ACCELERATED PAVEMENT TESTING FIRST RESULTS AT THE LANAMMEUCR APT FACILITY

Phase I Experiment 4 Different pavement structures, 8 sections Compare Asphalt concrete thicknesses Granular vs. cement treated base Evaluate construction practices

Phase I Experiment AC1 AC2 AC4 AC3

Phase I Experiment AC1 AC2 AC4 Completed

Phase I Experiment AC1 Results for this Test Section

Instrumentation Laser profiler Soil Pressure Transducers Multi-Depth Deflectometer (MDD) Road Surface Deflectometer (RSD) Thermocouples Asphalt strain gauges Moisture sensors AC1

Subgrade SOPT

Layer deflections MDD

Gauge Array AC1 HMA CTB Subbase Subgrade Section Length = 6.0 m 30 cm MDD MDD Thermocouple Section Length = 6.0 m AC1 HMA CTB Subbase Subgrade

Test Settings 15,000 – 20,000 bi-directional load repetitions per day Carriage speed: 10 km/h Applied load: 40, 60, 70, 80 kN Test tire: Dual 11R22-5 Wheel wandering: 100 mm Dry condition AC1

Material Properties AC1 Granular and CTB HMA Property Subgrade Subbase Wopt (%) 52.5 8.9 11.5 gd max (kg/m3) 1056 2204 2013 LL 56 - -  PI 16 NP CBR, % 6.6 95 35 kg/cm2 AC1 HMA QC Specs NMAS, mm 19   AC, % 4.9 VMA 14.9 Min 14% VFA 72 65-75% Estability, Kg 1482 Min 800 Flow 30 20-35 cm/100 DP 1.04 0.8-1.3 Sieve Passing, % Specs 25.4 mm 100 19.1 mm 99 90-100 12.7 mm 77 70-80 9.5 mm 65 55-65 N 4 41 35-43 N 8 28 22-30 N 16 20 16-22 N 30 14 11-17  N 50 10  7-14 N 200 4.9  2-5.8

GPR AC1 Copper Plates Layer Thickness AC1 + AC2

FWD AC1 Layer Modulus (Mpa) Modulus (ksi) HMA 3800 551 CTB 1200 174 Subbase 140 20 Subgrade 70 10 AC1

Results AC1 AC1 AC4 AC3 AC1 AC2

Laser Profile MDD´s

Permanent Deformation 3D profile @ 1 million repetitions AC1

Permanent Deformation Target Rut Depth 12.5 mm

Roughness IRI AC1

Stress @ subgrade

Stress @ subgrade AC1

MDD´s 30 cm 60 cm 90 cm MDD MDD Thermocouple Section Length = 6.0 m

MDD Deflection @ 40 kN & Perm. Def. AC1

MDD Backcalculaded Layer Moduli MET Average “n” value = -0.4

RSD 60 cm MDD 30 cm 90 cm RSD – N1 RSD – N2 RSD – S2 RSD – S1 100 cm

Deflection Analysis Initial state Captures non-linear behavior of the lowers layers.

Deflection Analysis Failure State More intensified non-linear behavior of the lowers layers. Exhibits the presence of the test pit concrete support layer (shallow rigid layer). 2.5 – 3 times higher

Backcalculated Moduli Initial state, Modulus in MPa LAYER FWD MDD LAB HMA (@25 °C) 3800 3000 6550 (10 Hz) BASE 1200 2545 SUBBASE 140 480 SUBGRADE 70 90

Modeling – 3D Move 3D Move Pavement Analysis software uses a continuum-based finite-layer approach. NCHRP 1-37A performance prediction models (U.S. nationally calibrated):   AC Top Down Cracking; 2. AC Bottom Up Cracking; 3. AC Rutting; 4. Base Rutting; 5. Subbase Rutting; 6. Subgrade Rutting.

Modeling – 3D Move Layer Distress Type Distress Target Distress Predicted Actual Result Asphalt (1) AC Top Down Cracking (m/km) 190 0.47 Non visible AC Bottom UP Cracking (%) 25 4.81 AC Rutting (mm) 6.4 7.4 7.2 CTB (2) Base Rutting (mm) 7.6 0.8 1.9 Subbase (3) Subbase Rutting (mm) 1.3 1.8 Subgrade (4) Subgrade Rutting (mm) 5.1 1.6

Summary AC1 Performance variability = f(Construction variability) Increase in Deflections Increase in vertical stress MDD & RSD sensors confirmed expected trends (failure) Results can be use to calibrate and / or validate pavement design methodologies. Cumulative damage

Phase I Experiment Currently developing performance models: AC Rutting AC Fatigue

Thank You! http://www.lanamme.ucr.ac.cr/pavelab

APT 2016 Important dates February 27, 2015: Call for papers June 5, 2015: Deadline - submission of abstract July 10, 2015: Notification of acceptance of abstracts/posters October 9, 2015: Deadline for submission of full paper for peer review January 15, 2016: Comments, notification of acceptance/rejection of full paper March 11, 2016: Submission of full, revised paper (poster) September 19-21, 2016: APT 2012 Conference