| 摘要 |
PURPOSE: To assure sufficient strength and workability even if a unit cement quantity relating to a temp. stress is decreased by decreasing the unit cement quantity and compounding a high-performance water-reducing agent or the high-performance water-reducing agent and welan gum. CONSTITUTION: The unit cement quantity is made smaller by >=10kg/m<3> than the design compounding and the high-performance water-reducing agent, such asβ-naphthalene sulfonnate, etc., is compounded at 0.01 to 0.1wt.% and the welan gum at 0 to 0.1wt.% of the unit water volume, by which the unit cement quantity is decreased to <=210kg/cm<3> and the unit water volume for obtaining prescribed slump is decreased by 5 to 10kg/m<3> at the time of producing dam concrete by mixing the necessary unit cement quantity under compounding design of the slump value of 0 to 6cm to obtain the dam concrete having the target strength. As a result, the water cement ratio does not increase and the compressive strength does not degrade even if the unit cement quantity is decreased by about 10 to 20kg/m<3> . The degradation in viscosity is suppressed and the cost reduction is attained by addition of an admixture (high-performance water-reducing agent + welan gum).
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