874 resultados para plastic mulch
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Includes index.
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"May 1970."
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"August 1962."
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Includes index.
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"May 1970."
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"5 May 1982."
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Includes bibliographical references (p. 29-31).
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Selected references: p. 27-28.
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"Issued June 1949."
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Thesis (Ph.D.)--University of Washington, 2016-06
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The ACI recommendations for the prevention of cracking of plastic concrete attempt to eliminate such cracking by ensuring that the rate of evaporation from unprotected concrete surfaces does not exceed the estimated rate of bleed water production. The current recommendations, however do not account for the large scatter of the underlying experimental evaporation data nor the effect of altitude on evaporation rate. Ignoring the scatter of the evaporation data frequently leads to an unacceptably high probability that the evaporation rate will exceed the bleed rate. Ignoring the effect of altitude leads to similar high probabilities, but in only a comparatively small number of cases. Simple modifications of the ACI recommendations are suggested that can account for both effects. However; insufficient data on the variability of bleed rates are currently available to allow the scatter of the evaporation data to be accounted for completely.