A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Underwater Concreting
Most underwater concrete is mixed on the surface in the conventional manner and then placed by one of a variety of methods; occasionally the special process of grouted aggregate is used. In many respects the rules and recommendations for underwater concrete are the same as those for conventional concrete placed in the dry. Properly mixed concrete is a stable material with a density more than twice that of water. Once in position it will remain unaffected by the water in which it is immersed unless it is subjected to agitation or other movement while it is setting. Cement sets as a result of a chemical reaction - not by drying out - so concrete hardens as quickly underwater as in the dry and it generally behaves in a normal manner once it has been successfully placed. However, conventional concrete can be disrupted by the movement of either concrete through the water or water against the concrete causing washout of cementitious materials and fine aggregate at the concrete/water interface. Layers of uncemented aggregate and of soft laitance may be left on the surface or become trapped within the concrete. Vibration, levelling and screeding of concrete underwater can be difficult or impractical because of the danger of mixing water into the concrete. Techniques for forming underwater concrete structures and their possible applications are summarized in the report. (Copyright (c) The Concrete Society 1990.)
Underwater Concreting
Most underwater concrete is mixed on the surface in the conventional manner and then placed by one of a variety of methods; occasionally the special process of grouted aggregate is used. In many respects the rules and recommendations for underwater concrete are the same as those for conventional concrete placed in the dry. Properly mixed concrete is a stable material with a density more than twice that of water. Once in position it will remain unaffected by the water in which it is immersed unless it is subjected to agitation or other movement while it is setting. Cement sets as a result of a chemical reaction - not by drying out - so concrete hardens as quickly underwater as in the dry and it generally behaves in a normal manner once it has been successfully placed. However, conventional concrete can be disrupted by the movement of either concrete through the water or water against the concrete causing washout of cementitious materials and fine aggregate at the concrete/water interface. Layers of uncemented aggregate and of soft laitance may be left on the surface or become trapped within the concrete. Vibration, levelling and screeding of concrete underwater can be difficult or impractical because of the danger of mixing water into the concrete. Techniques for forming underwater concrete structures and their possible applications are summarized in the report. (Copyright (c) The Concrete Society 1990.)
Underwater Concreting
1990
44 pages
Report
No indication
English
Underwater Construction & Habitats , Civil Engineering , Construction Equipment, Materials, & Supplies , Underwater construction , Concrete construction , Tremie concrete , Concrete structures , Concretes , Underwater foundations , Construction materials , Grouting , Placing , Binders , Aggregates , Foreign technology
TIBKAT | 1996
Underwater Concreting (Reannouncement)
NTIS | 1990
Underwater concreting and repair
| TIBKAT | 1994
A review of underwater concreting
| British Library Conference Proceedings | 1986
Polymer Mortars for Underwater Concreting
| British Library Conference Proceedings | 1992