Status of the first experiment at the PaveLab Fabricio Leiva-Villacorta, PhD Jose Aguiar-Moya, PhD Luis Loria-Salazar, PhD August 31 st, 215
Research Philosophy NANO MICRO MACRO FULL SCALE
Phase I Experiment 4 Different pavement structures, 8 sections Compare Asphalt concrete thicknesses Granular vs. cement treated base Evaluate construction practices Painting evaluation under tropical climate
Test Section AC1 AC2 AC3 AC4 Thickness, cm 1 2 3 4 5 CTB GB GB CTB 5 1 15 2 Thickness, in Real pavement 6 7 25
Phase I Experiment Sifón-La Abundancia
Instrumentation Laser profiler Pavement Strain Transducers (PAST) Soil Pressure Transducers (SOPT) Multi-Depth Deflectometer (MDD) Road Surface Deflectometer (RSD) Thermocouples
Gauge Array 3 cm 6 cm 9 cm MDD Thermocouple MDD Section Length = 6. m GB/CTB Subbase Subgrade
Test Settings 2, bi-directional load repetitions per day Carriage speed: 1 km/hr Applied load: 4, 6, 7, 8 kn Test tire: Dual 11R22-5 Wheel wandering: 1 mm Dry condition 23/7
Facility improvements
Material Properties Granular and CTB Property Subgrade Subbase Base Base for CTB CTB Wopt (%) 52.5 8.9 8.6 11.5 11.5 gd max (kg/m 3 ) 156 224 2217 213 213 LL 56 - - 24.8 - PI 16 NP NP 4.4 - CBR, % 6.6 95 95 Pend. 35 kg/cm2 QC Specs NMAS, mm 19 AC, % 4.9 VMA 14.9 Min 14% VFA 72 65-75% Estability, Kg 1482 Min 8 Flow 3 2-35 cm/1 DP 1.4.8-1.3 Sieve Passing, % Specs 25.4 mm 1 1 19.1 mm 99 9-1 12.7 mm 77 7-8 9.5 mm 65 55-65 N 4 41 35-43 N 8 28 22-3 N 16 2 16-22 N 3 14 11-17 N 5 1 7-14 N 2 4.9 2-5.8
FWD. Sensor Location (mm) 2 4 6 8 1 12 14 16 18 2 1. 2. FWD Deflection (mm E -2) 3. 4. 5. 6. 7. 8. AC1 AC2 AC3 AC4 Thickness, cm 1 2 3 4 5 6 7 CTB GB Test Section AC1 AC2 AC3 AC4 GB Layer M (MPa) M (ksi) 38 551 CTB 12 174 Base 17 25 Subbase 14 2 Subgrade 7 1 CTB 5 1 15 2 25 Thickness, in
Laser Profile MDD s
Permanent Deformation-Laser 14. Permanent deformation, mm 12. 1. 8. 6. 4. 2. 12.64 1.16 6.13 AC1 AC4 AC2 AC3 2.57. 5 1 15 2 MESALs Average deformation (entire section) Thickness, cm Test Section AC1 AC2 AC3 AC4 1 2 CTB GB GB CTB 3 4 5 6 7 5 1 15 2 25 Thickness, in
IRI 3. 2.5 2.5 2.46 IRI (m/km) 2. 1.5 1..5. 1.99 AC1 AC4 AC2 AC3 Average of wheelpath 1.17 5 1 15 2 MESALs Thickness, cm Test Section AC1 AC2 AC3 AC4 1 2 CTB GB GB CTB 3 4 5 6 7 5 1 15 2 25 Thickness, in
Stress @ subgrade Pressure, kpa 4 35 3 25 2 15 1 5 AC1 AC2 AC4 2 4 6 8 1 12 14 16 18 2 MESALS AC3 pressure cell did not work Thickness, cm Test Section AC1 AC2 AC3 AC4 1 2 CTB GB GB CTB 3 4 5 6 7 5 1 15 2 25 Thickness, in
MDD s 3 cm 6 cm 9 cm MDD Thermocouple MDD.5 Section Length = 6. m -.5 1 2 3 4 5 6 Deflection, mm -.1 -.15 -.2 -.25 -.3 mdd1- mdd1-18 mdd1-45 mdd1-7 mdd2-6 mdd2-3 mdd2-6 mdd2-9 Distance, m
Max. Deflection @ 4 kn - MDDs MDD Surface Deflection, mm 1.4 1.2 1.8.6.4.2 AC1 AC4 AC2 AC3 5 1 15 2 MESALS Surface MDD Subgrade Deflection, mm.5.4.3.2.1 AC1 AC4 AC2 AC3 5 1 15 2 MESALS Thickness, cm 1 2 3 4 5 Subgrade Test Section AC1 AC2 AC3 AC4 CTB GB GB CTB 5 1 15 2 Thickness, in 6 7 25
AC1 MDD Backcalculaded Layer Moduli Backcalulated Modulus, MPa 1 1 1 1 1 M1 M2 M3 C 25 5 75 1 Repetitions Estimated Deflection, mm-3 7 6 5 4 3 2 1 Deflection Equality y = 1.16x R² =.9962 1 2 3 4 5 6 7 Measured Deflection, mm-3 E SR σ d C MPa =.1 Average n value = -.4 n Deflections @ 4 kn CR-ME
RSD-AC1 Deflections @ 4 kn 3 cm 6 cm 9 cm 1 cm RSD N1 RSD N2 RSD S1 MDD MDD RSD S2 Deflection, mm 1.9.8.7.6.5.4.3.2.1 N1 S1 N2 S2 1 2 3 4 5 6 7 8 9 1 Repetitions Construction variability!!!
RSD-AC4 1 1 Backcalculated Modulus, MPa 1 1 1 CTB G SG 5 1 15 2 MESALs Backcalculated Modulus, MPa 1 1 1 CTB G SG 5 1 15 2 MESALs 2 different locations along the center line
Strain Transducers 5 5 4 3 Longitudinal Transverse 4 3 Longitudinal Transverse Microstrain 2 1 MicroStrain 2 1-1 -1-2 1 2 3 4 5 6 Distance, m -2 1 2 3 4 5 6 Distance, m AC2 @ 2k rep. AC2 @ 1M rep. Strains @ 4 kn
Strain Transducers Microstrain 8 7 6 5 4 3 2 1 Longitudinal Transverse 1 2 3 4 5 6 7 8 9 1 MESALS AC2 Water added to surface Strains @ 4 kn
AC2
Strain Transducers Microstrain 9 8 7 6 5 4 3 2 1 Evidence of fatigue cracking Longitudinal Transverse 2 4 6 8 1 12 14 MESALS AC3 Strains @ 4 kn
Fatigue cracking AC3
Just over 5 Million ESALs Test section Repetitions ESALS 1 AC1 1 1 78 4 2 AC4 1 5 21 55 195 3 AC2 1 9 35 541 4 AC3* 1 24 * 11 66 122* *Until August 215
Deflection Analysis Initial state Sensor Location, mm 5 1 15 2 Surface Modulus, MPa 2 4 6 8 Deflection, mm-3 1 2 3 4 FWD RSD MDD Sensor Location, mm 4 8 12 16 FWD RSD MDD 5 2 Captures non-linear behavior of the lowers layers.
Deflection Analysis Failure State Sensor Location, mm 5 1 15 2 Surface Modulus, MPa 5 1 15 2 25 Deflection, mm-3 2 4 6 8 1 12 FWD RSD MDD Sensor Location, mm 4 8 12 16 FWD RSD MDD 14 2 2.5 3 times higher More intensified non-linear behavior of the lowers layers. Exhibits the presence of the test pit concrete support layer (shallow rigid layer).
Lab. Characterization APA (AASHTO TP 63) HWT (AASHTO T324) FN (AASHTO TP 79-11) Sample Plant Produced Lab Prepared % Air Voids PD, mm % Air Voids PD, mm FN @ 58 C FN @ 52 C FN @ 46 C 7.7 2.751 7.5 3.35 178 418 1523 7.9 2.121 8 8.28 153 37 1493 Sample TSR (AASHTO T283) Mr (AASHTO TP31-96/ASTM 4123) Mr @ 5 C, Mr @ 25 C, Mr @ 4 C, 1 Cicle 3 Cicles 6 Cicles % Air Voids MPa MPa MPa Plant Produced 11 85 77 7.7 17362 573 227 Lab Prepared 96 78 62 7.2 17522 5619 2121 Repetitions 1 1 1 1 1 Plant 3 C Plant 2 C Plant 1 C Lab 3 C Lab 2 C Lab 1 C 4PBB Test (AASHTO T321) 2 4 6 8 1 Strain
Transfer functions Perm. Def. Fatigue Perm. Def. Gran. Base Perm. Def. Subgrade εε pp εε rr = e 1.919 TT 2.961 NN.355 NN ff = e 37.352 (εε) 4.554 ee.94tt εε pp = 1 4,998 NN,69 σσ 1,687 dd σσ,77 3 %ww 1,881 εε pp = 1 32,954 NN,4 σσ 2,41 dd σσ,421 3 %ww 16,983 Lab developed models are being calibrated with HVS results
Linked to software development
FUTURE Climatic Condition Chamber -Infrared + UV: Temperature + aging - Raining system moisture - Water table simulation
Summary Increase in Deflections Increase in vertical stress Increase in horizontal strain Cumulative damage Visible low severity cracks (fatigue) within effective section for AC2, AC3 (granular base). Cracking pattern initiates with transverse cracks @ 3 cm, then @15, finally blocks are formed
Thank You! http://www.lanamme.ucr.ac.cr/pavelab
APT 216 Important dates 1. October 9, 215: Deadline for submission of full paper for peer review 2. January 15, 216: Comments, notification of acceptance/rejection of full paper 3. March 11, 216: Submission of full, revised paper September 19-21, 216: APT 212 Conference