OUTLINE MOTIVATION & OBJECTIVE EVOLUTION OF SPG. SEAUPG Annual Meeting Corpus Christi, TX 11/17/2016

Transcription

1 Implementation of the Surface Performance-Grade (SPG) Specification for Chip Seal Binders in Texas TxDOT Implementation Project 5-16 D. Hazlett, J. Peterson A. Epps Martin, E. Arambula, T. Freeman, S. Theeda, J. Epps SEAUPG Annual Meeting & Exhibits Corpus Christi, T November 17, 2016 Motivation & Objective Evolution of SPG Validation of SPG 2016 SPG Specification SPG Binder Selection Current Validation Industry Interaction 2017 SPG Specification Effects & Challenges of SPG Next Steps OUTLINE MOTIVATION & OBJECTIVE Increase performance and reduce cost Improve chip seal/seal coat binder spec & selection performance-related temperatures that cover entire in service range for specific climate consider aging during critical 1 st year reduce variability in grades possibly adjust due to traffic Implement SPG in T in multi-year, staged effort Replace Seal Coat Binder Tier Selection Table & Item 300 Seal Coat Binder Properties in service AC-15P AC-10-2TR AC-20-5TR SPG Composition Polymer Required? Min Polymer Content? Assurance of Modified Behavior Elastic 50F Phase T HIGH Assurance of Sprayability 205C Resistance to T HIGH T T HIGH 140F Other Consistency 77F Softening Point Resistance to Aggregate T LOW after Aging ^PAV Aging w/rtfo w/rtfo w/rtfo ^BBR T LOW ^BBR T -18C CRS-2P HFRS-2P SPG Composition Polymer Required? Minimum Polymer Content? Minimum Asphalt Content? Solubility? Assurance of Modified Behavior Elastic 50F / 39F Phase T HIGH threshold Float 140F (for HF) Assurance of Sprayability Saybolt 122F Resistance to Summer Pavement Temperature (T HIGH) DSR T HIGH 140F Other Consistency 77F Softening Point Resistance to Aggregate Cold Pavement Temperature (T LOW) after Aging PAV T HIGH EVOLUTION OF SPG TxDOT Research Project (3.5+ yrs, 45 field sections) NCHRP Research Project (2.5+ yrs, 3 field sections) TxDOT Research Project 0-16 (2 yrs, 30 field sections) SPG specification for chip seal/seal coat binders in service Method B for emulsion residue recovery SPG specification part of system to be used with design guidelines quality control procedures construction techniques BBR T T LOW Emulsion-Specific Stability Tests Demulsibility Storage Stability & Sieve 1

2 EVOLUTION OF SPG VALIDATION OF SPG Desired Performance Lab Test Performance Criteria Threshold Resistance to Bleeding Polymer Modification Resistance to Aggregate Loss T HIGH, Unaged T INT G*/sin (kpa), min , T HIGH threshold % strain, 0.8G initial * (Unaged) G initial *(MPa), max (PAV) UTI>89 or 84 UTI> Resistance to Aggregate Loss Stress Relaxation T LOW PAV S (MPa), 8 sec m value, 8 sec TxDOT Implementation Project Binders, 19 Sections built in % Lab:Field T HIGH % Lab:Field T 2yrs Freq. Sweep BBR: Poor correlation 16 Binders, 24 Sections built in % Lab:Field T HIGH 75% Lab:Field T LOW VALIDATION OF SPG with PP 72 Method B Recovery RV < C by T 316 SPG 64 SPG SPG 70 SPG Average 7 day Maximum Surface Pavement Design <64 < <70 <73 Temperature, C Minimum Surface Pavement Design Temperature, C > 25 > 13 > 16 > 19 > 22 > 25 > 13 > 16 > 19 > 22 > 25 > 16 > 19 > 22 > 25 Dynamic Shear, T315 G*/Sinδ Minimum: 0.65 kpa Test rad/s, C Phase angle (δ), T where G*/sin δ = 0.65 kpa Pressure Aging Vessel (PAV) Residue (AASHTO PP1) PAV Aging Temperature, C Creep Stiffness, T 313 S, Maximum: 500 MPa with AASHTO PP 72 Method B RV < C by T 316 SPG 70 Avg 7 day Max Surface Pvmnt T, C <70 Min Surface Pavement T, C > 13 > 16 > 19 > 22 > 25 SPG 70 <70 Method B for Emulsion Residue Recovery Thin Film on Silicone Mat 60 C for 6 hrs G*/Sinδ >0.65 kpa by T 315 Test 10rad/s, C Phase angle (δ), temp. where G*/sin δ = 0.65 kpa > 13 > 16 > 19 > 22 >

3 SPG 70 <70 PG vs. SPG T HIGH = average 7 day max 1 high T 20mm 2 T HIGH & T LOW ; 10 ⁰C for T LOW grade T HIGH = average 7 day max high T surface T HIGH & T LOW ; No 10 ⁰C for T LOW grade 1 2 PAV Residue S < 500 MPa by T 313 > 13 > 16 > 19 > 22 > DSR, HIGH (RTFO) INT (PAV) Creep Stiffness, T 313, S and m 60s No specification on RTFO aged binder & No T INT 3 Creep Stiffness, T 313, 8s; no m value 4 5 No specification on δ at T HIGH continuous T HIGH for UTI > Determine Climate Based SPG Grade by Map or Spreadsheet 2. Adjust SPG Grade for Traffic, Flexibility, & Modification 1. Determine Climate Based SPG Grade by Map or Spreadsheet SPG Climate Based Requirement Map 4. Select Final SPG Grade 3. Compare with SPG Grades of Traditional Materials 1. Determine Climate Based SPG Grade by Map or Spreadsheet Increase T HIGH for High Traffic AADT < 500 SPG < AADT < 5000 AADT > 5000 SPG Decrease T LOW for Weak Pavement Structure 2. Adjust SPG Grade for Traffic, Flexibility, & Modification Climate Based Requirement High Traffic Increase UTI >89 0 C to ensure polymer modification if desired 3

4 3. Compare with SPG Grades of Traditional Materials District Environmental Requirement ABL 19 AMA 64 25, 22 AUS 16, Traditional Binder (2013/2014) AC20 5TR: AC10 2TR: 22 AC10: Selected SPG Grade with 3C Field Performance Monitoring Visual Distress Survey Aggregate Loss Bleeding Embedment Binder & Aggregate Application Rates 4. Select Final SPG Grade BWD 19, 16 CRP 13 PAR 19 PHR 13 AC10 2TR: 22 AC15P: 70 28, CRS 2: 19 AC20 5TR: 22 AC15P: CRS 2( 22) Pre Construction Post 1 Year Time Between Material Application Weather Conditions INDUSTRY INTERACTION Technical Briefings Suppliers AGC of T TxAPA Presentations WASHTO ETF AEMA/ARRA/ISSA SEAUPG ISAET TRB INDUSTRY INTERACTION SPG Round Robin 1 Fall/Winter AC 15P & CRS 2P with & without Reheating for T HIGH, time threshold, grading T 5 suppliers + TxDOT + TTI Debriefings SPG Round Robin 2 Summer/Fall 2016 SPG Hot Applied & Emulsion 10 suppliers + TxDOT + TTI 6 0 C increments 2 T HIGH Polymer modification Elastic 50 0 F 55 0 C and 61 0 C m-value for information only AC 15P Round Robin Results Cont. Low Temp. Cont. High Temp Supplier C Supplier C Cont. G*/sin δ = 0.65 kpa Phase Angles for AC 15P Grading Temp

5 (Hot: 25) (Cold: 64 25) (Hot: 25) (Cold: 25) (Hot: 64 25) (Cold: 25) (Hot: 25) (Cold: 64 25) (Hot: 64 25) (Cold: 64 25) (Hot: 25) (Cold: 25) 25 CRS 2P Results: With & without reheating Cont. Low Temp. Cont. High Temp. (with reheating) Cont. High Temp (without reheating) Phase Angles for CRS 2P (Hot) Cont. G*/sin δ = 0.65 kpa with reheating Grading Temp Cont. G*/sin δ = 0.65 Phase Angles for CRS 2P (Cold) kpa without reheating Grading Temp ROUND ROBIN 1 RESULTS Results rounded to nearest 1 0 C due to precision & bias For both, Very Good T LOW For both, Good T HIGH with threshold & AC 15P more variable. Considering precision & bias, 3 0 C SPG increment too T HIGH. Considering precision & bias, 3 0 C SPG increment T LOW. ROUND ROBIN 1 RESULTS For practicality, 6 0 C increments T HIGH &T LOW Offset SPG temperatures (from those for PG) proposed capture statewide 0 C climate in T make SPG grades unique and fewer in number possibly decrease adjustments needed from climate based requirement No difference (within 1 0 C) in 2 procedures (with & without reheating) considering precision & bias No changes to requirement for UTI >89 proposed with majority showing no difference (within 1 0 ) between the the threshold & the grading T PHASE ANGLE DATA with PP 72 Method B Recovery RV < C by T 316 Average 7 day Maximum Surface Pavement Design Temperature, C SPG SPG 73 SPG 79 < <73 <79 Minimum Surface Pavement Design Temperature, C > 13 > 19 > 25 > 31 > 13 > 19 > 25 > 31 > 13 > 19 > 25 > 31 Dynamic Shear, T315 G*/Sinδ Minimum: 0.65 kpa Test rad/s, C Historical Data Phase angle (δ), T where G*/sin δ = 0.65 kpa Pressure Aging Vessel (PAV) Residue (AASHTO PP1) PAV Aging Temperature, C Creep Stiffness, T 313 S, Maximum: 500 MPa

6 with AASHTO PP 72 Method B Recovery RV < C by T 316 SPG 73 Avg 7 day Max Surface Pavement T, C <73 Min Surface Pavement T, C > 13 > 19 > 25 > 31 Method B for Emulsion Residue Recovery Thin Film on Silicone Mat 60 C for 6 hrs 6 C INCREMENTS OFFSET FROM PG REQUIRED FOR UTI >86 T HIGH THRESHOLD *MA FOR EMULSION RESIDUE = 84 G*/Sinδ >0.65 kpa by T 315 Test 10rad/s, C Phase angle (δ), temp. where G*/sin δ = 0.65 kpa SPG 73 <73 > 13 > 19 > 25 > * * * * w/6 0 C T HIGH & T LOW SPG 73 <73 Revised SPG Climate Based Requirement Map PAV Residue S < 500 MPa by T 313 > 13 > 19 > 25 > 31 EFFECTS of SPG Performance Related specification tied to specific climate & traffic Each material meets a grade Less variability within grades More competition Higher performing binders by current spec still higher performing binders Current Tier Selection Table to be replaced by SPG Binder Selection guidelines Retain selection of material type (hot applied or emulsion) Retain allowance for wider SPG grade with payment at narrower grade Retain season restrictions by district CHANGE New recovery procedure Requires BBR CHALLENGES of SPG Some differences between PG & SPG 6

7 NET STEPS Complete 2016 Verification 8 Binders, 15 Sections in 7 Districts Complete Round Robin 2 Continue Gathering Industry Input Resubmit to AASHTO & ASTM & Respond Document & Market with TxDOT, TTI Communications Adjust to CHANGE in Formulations Contact Amy Epps Martin, Ph.D., P.E. Professor and A.P. & Florence Wiley Faculty Fellow Zachry Department of Civil Engineering Research Engineer (TTI) 310D CE/TTI 3136 TAMU College Station, T (979) a eppsmartin@tamu.edu 7