Process for placing cement composition having high strength
AssigneeHazama-Gumi, Ltd.
InventorsKeiichi Fujita, Hiroshi Nakauchi, Tatsuo Kita, Yoshiki Nakagawa, Terunobu Maeda
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Abstract
A process for placing a cement composition having high strength is provided. The process comprises the steps of adding a viscosity increasing agent, vacuum de-bubbling under reduced pressure and allowing the de-bubbled cement composition to be hardened. At the vacuum de-bubbling step, relatively large foams present in the cement composition are removed and only fine bubbles are left in the composition. The strength of the cement composition is remarkably improved by the removal of large bubbles.
Claims17
A process for placing a cement composition having high strength comprising the steps of:
- adding a viscosity increasing agent to a cement to prepare a cement composition containing said viscosity increasing agent;
- vacuum de-bubbling said cement composition containing said viscosity increasing agent under a reduced pressure to remove relatively large bubbles present in said cement composition and to leave therein only fine bubbles so that 98 vol% or more of the total sum volume of all of the bubbles left after the vaccum de-bubbling are composed of the sum volume of the bubbles each having foam size of not more than 120 microns;
- and then allowing the defoamed cement composition to be hardened.
Dependencies are inferred from the claim text.