Reinforced concrete ceiling and process for the manufacture thereof

Abstract

A reinforced concrete ceiling is characterized by a combination of the following features: a concrete slab ( 1 ) the thickness (D) of which falls short of the total thickness of the reinforced concrete ceiling, and intersecting ribs ( 2 ) which are each connected with an end region ( 3 ) to the concrete slab ( 1 ) in a force-transmitting manner and project freely upwards from the concrete slab ( 1 ), i.e., without being integrated in a further supporting surface structure, wherein their top end regions ( 4 ) are designed to absorb compressive and/or tensile forces and wherein the ribs ( 2 ) are connected to each other in a frictional manner at the respective intersection points ( 9 ), and their regions lying in each case between the top and bottom end regions ( 3,4 ) have at least one aperture ( 6 ).

1 . A planar concrete supporting structure, in particular a reinforced concrete supporting structure such as a reinforced concrete ceiling, characterized by a combination of the following features:
 a concrete slab ( 1 ) the thickness (D) of which falls short of the total thickness of the concrete supporting structure, and   intersecting ribs ( 2 ) which are each connected with an end region ( 3 ) to the concrete slab ( 1 ) in a force-transmitting manner and project freely upwards from the concrete slab ( 1 ), i.e., without being integrated in a further supporting surface structure, wherein their top end regions ( 4 ) are designed to absorb compressive and/or tensile forces and wherein the ribs ( 2 ) are connected to each other in a frictional manner at the intersection points ( 9 ), namely at least with their top end regions ( 4 ), and   their regions lying in each case between the top and bottom end regions ( 3 , 4 ) have at least one aperture ( 6 ).   
   
   
       2 . A concrete supporting structure according to  claim 1 , characterized in that ribs ( 2 ) are designed in the style of a framework structure, namely with a top chord ( 5 ) and diagonals ( 12 ) starting from the top chord ( 5 ) which are directly or indirectly connected via a bottom chord to the concrete slab ( 1 ) in a force-transmitting manner. 
   
   
       3 . A concrete supporting structure according to  claim 1 , characterized in that an all-over web ( 11 ) connecting the top end region ( 4 ) with the bottom end region ( 3 ) of the ribs ( 2 ) is provided with at least one aperture ( 6 ). 
   
   
       4 . A concrete supporting structure according to  claim 1 , characterized in that at least the top end region ( 4 ) of the ribs ( 2 ), optionally also the bottom end region ( 3 ) of the ribs ( 2 ), is provided with a reinforcement, in particular made of steel ( 13 ). 
   
   
       5 . A concrete supporting structure according to  claim 1 , characterized in that ribs ( 2 ) with diagonals ( 12 ), preferably formed from steel pipes, are provided. 
   
   
       6 . A concrete supporting structure according to  claim 1 , characterized in that ribs ( 2 ) having at least a top end region ( 4 ) made of high-strength or ultrahigh-strength concrete, preferably of concrete with a compressive strength of from 60 to 250 N/mm 2 , are provided. 
   
   
       7 . A concrete supporting structure according to  claim 1 , characterized in that ribs ( 2 ) are connected in a frictional manner to the concrete slab ( 1 ) using in-situ concrete. 
   
   
       8 . A concrete supporting structure according to  claim 1 , characterized in that a web of the ribs ( 2 ) as well as optionally a top chord ( 5 ) or a bottom chord, respectively, are made of steel. 
   
   
       9 . A concrete supporting structure according to  claim 1 , characterized in that a top chord ( 5 ) of the ribs ( 2 ) is formed from a steel profile ( 14 ) filled with concrete. 
   
   
       10 . A concrete supporting structure according to  claim 1 , characterized in that the concrete slab ( 1 ) exhibits at last one layer of high-strength, preferably ultrahigh-strength, concrete. 
   
   
       11 . A concrete supporting structure according to  claim 10 , characterized in that the concrete slab ( 1 ) exhibits a steel reinforcement, a textile reinforcement or a fibre reinforcement. 
   
   
       12 . A concrete supporting structure according to  claim 1 , characterized in that the concrete slab ( 1 ) is formed from a thin semifinished plate ( 1 ′,  1 ″) made of reinforced concrete on which a planar reinforcement ( 13 ) is applied and which is grouted with the semifinished plate ( 1 ′,  1 ″) with in-situ concrete ( 16 ), with the bottom end regions ( 3 ) of the ribs ( 2 ) being integrated simultaneously. 
   
   
       13 . A concrete supporting structure according to  claim 1 , characterized in that the total height of the concrete supporting structure ranges between 12 and 120 cm, preferably between 20 cm and 50 cm. 
   
   
       14 . A concrete supporting structure according to  claim 1 , characterized in that the thickness (D) of the concrete slab ( 1 ) ranges between 4 cm and 40 cm, preferably between 8 cm and 20 cm. 
   
   
       15 . A concrete supporting structure according to  claim 1 , characterized in that the concrete slab ( 1 ) is integrally connected with the rib or ribs ( 2 ), respectively, as a finished part. 
   
   
       16 . A concrete supporting structure according to  claim 15 , characterized in that several prefabricated concrete slabs ( 1 ) are connected with their ribs to a concrete supporting structure, with grouting joints and prestressing elements ( 15 ) being provided for the connection. 
   
   
       17 . A concrete supporting structure according to  claim 16 , characterized in that the prestressing elements ( 15 ) in the ribs ( 2 ) and in the concrete slabs ( 1 ) are in each case provided in the tensile zones. 
   
   
       18 . A concrete supporting structure according to  claim 1 , characterized in that the concrete slab ( 1 ) comprises at least two semifinished plates ( 21 ) arranged directly next to each other which are covered by a reinforced topping layer of concrete ( 22 ) and are interconnected in a frictional manner. 
   
   
       19 . A concrete supporting structure according to  claim 18 , characterized in that the ribs ( 2 ) rest with base parts ( 3 ) on the semifinished plates ( 21 ), with the base parts ( 3 ) being circumferentially enclosed by the topping layer of concrete ( 22 ). 
   
   
       20 . A concrete supporting structure according to  claim 18 , characterized in that the reinforcement ( 23 ) of the topping layer of concrete ( 22 ) penetrates the apertures ( 6 ) of the ribs ( 2 ). 
   
   
       21 . A concrete supporting structure according to  claim 18 , characterized in that the base parts ( 3 ) of the ribs ( 2 ) are anchored in the topping layer of concrete ( 22 ) via a reinforcement ( 25 ). 
   
   
       22 . A concrete supporting structure according to  claim 18 , characterized in that the base parts ( 3 ) of the ribs ( 2 ) are anchored in the semifinished plates ( 21 ) via a reinforcement ( 25 ). 
   
   
       23 . A concrete supporting structure according to  claim 22 , characterized in that the ribs ( 2 ) and the semifinished plates ( 21 ) have a common reinforcement ( 25 ). 
   
   
       24 . A concrete supporting structure according to  claim 23 , characterized in that the ribs ( 2 ) along with a semifinished plate ( 21 ) are designed as a semifinished product. 
   
   
       25 . A concrete supporting structure according to  claim 18 , characterized in that the apertures ( 6 ) of the ribs ( 2 ) diverge from above to below. 
   
   
       26 . A concrete supporting structure according to  claim 18 , characterized in that the apertures ( 6 ) of the ribs ( 2 ) converge from above to below. 
   
   
       27 . A concrete supporting structure according to  claim 18 , characterized in that a slab element resting on a support is provided above the support ( 8 ), wherein ribs ( 29 ) extending radially outwards in a star-shaped manner from a centre, which ends up lying above the support ( 8 ), are provided, which ribs are attached to ribs ( 2 ) of adjacent elements on the edge side of the slab element. 
   
   
       28 . A concrete supporting structure according to  claim 27 , characterized in that the ribs ( 29 ) extending in a star-shaped manner are provided with a reinforcement which is attached to a reinforcement ( 27 ) of adjacent elements or changes into the reinforcement of adjacent elements. 
   
   
       29 . A concrete supporting structure according to  claim 27 , characterized in that ribs ( 29 ) extending in a star-shaped manner are connected to ribs extending in the peripheral direction of the slab element. 
   
   
       30 . A concrete supporting structure according to  claim 18 , characterized in that the topping layer of concrete ( 22 ) is statically contributive, with its reinforcement ( 23 ) extending beyond a semifinished plate ( 21 ) to at least a second adjacent semifinished plate ( 21 ). 
   
   
       31 . A concrete supporting structure according to  claim 18 , characterized in that the thickness of the semifinished plate ( 21 ) ranges between 2 and 20 cm, preferably between 4 and 16 cm, and the thickness of the topping layer of concrete ( 22 ) ranges between 2 and 20 cm, preferably between 4 and 8 cm. 
   
   
       32 . A process for the manufacture of a concrete supporting structure according to  claim 1 , characterized in that formwork elements for forming the ribs ( 2 ) are placed on the concrete slab ( 1 ) and the concrete supporting structure is manufactured by installing a reinforcement ( 13 ) in the cavity provided for the ribs ( 2 ) between the walls of the formwork elements and by grouting said cavity with concrete ( 16 ). 
   
   
       33 . A process for the manufacture of a concrete supporting structure according to  claim 1 , characterized in that thin-walled plate-shaped elements are placed vertically on a reinforcement ( 13 ) applied to a semifinished plate ( 1 ′,  1 ″), a layer covering the semifinished plate ( 1 ′,  1 ″) is concreted and, subsequently, the space between the thin-walled plate-shaped elements is filled with concrete, with the ribs being formed. 
   
   
       34 . A process for the manufacture of a concrete supporting structure according to  claim 15 , characterized in that concrete slabs ( 1 ) are manufactured integrally with ribs ( 2 ) as finished parts (F′, F″) which are interconnected after transport to a construction site, preferably by grouting joints ( 20 ) and prestressing elements ( 15 ). 
   
   
       35 . A process for the manufacture of a concrete supporting structure according to  claim 18 , characterized in that the semifinished plates ( 21 ) are produced in a factory for prefabricated parts along with rib bodies ( 26 ) provided on them, wherein the rib bodies ( 26 ) have channels located at the top or are designed so as to be hollow, that said semifinished plates ( 21 ) are transported to the construction site and are placed there in correct position according to the building to be constructed, that subsequently a reinforcement ( 23 ) extending across at least two adjacent semifinished plates ( 21 ) is applied to the semifinished plates ( 21 ) and a reinforcement ( 27 ) extending into cavities of rib bodies ( 26 ) of adjacent semifinished plates ( 21 ) is provided in the cavities of the rib bodies ( 26 ), whereupon the topping layer of concrete ( 22 ) is applied and the rib bodies ( 26 ) are grouted with concrete.