RECYCLING ASPHALT PAVEMENTS & ROADBEDS
Faced with the problems of pavement deterioration, pavement designs which were no longer adequate to meet current needs and standards, and the rising costs of both asphalt cement and portland cement, Kossuth County embarked on a project which involved recycling existing asphalt pavements and their gravel-clay subbases. Construction operations consisted of salvaging recyclable material and gravel-clay subbase, widening of the roadbed, construction of the subbase, crushing and processing of the recyclable material, and placing a surface course over the recycled base. Specifications required that the salvaged material be crushed to a maximum size of 2 in. (5.08 cm). Either recyclable asphalt aggregates only or recyclable asphalt material with the addition of new aggregates (30%) were used. A variable percentage of virgin asphalt (2.5-4.5%) was added. A major problem encountered was smoke emission during mixing. This was controlled when 3% moisture was added, production was maintained at 275-300 tons per hr (249,460-272,160 kg per hr), mix temperature was kept at 225 deg F (107 deg C), and 30% limestone was added to the mix. The project was economically beneficial to Kossuth County since the County had no locally available aggregate source and haul distances from an outside source were relatively long. Cost savings were also realized through use of the recycled materials.
Kossuth County, IowaAalgonna, IA USA
- Henely, R P
- Publication Date: 1975-11
- Features: Tables;
- Pagination: 29 p.
- TRT Terms: Aggregate gradation; Air quality management; Asphalt pavements; Construction management; Costs; Crushing; Economics; Limestone aggregates; Mixing; Smoke; Specifications; Subgrade (Pavements); Temperature
- Old TRIS Terms: Construction operations
- Subject Areas: Construction; Economics; Finance; Highways; Materials;
- Accession Number: 00128481
- Record Type: Publication
- Files: TRIS
- Created Date: May 14 1976 12:00AM