A Study Of The Physical Properties Of High Early Strength Cement

Author : Kenneth L. Saucier
Publisher :
ISBN 13 :
Total Pages : 39 pages
Book Rating : 4.:/5 (227 download)

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Download or read book Determination of Practical Ultimate Strength of Concrete written by Kenneth L. Saucier and published by . This book was released on 1972 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.