200Kpa Clamping Pressure 200Kpa Motorized gear shifts shaft through 180 Motorized gear shifts shaft through 180 . . Allows precise Allows precise º º application of twisting torque to measure resistance to shear application of twisting torque to measure resistance to shear force. force. Torque measurement taken at base close to interface. This Torque measurement taken at base close to interface. This will prevent bending in the shaft to influence results. will prevent bending in the shaft to influence results. Electronic torque (strain gauge) measurement will transmit Electronic torque (strain gauge) measurement will transmit to PC for display. to PC for display. PC will display spread sheet to include torque PC will display spread sheet to include torque time graph and calculation of peak torque. time graph and calculation of peak torque. Interface of foot with sample Interface of foot with sample — — this is this is rubber. Part of the process will use rubber. Part of the process will use different surface types on the foot to different surface types on the foot to improve grip and reproducibility. improve grip and reproducibility.
Curing Test Results Will It Set ? Will it take Early traffic? % Emulsion
Constructability - Short Term Performance Test (CAT) • A form of cohesion test (French WTAT) • Can be performed on both curing and cured samples • Allows simulation of field conditions and physical effects such as compaction • Wheel WTAT at different cure and soak times
New CAT Test • Rise in Cohesion measured for different mixes under different curing conditions • Uses full mix gradation • Can be performed under water
CAT Output Poor Moderate High
CAT Process Non Cohesive Non Cohesive
Progress to Date • Mixes selected have been characterized by existing ISSA Technical Bulletins • Component materials have been characterized • Preliminary testing on wet cohesion and sample conditioning methods has been done • Equipment has been procured, designed and constructed • Preliminary testing and modifications have been made
Progress to Date (cont.) • CAT-formerly French WTAT final procedure established • Thicker samples are produced with the entire aggregate gradation • Mix test equipment programmed and operational • Classification of mixes based on mixing torque developed • Mixing bowl and stirrer geometry established • Micro Deval equipment procured • Continuing problems with procuring equipment for the setting and curing test
Phase II Remaining work • Complete the testing matrix of slurry system mixtures • Finalize mix design procedure • Prepare test protocols • Conduct ruggedness testing • Finalize field tests • Prepare summary report
Catch up plan • Issues to accelerate lab work • Increase labor • Philosophy used on real projects • Equipment • Work will be accomplished by 12-05 • Mix Designs for field trials to be done by 1 March 2006
Phase II Deliverables • Improved mix design procedures and performance tests • Field test equipment & procedures • Field Validation of mix design procedure
Project Summary • Phase I is complete • Phase II is behind schedule, but plans have been made to complete work by Dec 05 • Phase III is underway, but we need candidates for field projects • Pilot projects are to be constructed in 2006 so they have at least one year to be monitored for performance