Construction and Performance Evaluation of Roller Compacted Concrete under Accelerated Pavement Testing TRB Paper No: 15-1944 Moinul Mahdi Zhong Wu, PhD., P.E. Tyson Rupnow, PhD., P.E. Jan 14, 2015 TRB Annual Meeting

Outline Background Objectives Construction and Instrumentation Accelerated Loading on RCC Pavement Sections Summary and Conclusion 2

Project Details Six full-scale, RCC-surfaced pavement test sections were constructed at the PRF of LTRC Each section: 71.7-ft long and 13-ft wide Sections 1-3: Design alternative for those low-volume roads having significantly heavy truck traffic Sections 4-6: Design alternative for high-volume roads using a treated subgrade layer 3

Project Details [cont.] The final design gradation and corresponding RCC mix quantities used in this study were designed at the LTRC’s concrete research lab. Mix Quantities Max Dry Density (pcf) 146.0 Max Wet Density (pcf) 155.5 Optimum % Moisture 6.5 Coarse Aggregate Absorption % 0.2 Fine Aggregate Absorption % 2.1 % Cemetitious 11.4 % Cement %Fly Ash 0.0 Target Coarse Aggregate % 45.0 Target Fine Aggregate % 55.0 You can get more details about the mix design in the paper. We use a ….. For cement application Cement contents for base layer were determined by DOTD TR 432 to achieve 7-day UCS of 150 or 300 psi. 6% cement by volume was used for sections 1-3 (cement treated base) 8% cement by volume was used for sections 4-6 (soil cement) 4% cement by volume was used for treated subgrade 4

In Situ Testing Results during the Construction of RCC Sections

In Situ Testing during the Construction Field Testing Methods FWD/LFWD Surface roughness/walking profiler RCC Surface Texture & Friction Sand patch and dynamic friction tester Proval was used to convert the walking profiler to IRI 6

FWD Backcalculated Layer Moduli 8”RCC+12CT 6”RCC+12CT 4”RCC+12CT Section 1 Section 2 Section 3 8”RCC+8.5SC 6”RCC+8.5SC 4”RCC+8.5SC The RCC modulus of sec 4-6 is higher than sec 1-3 and comply with the field core laboratory results The base modulus of soil cement was also high The subgrade modulus was high due to 10in. Treated subgrade Section 4 Section 5 Section 6

Surface Roughness, Friction & Texture Section IRI (in/mile) Section 1 359.5 Section 2 469.7 Section 3 622.7 Section 4 190.1 Section 5 122.2 Section 6 167.5 Average 322 Rougher surface due to paving speed and coarser gradation High Surface Roughness due to Paving Speed, Paver type, Manufactured sand and Coarser Aggregate Gradation Similar to Superpave mixes on surface friction and macrotexture

Accelerated Pavement Testing - ATLaS30 Dual-tire load, 130 psi Bi-directional loading Load: up to 30 kips Effective length: 42-ft Speed: 3~6 mph About 10,000 passes/day 9

Cracking and Pumping (8 in. RCC) After 53,000 repetitions of 25-kip load, Section 4 developed both transverse and longitudinal cracking; Joint pumping also observed under heavily raining weather, > 3 in. rainfall overnight

Results and Discussion (8 in. RCC) The estimated ESALs based on AASHTO method ≈ 10.9 million Based on Miner’s Cumulative fatigue damage law: -the total damage > 100% when MR=600 psi -the total damage ≈ 41% when MR=800 psi Whether or not this should be considered as the test section failure is under further investigation   Our field MR was 667 psi Currently observing the Crack Propagation, Joint Faulting, IRI and any major visual distress to identify failure.

The Current Conditions of RCC Sections Section 5 (6 in. RCC) No distress was observed Approximately 12.1 million ESALs Further testing will be performed till failure. Section 6 (4 in. RCC) Several cracks, pumping and spalling was observed Approximately 19.0 million ESALs IRI values went up to 268.8 in/mile from 167.5 in/mile

The Current Conditions of RCC Sections CL 20’ 20’ Longitudinal Crack Length: 2’- 5” Transverse Crack Length: 2’ - 8” 8”RCC 15’ CL 15’ 15’ 15’ 6”RCC No Cracks 10’ 10’ 10’ CL 10’ 10’ 10’ 4”RCC Several Cracks are Observed

Summary and Conclusion The failure criteria of RCC pavements under APT loading need further investigation; As of now the tested RCC sections had performed better than expected; Both RCC-Pave and PCC fatigue models did not seem to fit for the prediction of fatigue damage of this sections; A new fatigue damage model is expected to be developed in this study for thin RCC-surfaced pavement.

Thank you! Moinul Mahdi mmahdi2@lsu.edu 225-614-8874 16