|
|
|
Title: SULFUR-MODIFIED BOTTOM ASH AS AGGREGATE IN HOT-MIX ASPHALT CONCRETE: FIELD DEMONSTRATION PROJECT
Accession Number: 00803765
Record Type: Component
Record URL: Availability: Transportation Research Board Business Office 500 Fifth Street, NW Find a library where document is available Abstract: The use of bottom ash in road construction as an aggregate for both roadway surfaces and base courses has been limited because of its absorbency and friability. The former tends to increase asphalt binder demand, and the latter adversely affects its ability to withstand the crushing effects of traffic loads. Nevertheless, bottom ash is lighter in weight and generally much cheaper than conventional quality aggregates such as crushed limestone, sand, and gravel. Research was undertaken to upgrade the load-bearing characteristics of bottom ash and maximize its use in asphaltic concrete mixtures through sulfur modification. The process essentially coats the ash with liquid sulfur, which, upon cooling, fills the voids on the surface of the particles while increasing their crushing resistance. The results of laboratory investigations indicate that asphaltic concrete mixture designs in which bottom ash represents 50 to 100% of the aggregate fraction can be achieved. Sulfur-modified bottom ash (SMBA) mixtures compare favorably with typical Texas Department of Transportation surface course mixtures in terms of strength, durability, and asphalt demand. Results of a field demonstration project in which SMBA was incorporated into hot-mix asphalt concrete are presented. An asphalt batch plant was successfully used to incorporate the sulfur into the bottom ash and produce the hot-mix asphalt concrete. The mixture was successfully placed as a 50-mm (2-in.) overlay on an existing asphalt surface at the entry to the asphalt plant facility, and adequate density was achieved with standard compaction equipment. The SMBA hot-mix overlay is currently under traffic by heavy haul trucks entering the plant facility, and early indications of performance are good.
Supplemental Notes: This paper appears in Transportation Research Record No. 1723, Part 2: Asphalt Mixtures 2000.
Language: English
Corporate Authors: Transportation Research Board 500 Fifth Street, NW Authors: Estakhri, C KSaylak, DPagination: p. 57-65
Publication Date: 2000
Serial: ISBN: 0309067251
Features: Figures
(7)
; Photos
(5)
; References
(8)
; Tables
(2)
TRT Terms: Subject Areas: Construction; Design; Freight Transportation; Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways; I23: Properties of Road Surfaces; I31: Bituminous Binders and Materials; I52: Construction of Pavements and Surfacings
Files: TRIS, TRB, ATRI
Created Date: Nov 30 2001 12:00AM
More Articles from this Serial Issue:
|
