THIN CONCRETE OVERLAY FOR RESIDENTIAL STREETS
HAD A SIX-INCH REINFORCED CONCRETE SLAB WITH INTEGRAL THE STREET WHICH WAS ADJACENT TO AN ASPHALT OVERLAY THAT COULD SERVE AS A CONTROL SECTION FOR EVALUATION, HAD A SIX-INCH REINFORCED CONCRETE SLAB WITH INTEGRAL CURB AND GUTTER OVER A POOR, COMPACTED SOIL BALL, AND WAS CRACKED IN MANY LOCATIONS WITH BREAKS OF TWO-AND- ONE-HALF TO THREE IN. IN DEPTH. CONSTITUENTS OF THE FIBROUS CONCRETE MIX WHICH WAS USED TO OVERLAY THE STREET ARE DETAILED. BRASS COATED AND PLAIN STEEL FIBERS WERE HAND SORTED, RAKED OUT AND PUSHED THROUGH A HOPPER WITH A GRATE NEAR THE BOTTOM TO PREVENT PRE- BALLING. THE BRASS COATED FIBERS CAUSED THE PROBLEM WITH BALLING UP AND A SHUTE CONVEYED THE FIBERS DIRECTLY FROM THE HOPPER TO THE CONCRETE TRUCK. THE FIBERS FOLLOWED BY ALL OF THE CEMENT AND FINAL 30 PERCENT OF THE WATER WAS ADDED TO THE TRANSIT MIX TRUCK PRECHANGED WITH ALL OF THE AGGREGATE AND 70 PERCENT OF THE WATER. THE TRUCKS DUMPED THE WET CONCRETE ON THE PREVIOUSLY WET DOWN PAVEMENT AHEAD OF THE FINISHER. THE MIX WAS SPREAD BY HAND RAKERS, FINISHED BY AUGER-ROLLER ON THE FINISHING MACHINE, HAND FINISHED WITH MAGNEWSIUM LUTES, AND FINALLY BROOM- FINISHED. THE ROAD WAS OPEN TO TRAFFIC IN TWO DAYS. THE FIBERS ALTHOUGH VISIBLE ARE FIRMLY IMBEDDED AND POLISHED AND NO RUSTING IS APPARENT. TEST CYLINDERS FROM A NINE SACK MIX WITH 6.7 PERCENT AIR ENTRAINMENT SHOWED A SEVEN-DAY COMPRESSIVE STRENGTH OF 5,700 PSI AND A 28-DAY GAIN TO 7,550 PSI. FLEXURAL STRENGTHS FOR THESE CYLINDERS RAN 860 PSI AT SEVEN DAYS AND 900 PSI AT 14 DAYS. PERFORMANCE TO DATE OF THE FIBROUS CONCRETE OVERLAY IS SATISFACTORY.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/oclc/1519687
- Publication Date: 1973-4
Media Info
- Features: Photos;
- Pagination: p. 24-6
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Serial:
- Better Roads
- Volume: 43
- Issue Number: 4
- Publisher: James Informational Media, Incorporated
- ISSN: 0006-0208
- Serial URL: http://www.betterroads.com
Subject/Index Terms
- TRT Terms: Admixtures; Brass; Concrete finishing; Fibers; Fracture mechanics; Material reinforcement; Overlays (Pavements); Reinforced concrete; Repairing; Residential areas
- Old TRIS Terms: Brasses
- Subject Areas: Highways; Materials;
Filing Info
- Accession Number: 00214241
- Record Type: Publication
- Files: TRIS
- Created Date: Oct 24 1973 12:00AM