DETERMINATION OF PRACTICAL ULTIMATE STRENGTH OF CONCRETE
The purpose of this study was to investigate the circumstances surrounding the production of structural grade concrete of maximum compressive strength which could be utilized in actual field construction. Five methods were investigated with the following results: a. Depending on the degree of harshness which can be tolerated, mixtures with low water-cement ratios (+ or - 0.26) can be proportioned to yield strengths of 15,000 psi by careful control of materials, mixing, consolidation, and curing, b. Compaction by application of 100-psi pressure applied overnight to plastic concrete can be expected to yield a strength increase of 10 percent on relatively dry (W/C = 0.30) mixtures, but no increase in very dry (W/C = 0.26) mixtures, c. The addition of fibers shows little promise of increasing the compressive strength of high-strength concrete sufficiently to warrant their use. d. The use of a high-frequency vibrator (18,000 cps) on relatively stiff concrete (0-in. slump) did not increase the compressive strength when compared to normal frequency vibrators; (7000-10,000 cps). e. Vibroactivation, or vibration during mixing, results in higher early strength of high-strength concrete, but appears to be of no benefit between 28 to 90 days age. Concrete specimens revibrated after 2 hours delay yielded an additional 8 percent strength compared to nonrevibrated specimens for the one mixture tested. Other physical properties of ultrahigh-strength concrete are likely to be only slightly different from normal high-strength concrete.
U.S. Army Waterways Experiment Station3909 Halls Ferry Road
Vicksburg, MS United States 39180-6199
- Saucier, K L
- Publication Date: 1972-6
- Pagination: 39 p.
- TRT Terms: Building materials; Compaction; Compressive strength; Concrete; Density; Fibers; High frequency; Mechanical properties; Mixing; Modulus of elasticity; Physical properties; Polymer concrete; Production; Reinforced concrete; Strength of materials; Ultimate strength; Vibration; Water cement ratio; Wire
- Uncontrolled Terms: Compressive properties
- Subject Areas: Highways; Materials;
- Accession Number: 00146258
- Record Type: Publication
- Source Agency: National Technical Information Service
- Report/Paper Numbers: WES-MP-C-72-16 Final Rpt.
- Files: TRIS
- Created Date: Jan 16 1977 12:00AM