MIXING PERFORMANCE OF LARGE CENTRAL PLANT CONCRETE MIXERS
TESTS WERE CONDUCTED TO IDENTIFY AND EVALUATE OPERATING PLANT VARIABLES WHICH AFFECT THE MIXING TIME REQUIRED TO PRODUCE SATISFACTORY QUALITY CONCRETE. THE STUDY EFFORT EMBRACED MULTIPLE SAMPLING AT PLANT AND ROADWAY OF NEARLY 400 TEST BATCHES, NEARLY 2000 TESTS EACH FOR SLUMP, AIR, UNIT WEIGHT AND WASHOUT, PLUS NEARLY 4000 COMPRESSIVE STRENGTH TESTS. EACH SAMPLE WAS TESTED FOR SLUMP, AIR CONTENT, UNIT WEIGHT OF FRESH CONCRETE, COARSE AGGREGATE RETAINED ON THE NO. 4 SIEVE AFTER WASHOUT, AND 28-DAY COMPRESSIVE STRENGTH OF MOLDED 6- BY 12- IN. CONCRETE CYLINDERS. GOOD BLENDING OF AGGREGATE ON THE BELT DURING CHARGING OF THE MIXER, AND GOOD PARALLEL TIMING AND UNIFORMITY IN CHARGING OF CEMENT AND WATER ARE ESSENTIAL TO PRODUCTION OF GOOD QUALITY CONCRETE WITH MINIMUM MIXING TIME . IT IS RECOMMENDED THAT MIXING TIME BE DETERMINED BY MIXER PERFORMANCE TESTS WHERE REASONABLY POSSIBLE AND IN ALL CASES INVOLVING 20,000 CU YD OR MORE OF CONCRETE. TEST RESULTS ALSO INDICATE THAT A SPECIFIED MAXIMUM MIXING TIME MAY BE DESIRABLE.
- Record URL:
-
Supplemental Notes:
- Paper sponsored by Special Committee on Highway Equipment and presented at the 45th Annual Meeting. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
-
Authors:
- Bozarth, F M
- Grieb, W E
- Publication Date: 1967
Media Info
- Media Type: Digital/other
- Features: Figures; Tables;
- Pagination: pp 24-31
- Monograph Title: Concrete construction
-
Serial:
- Highway Research Record
- Issue Number: 160
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Air content; Compressive strength; Concrete; Consistency; Mixing; Samples; Time; Weight
- Uncontrolled Terms: Washout
- Old TRIS Terms: Concrete consistency; Mixing efficiency; Mixing time; Unit weight
- Subject Areas: Construction; Highways; Materials; Vehicles and Equipment;
Filing Info
- Accession Number: 00212390
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Jun 15 1994 12:00AM