Sandoz Gmbh

Other

Odd M Tjugum

Salvatore Valenti

Josef F Drs

Tom Arild Melbye

Olav G Tjugum

A process for modifying the slump of a concrete or mortar by the addition at different times of a water-soluble poly(alkylene oxide) and a .beta.-naphthalene sulphonate-formaldehyde condensate, a plasticizer or superplasticizer which is selected from lignosulphonates, melamine sulphonate formaldehyde condensates, carboxylates and selected styrene-maleic anhydride copolymers. The poly(alkylene oxide) is preferably partially replaced by a (hydroxy)alkyl cellulose. The process is advantageously used in shotcreting.

Workable cementitious compositions

The present invention relates to a process of casting of repairing concrete under water whereby the concrete (mortar) to be cast to a minimum extent contacts water and leaching of the binding agent is prevented. The purpose of the process according to the invention is achieved such that a 'plug' of liquid organic material based on a reactive or non-reactive synthetic resin or other organic carrier having a suitable viscosity, good cohesion and poor water solubility and with a specific gravity higher than water, but less than cement-based concrete, is introduced into the bottom of a tight formwork to contact a support cement-based concrete having a good flowability is then introduced below the surface level of the plug, the introduction initially being effected in the very plug. The use of a 'plug' of such type, which in contact with the concrete (mortar) to be cast and the support constitutes a phase of its own and for which the affinity can be adjusted according to the actual case, affords the possibility that the adherence to the support of the concrete to be cast can even be increased to an extent that portions of the plug which will cling to the support, preferably in connection with curing of the plug material, in a specific embodiment of the process according to the present invention will act as an effective adhesive.

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Dal, Norway

Odd M Tjugum