| 摘要 |
PROBLEM TO BE SOLVED: To use unwashed sand and gravel by mixing unwashed gathered sand and gravel and a vibrating fluidizer under the conditions of a cement quantity equal to that of an ordinary dam concrete and a water cement ratio, and placing the mixture in a construction side and performing vibrating compaction for the mixture. SOLUTION: Concrete is prepared under the conditions of a cement quantity equal to that of an ordinary dam concrete and a water cement ratio. Gravels 80 mm or more, which are unwashed sand and gravel are mixed as aggregate with the concrete, an agent which is mainly composed of water soluble vinyl copolymer formed of carboxyl group contained polyether is mixed as a vibrating fluidizer, and they are mixed to prepare a dam concrete. The dam concrete is placed in a construction site, and then subjected to vibrating compaction. Thus, in the construction of the concrete dam, unwashed sand and gravel at the river bed can be used as aggregate whether it is internal concrete or external concrete. |
