01620101

Component

https://doi.org/10.3141/2655-05

Ethylene glycol has been used extensively by the concrete and road construction industries to identify rock durability issues associated with smectite clay minerals. The presence of these clay minerals is synonymous with rock degradation under normal environmental wetting and drying cycles. However, such historical test methods are predominately based on a subjective visual interpretation, describing the observed degradation of individual rock pieces at fixed time intervals during the soaking process. In addition, some test methods include complex equations with multiple weighting factors applied to nominated degradation descriptors (e.g., spalling, fracture, and disintegration) used to calculate a single durability indicator. This paper describes the development and implementation of an alternative, nonsubjective accelerated weathering test that also uses ethylene glycol. The research included metamorphic and volcanic rock types used extensively in New Zealand for road construction. The greatest benefit of the proposed new test method is the ability to eliminate the subjective visual assessment described in historical test methods and adequately quantify results to specify contractual acceptance and rejection criteria. The test method also shows that good repeatability is possible from duplicate test samples. However, rock quality and quarry production consistency will influence the ability of the test method to report the same "percentage change in fines" over a prolonged test period. This phenomenon was particularly evident with problematic and lower quality rock. The test findings are well supported by observed field performance, thus giving confidence in the new method’s usefulness.

01629558

17-01772

English

pp 27–35

2017

Transportation Research Record: Journal of the Transportation Research Board

9780309441568

Digital/other

Figures (1) ; References (12) ; Tables (4)

Accelerated weathering; Durability tests; Ethylene glycol; Metamorphic rocks; Mineral aggregates; Test procedures; Volcanic aggregates

New Zealand

Geotechnology; Highways; Materials; Pavements

PRP, TRIS, TRB, ATRI

Dec 8 2016 10:37AM

• Case Study on the Use of Mobile Lidar to Produce a Preliminary Drainage Design
• Evaluating Constructed Aggregate Layers of Working Platforms and Flexible Pavements: Adequacy of In-Place Quality Control and Quality Assurance Techniques
• Influence of Maximum Particle Size, Fines Content, and Dust Ratio on the Behavior of Base and Subbase Coarse Aggregates
• Permanent Strain Behavior of Marginal Granular Material
• Results of Soaked and Unsoaked California Bearing Rate Tests on Unbound Aggregates with Varying Amounts of Fines and Dust Ratios
• Shear Wave Velocity Profiles of Roadway Substructures from Multichannel Analysis of Surface Waves and Waveform Tomography
• Strain Rate Effect on Shear Behavior of Open-Graded Aggregates
• Use of Time Domain Reflectometry to Estimate Moisture and Density of Unbound Road Materials: Laboratory Calibration and Field Investigation
• Vibratory Compaction of Base Course Aggregates