RU2164867C1 - Method for winter concreting - "dry hot thermos" - Google Patents

Abstract

FIELD: arrangement of monolithic extended concrete and reinforced-concrete constructions in winter conditions. SUBSTANCE: method consists in placing of a layer of hot expanded clay aggregate at a temperature of 200 to 300 C in an installed warmth-kept formwork directly on a frozen base, it is distributed and packed in the formwork. Then, after the hot expanded clay aggregated gets cooled down to a temperature below 100 C, it is injected by cement-sand mortar. After that a temporary warmth-keeping of the concreted construction is accomplished. EFFECT: prevented power expenditures due to reuse of the heat of the cooling down expanded clay aggregate, solved ecological problem of salvaging of heat of the cooling down expanded clay aggregate. 3 dwg

Description

 The invention relates to the field of device monolithic long concrete and reinforced concrete structures in winter conditions, including the underlying layer of high-speed railways made of monolithic concrete. This method combines the winter concreting method using the heat of hot expanded clay and separate concreting technology.

 Known methods of winter concreting of extended structures (see. "Technology of building processes": Textbook for universities on special. "Industrial and civilian construction"; edited by NN Danilov, OM Terentyev - M. : Higher school, 1997. - 464 p., - pp. 215-236), consisting in the use of the initial heat content of the concrete mixture and exothermic heat dissipation of cement, with the introduction of additional heat in various ways when concreting structures, with a decrease in the eutectic point of mixing water for due to the introduction of antifreeze additives. The disadvantage of all these methods of concreting extended structures is the need for additional material and energy costs for heating the frozen foundation on which the concrete is laid, as well as for creating normal temperature and humidity conditions for concrete hardening.

 A known method for the production of concrete structures in the factory by impregnating a cement-sand mixture with water under vibration (see ed. St. N 238384 "Method of concreting concrete and reinforced concrete products". N.V. Mikhailov, G.M. Khutortsov, A. V. Borisov), as well as the method of concreting monolithic structures (see A.S. N 591570 "The method of concreting monolithic structures." A.D. Kozlov, B.A. Krylov, A.V. Lagoyda, V.P. Vetrov , V.M. Mikhaylichenko and V.S. Isaev), which consists in laying on a frozen foundation before concreting the dry layer construction concrete mix in order to improve the quality of the concrete structure. These technologies make it possible to obtain more durable and dense concretes in comparison with concretes made according to traditional technology, due to obtaining a “contact” structure of concrete, as well as a more dense laying of its components. The disadvantage of these methods of concreting structures is the use of sophisticated technological equipment, as well as the limited thickness of the sprayed layer of dry concrete mix (up to 10 cm).

 The closest technical solution is the method of separate concreting (see P.V. Protsenko. Vibro-discharge method of separate concreting. Concrete and reinforced concrete, N 12. - M, 1965. - p. 3-5), including the installation of formwork, laying, distribution and compaction of coarse dense aggregate in the installed formwork, injection of the laid layer of coarse dense aggregate with a vibroactivated cement-sand mortar.

 However, when using this method for concreting structures in the winter, it is necessary to incur significant additional material costs for heating the frozen foundation and creating normal temperature and humidity conditions for a set of concrete strengths of a given strength to be set.

The essence of the method of concreting "dry hot thermos" is that in the installed insulated formwork is placed aggregate - expanded clay with a temperature of 200-300 ^o C, which is distributed and compacted in the formwork, then after cooling the expanded clay to a temperature below 100 ^o C it is injected with cement -Sand mortar with expanded clay fixation using special loading and injection equipment, followed by a temporary warming of the concrete structure.

Hot expanded clay is delivered to the construction site in insulated containers from the manufacturer, where it is taken from the “refrigerator” of the furnace with a temperature that depends only on heat loss during transportation and on environmental conditions. Due to this, the production of expanded clay with a temperature of 200-300 ^o C at the construction site does not require additional energy costs, and also addresses the environmental problem of utilizing the heat of the cooled expanded clay at the plants for its production.

 The proposed method of winter concreting - "dry hot thermos" is illustrated by drawings of sections of the concrete structure on the example of the device of the underlying slab structures of high-speed railways, where: FIG. 1 - stage of laying, distribution and compaction of hot expanded clay in insulated formwork; FIG. 2 - stage of injection of cooling hot expanded clay with its fixations; FIG. 3 - stage - insulation of the concrete structure.

In the formwork 1, a layer of hot expanded clay 3 with a temperature of 200-300 ^o C is laid on the frozen base 2, after the expanded clay has cooled to a temperature below 100 ^o C, it is injected with cement-sand mortar using load-injection equipment 4, then a temporary insulation of the concrete structure follows 5 with insulation 6.

 The proposed method of winter concreting "dry hot thermos" includes the following technological operations.

In the installed position, the insulated formwork 1 is laid directly on the frozen base 2, a layer of hot expanded clay 3 with a temperature of 200-300 ^o C, which is distributed and compacted in the formwork, then after cooling the hot expanded clay to a temperature below 100 ^o C, the layer is injected with cement-sand mortar with claydite fixation using special loading and injection equipment 4. After that, if necessary, a temporary insulation of the concrete structure 5 is made using insulation spruce 6. The frozen base 2 is heated due to the heat of the cooling hot expanded clay. The creation of normal temperature and humidity conditions for a set of concrete structures of a given strength is achieved due to the heat of the cooling hot expanded clay and the exothermic heat release of cement accompanying the hardening of concrete.

Claims (1)

Winter concreting method "dry hot thermos", including the installation of insulated formwork, laying and compacting coarse aggregate, injection with cement-sand mortar, characterized in that expanded clay is used as coarse aggregate with a temperature of 200 - 300 ^o C, which is kept and injected after compaction cement-sand mortar after the expanded clay reaches a temperature below 100 ^o C, after which temporary insulation of the concrete structure is carried out.

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