1. ERDC Knowledge Core
2. Pre - Engineer Research and Development Center (ERDC)
3. Concrete Laboratory - (8/1/1972 - 4/16/1978)
4. Publication
5. Miscellaneous Paper

Title:	Determination of practical ultimate strength of concrete
Authors:	United States. Assistant Secretary of the Army (R & D). Saucier, K. L.
Keywords:	Compressive strength Concrete strength Concrete tests
Publisher:	Concrete Laboratory (U.S.) Engineer Research and Development Center (U.S.)
Series/Report no.:	Miscellaneous paper (U.S. Army Engineer Waterways Experiment Station) ; C-72-16.
Description:	Miscellaneous paper Abstract: 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 (s 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. The addition of wire fibers yields higher early strength; however, the cost of the fibers negates the slight strength advantage. Polypropylene fibers, or flakes, as used in this study actually reduced strength; (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. Density, Young's modulus, and creep are likely to be slightly higher, depending on the aggregates used, The ratios of flexural, tensile, and bond strengths to compressive strength are likely to be lower for ultrahigh-strength concrete compared to normal concrete. The maximum practical ultimate strength of portland-cement concrete attainable with present-day technology and without use of exotic materials or specialized procedures is approximately 15,000 psi.
Rights:	Approved for public release; distribution is unlimited.
URI:	http://hdl.handle.net/11681/11490
Appears in Collections:	Miscellaneous Paper