01620226

Component

https://doi.org/10.3141/2655-04

Unbound aggregate base and subbase layers are the main load-bearing layers in a pavement structure. Size and shape properties of these aggregate materials should be controlled to ensure proper workability during construction and improved performance for pavement longevity. The effects of gradation, maximum particle size, fines content (percentage passing the No. 200 sieve), and dust ratio on the quality of aggregates were investigated by performing many soaked California bearing ratio tests on a crushed limestone material. The dust ratio represents the amount of fines content divided by the amount of minus No. 40 sieve material. The dust ratios studied were 0.4, 0.6, and 1.0. Two gradations commonly used in Illinois, with maximum particle sizes of 1 in. and 2 in., were studied to analyze the effect of fines content with respect to maximum particle size in the gradation. A typical range of fines contents (i.e., 5%, 8%, and 12%) was also considered. The results show that the gradation, dust ratio, and fines content should be taken into account in the selection of aggregate properties for stability requirements. Aggregates with larger maximum size particles provide high strength, and they are not affected as much as aggregates with smaller maximum size particles by an increase in fines content. The aggregates with smaller maximum size particles provide lower strength. It was also concluded that samples with a dust ratio of 1.0 do not necessarily result in an aggregate material with low strength.

01629558

17-03384

English

pp 20–26

2017

Transportation Research Record: Journal of the Transportation Research Board

9780309441568

Digital/other

Figures (7) ; References (18) ; Tables (1)

Aggregates; Base course (Pavements); Fines (Materials); Grain size (Geology); Subbase (Pavements)

Geotechnology; Highways; Materials; Pavements

PRP, TRIS, TRB, ATRI

Dec 19 2016 1:11PM

• Case Study on the Use of Mobile Lidar to Produce a Preliminary Drainage Design
• Ethylene Glycol Accelerated Weathering Test: An Improved, Objective Aggregate Durability Test Method
• Evaluating Constructed Aggregate Layers of Working Platforms and Flexible Pavements: Adequacy of In-Place Quality Control and Quality Assurance Techniques
• 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