Technical Field

The present invention relates to a type of steel reinforcement structure of bubbledeck element, and more particularly, to the steel reinforcement structure of a bubbledeck element and procedure for manufacturing bubbledeck element using this steel reinforcement structure with prominent features like lower cost, saving labor force and easy to execute.

Background Art

Nowadays, bubbledeck elements are widely applied all over the world in civil construction field especially in multi-storey buildings because it has many advantages in comparison with the normal solid concrete deck. The hollow deck saves up to 30- 40% the amount of steel and 40-50% the quantity of concrete as compared to solid concrete deck thank to using hollow plastic bodies for replace unnecessary concrete amount. However, the steel structure of bubbledeck element is complicated, costs much time and money for installation work because connecting steel reinforcement bars and hollow plastic bodies is quite difficult. Moreover, it raises some doubts about construction technical problems and execution matters.

Fig.l is the perspective drawing showing the structure of a normal bubbledeck slab element (10) illustrated in European patent No 166462 characterized in that upper steel mesh (11) and lower steel mesh (12) and many hollow spherical plastic bodies (13) are fixed to hold lower steel mesh (11) and upper steel mesh (12) by using a number of spacer to weld in to steel mesh to keep hollow bodies tight. A concrete deck is manufactured by this technical method, however; till remains some disadvantages as follows:

(1) Fitting of hollow plastic bodies in between lower steel mesh and upper steel mesh is always done in high position where a bubbledeck is casted, productivity of engineers and workers thus is being reduced much at the same time costing more time due to travel up and down or in case of casting concrete deck covered thousand square meter

(2) Costing much money for building formwork system; (3) Requiring specialized welding machines and much time to weld spacers to connect lower and upper steel mesh. Moreover, structure with too much welding joints may change the properties of steel and reduce the durability of deck structure; and:

(4) Because spherical plastic bodies are hollow, these plastic bodies will float on to the surface as pouring concrete causing thrust and unstable structure.

Fig.2 is perspective drawing showing another structure of normal bubbledeck (20) illustrated in international patent No 172307 issued in 1998 characterized in that thin concrete layer (21) of planned dimension in accordance with span of construction work, upper steel mesh (22) and lower steel mesh (23) and many hollow plastic bodies

(24) are fixed in between upper (22) and lower steel mesh (23) by using many spacers

(25) and stiffeners (26). This concrete deck structure of this technical method reveals some disadvantages as follows:

(1) Costing much money for building of factories or workshop to manufacture deck elements;

(2) Costing much money for transport these structures to construction sites< Besides, the thin concrete layer may be broken during transportation;

(3) Because hollow concrete deck structure is heavy, It is essential to use huge capacity crane to lift these structure to the planned position and it is also very difficult for crane to access the desired position;

(4) Costing more steel used to fabricate stiffeners which are used to move and lift deck structure;

(5) Due to the thin concrete layer is not at the same time casted with the concrete casted at construction sites, thus there is no integrity between them. This reduces technical efficiency and durability of bubbledeck elements.

For the above disadvantages, it is essential to introduce another bubbledeck element which is simpler, lighter, more stable to save material and easier to execute on sites.

Disclosure of the Invention

The purpose of the invention is to introduce a hollow concrete deck element structure which is easy to execute, saving time, not require much labor force till yet produce high robustness of deck element. To obtain the above target, the invention suggests that the steel reinforcement structure of bubbledeck must be characterized in that an upper steel mesh consisting of many steel plates which are connected with each other by welding or joining to produce mesh of square fabric spacing with designed dimension; lower steel mesh is laid under hollow plastic bodies in parallel with upper steel mesh consisting of many steel plates which are connected with each other by welding or joining to produce mesh of square fabric spacing with fabric spacing size equal to the size of ones in upper steel mesh; many hollow plastic bodies of spherical or of similar shapes. Each ball shall be fixed in between a grid cell of upper mesh and corresponding one of lower mesh at the position of 1 cell gap in horizontal and vertical direction; many connection bars to connect upper and lower steel mesh in 2 ways and 4 directions to hold tight the balls in order to creating a diagonal reinforcement link structure; formwork structure is fixed tight to bottom steel reinforcement consisting of many connectors located in to grid cells of 3 cell gap in one range and in offset position in 2 adjacent range of grid cell of 2 cell range gap, and many formwork plates of designed dimension which also can be removed or fixed by using bolts and nuts..

According to the invention, each connector is figured as a flat bar consisting of the first inclined gap at one end of the connector which plays the role of rebar ring fited to steel plate of a grid cell where no plastic ball of lower steel mesh is fixed and the second inclined gap formed at the remaining end of connectors where remains boss/lug. The boss/lug is formed at a lateral edge of second inclined gap and is in perpendicular to the surface of connectors, then to be fit into skew angle of corresponding grid cell where no hollow plastic bodies of upper steel mesh is fixed and the boss/lug of the second inclined gap is bent 90° to hold tight connectors. Adjacent connectors are arranged one after another in A-shape and many A-shape in series form a sinuous connection range along the longest side of steel reinforcement structure.

As per the invention, steel reinforcement structure of bubbledeck element also consists of some connectors located in perpendicular to the range of sinuous connection bars at appropriate positions to anchor upper steel mesh and lower steel mesh. According to the invention, each part of formwork system is formed by a part of first plane and a part of second plane. The second plane is in perpendicular to the first one, where the width of the first plane is equal to the outer width of each grid cell in lower steel mesh and the height of first plane is bigger than 2 times of diameter of steel plate in lower steel mesh. Two open channels formed at lateral edge of each end of the first plane, possess the same depth and the same width as the diameter of steel bars of lower steel mesh. The part of second plane has bolts holes to fix bolts in order to connect the formwork plates to the second plane part of connected element.

As per method presented in the invention, connectors are made of steel, hard plastic or wood; formwork parts may be made from metal sheet or laminated wood. The formwork plate consists of many tap-hole where equipped with machines to tap holes of internal thread and bolt holes to fix bolts in order to connect formwork plates to the second plane.

As per the suggestion of the invention, the manufacture procedure of hollow concrete deck has following steps: (stepl) manufacturing the steel reinforcement structure of bubbledeck elements namely: preparation of plan for assembling of deck structure, preparation of essential parts as per drawings and as per identification number; preparation of formwork plates equipped with tapped holes and internal thread bolt holes at designed positions; preparation of work platform of 1.2 meter height and bigger than the circumference of deck element; install purlin in the direction of short edge of slab with the beat distance is 0.7m; locate the formwork plates on the work platform to form the bottom of concrete deck; connect lower steel mesh to formwork plates using connectors which are fit tight to formwork plates using bolts and nuts via holes of connectors and bolt holes of formwork plates, where bolt heads are fixed on the connector and nuts are fixed on bottom surface of formwork plates; arrange hollow plastic bodies in to grid cell of lower steel mesh at the locations of one open cell distance in horizontal and vertical directions; arrange upper steel mesh on the surface of plastic ball layer; fit connectors to connect lower and upper steel mesh in order to create a diagonal connection system; numbering the deck elements and sorting them followed the instructions, (step 2): steel reinforcement installation namely: lifting or hoisting the steel reinforcement of bubbledeck elements into the designed positions; checking supporting beam, fixing anchors for safety purpose in case of hostile weather; (step3): preparation before casting the concrete namely: putting connection bars and reinforcement steel as designed, finishing formwork system, adjusting steel mesh and hollow plastic bodies, checking the purlin/supporting beam; (step 4): concrete casting namely: pouring concrete normally and checking supporting beam; (step 5): inspection after pouring concrete namely: inspecting the supporting beam, normally maintenance concrete, improve concrete intensify; and (step 6): finishing namely: remove the supporting beam, remove formwork plates using wench and finished over coating the slabs.

Advantageous Effect of the Invention

Thanks to using formwork system consisting of many connectors arranged in steel mesh and many formwork plates such as sheet metal, laminated wood or something similar fit into connectors that the weight of steel reinforcement structure of bubbledeck is reduced because of not using thin concrete layer as shown in known method. This also help to lift the structure up to high position much easier, to adapt well with assembling work on ground surface and to ensure the integrity of the concrete bulk for one-time concrete casting;

Due to the connection between formwork and other components of formwork systems of the invention using bolts and nuts. Therefore, the formwork can be removed for later uses after finishing hollow concrete deck;

By using such connectors to connect lower steel mesh and upper steel mesh, the structure can hold tight the hollow plastic bodies fixed between them. Moreover, it also helps the assembling work to be done much easier, especially in ground surface or inside the workshop in rainy days as well as in hot sunny days. It is no longer necessary to do assembling work in high position of building's upper storey covering thousands of square meters. This also saves much time for travel upwards and downwards during construction. Moreover, installation shall be carried out with high efficiency on ground surface, not in high position.

Detailed description shall be presented through methods showed in enclosed below drawings:

Brief Description of the Drawings The invention can be understood properly and comprehensively through detailed description and the illustrated drawings, where:

Fig.l is a perspective drawing shows steel reinforcement structure of normal bubbledeck element;

Fig.2 is a perspective drawings shows steel reinforcement structure of another normal bubbledeck element;

Fig.3A is a perspective drawings shows the steel reinforcement structure of bubbledeck element as characterized by this invention;

Fig.3B is the cross section level A-A in Fig.3A;

Fig.4A is perspective drawing shows connection bars as per the invention

Fig.4B is perspective drawing shows connection bars in which the boss is bended at the angle of 90°;

Fig.5 is a perspective drawing connectors as per the invention;

Fig.6 is a block diagram shows steps of manufacturing the hollow concrete deck structure as per the invention; and

Fig.7 is a perspective drawing show loose components of hollow concrete deck arranged in comply with procedure of manufacturing deck element of the invention.

Detailed Description of the Invention

Hereunder is the detailed description of priority methods as per the invention. This detail description aimed at showing common principles of the invention but unrestricted to all principles. The scope of invention is clearly defined through hereby enclosed claims.

The steel mesh structure of hollow concrete deck(lOO) consists of upper steel mesh (110) integrated in which many steel plate (111) joined together by welding or tie up together to make grid cells (112) of rectangular or square (square ones are better) of designed size; lower steel mesh (120) consists of many steel plates (121) joined together by welding or tie up to make grid cells (122) of rectangular or square (square ones are better) of designed size equal to the designed size of grid cell in the upper steel mesh (110) and in parallel with the corresponding upper steel mesh(l lθ); many hollow plastic bodies (130) are figured in spherical, discoidal, oval or similar shapes where each ball is fixed in between a cell (112) of upper steel mesh (110) and the corresponding cell (122) of lower steel mesh (120) in the positions of an open cell gap in horizontal and vertical direction; many connectors (140) to connect upper steel mesh (110) and lower steel mesh (120) to hold tight the balls (130) in between upper and lower steel mesh; formwork system (150) is mount to lower steel mesh (120).

As shown in Fig.l, Fig.2 and Fig.5, the connectors (140) are figured in flat bar consist of the first inclined gap (141) produced at one end of connectors (140) and its small end forms a rebar ring of designed size in order to fit totally and to anchor firmly to steel plates (121) of lower steel mesh (120), and the second inclined gap (142) formed at the remaining end of connectors (140) where remains boss/lug (1421). The boss/lug (1421) is formed at a lateral edge of second inclined gap (142) and is in perpendicular to the surface of connectors (140), where the boss/lug (1421) is bent as the second inclined gap (142) is fit into a steel plate (111) of the corresponding grid cell (112) of the upper steel mesh (110) to integrate into lower steel mesh (120). More detailed, the first inclined gap (141) of each connector (140) is fit into a steel plate

(121) of a random grid cell (122) where no hollow plastic bodies (130) of lower steel mesh (120) is fixed and the second inclined gap (142) of each connector (140) is fit into a steel plate (111) of above corresponding grid cell (112) where no hollow plastic bodies (130) of upper steel mesh (110) is fixed , in which steel plate (121) of grid cell

(122) and steel plate (111) of grid cell (112) are at skew angle to each other (resting on two diagonal sides of a cube), then the boss/lug (1421) of the second inclined gap (142) is bent 90° to hold tight connectors (140) with upper steel mesh (110), thus creating diagonal connection joint of connector (140). According to the invention, adjacent connectors (140) are arranged one after another in A-shape and many A- shape in series form a sinuous connection range along the longest side of steel reinforcement structure.

According to one aspect of the invention, 2 sinuous diagonal connecting rages of connection bars (140) separated by 3 ranges of hollow plastic bodies (130).

Steel reinforcement structure of bubbledeck as per the invention also consists of some connectors (140) located in open cells which are in perpendicular to the connection range of sinuous at appropriate positions to create diagonal bars at the remaining direction. Thus, steel reinforcement structure of the deck is connected tight in two ways and four directions.

As shown in Fig.3, each element 160 of the formwork system is structured in form of K panel and made of steel, rigid plastic or wood, including the first plane 161 and the second one 162 which is perpendicular to the first plane 161. The width of the first plane 161 is equal to the outside width of each cell 122 of the reinforcing mesh less than 120 and the height of the first plane 161 is twice as large as the diameter of the steel bar 121 of the reinforcing mesh less than 120; therefore, a gap between the reinforcing mesh less than 120 and the formwork panel 170 is made (as described below). Two open horizontal slots 161' are made from the side to inside each end of the first plane 161 and their width and depth are equal to the diameter of the steel bars 121 of the reinforcing meshes less than 120. The first plane 161 of the element 160 has the suitable shape in order that the use of materials for manufacturing is at minimal level; for example, there is an element cut in the middle of the first plane 161 as shown in Fig.4.

As shown in Fig.3 and Fig.4, the elements 160 are arranged in the cell 122 of the reinforcing mesh less than 120 at the positions in which the distance between them is three cells 122 in a line of vertical/horizontal cells 122 of the bottom reinforcing mesh and at the alternate positions in two neighboring horizontal/vertical cell lines in which the distance between them is 2 cell series. Here, two horizontal open slots 161' of the first plane 161 of the element 160 are fitted with two parallel steel bars 121 in each cell 122 and the first plane 161 of the element 160 should be perpendicular to the reinforcing mesh less than 120 or the second plane 162 is parallel with the reinforcing mesh less than 120 and the second plane 162 is parallel with and far from the reinforcing mesh less than 120 at a given distance (the height is larger than that of the first plane 161 and twice the diameter of the steel bar 121 of the reinforcing mesh less than 120).

As shown in Fig.4, the formwork panels 170 are made of sheet metal, plywood or the like which can be removable into the second plane 162 of the elements 160 using bolts and screws and including many pulle ports 1701 in which the pulles in the form of bolts 180 with threads inside and holes to install bolts 1702 are arranged in the given positions.

As show in Fig.8, the procedures of manufacturing the hollow concrete deck include the production of the reinforcing structure of the hollow concrete deck Sl, the installation of the reinforcement of the hollow concrete deck in the site S2, the preparation of pouring concrete S3, the pouring of concrete S4, the follow-up after the pouring of concrete S5 and the completion S6.

The steps of the production of the reinforcing structure of the hollow concrete deck Sl include: the preparation of plane for installing the structure of the deck; that of necessary elements according to the drawing and number sign; that of formwork panel 170 and the boring of the pulle port 1701 where the pulles in the form of bolt 180 with threads inside and holes for installing bolt 1702 are arranged in the given positions; the preparation of the false work with the height of 1.2m and the width larger than the circumference of the deck; the installation of purlin according to the direction of short side of the deck needed with the best distance of 0.7m; the arrangement of the formwork 170 on the false work using the parts 160, in which the bolts are installed through the hole 162' of the parts 160 and holes to install the bolt 1702 of the formwork 170 and at the same time installed with the screw on the bottom of the formwork 170; the arrangement of the hollow balls 130 into the cells 122 of the reinforcing mesh less than 120 at the distances of one hollow cell in the horizontal and vertical direction; the arrangement of the reinforcing mesh more than 110 on the hollow ball layer 130; the installation of the rebar 140 to connect the reinforcing mesh more than 110 and less than 120 to create an oblique connection system as described above; and the numbering of the elements and arrangement according to the guideline.

Next, the steps of the installation of the reinforcement of the hollow concrete deck in the site S2 include: lifting or winching the steel of the hollow concrete deck in the position designed; checking the support system; and safely anchoring for the weather prevention;

The steps of the preparation of pouring concrete S3 include: the installation of binding and reinforcing steel according to the design; the completion of the casing system; the adjustment of the reinforcing meshes more than 110 and less than 120 and hollow balls 130; and the re-check of the support system.

The next is the steps of the pouring of concrete S4, including the pouring and even arrangement of concrete; and the check of the support system.

The steps of the follow-up after the pouring of concrete S5 include: the follow- up of the support system, the maintenance of the normal concrete; and the enhancement of concrete.

Finally, the steps of the completion S6 include: removal of the support system; that of the formworks 170 using the pulles 190 installed in the pulles in form of bolt with internal thread to push the formwork 170 out of the concrete deck; and the completion by mortaring.

Industrial Applicability

Thanks to using the formwork system including many parts arranged into the bottom reinforcing mesh and many formworks such as sheet metal, plywood or the like installed into the parts with the reduced weight of the reinforcing structure of the hollow concrete deck due to using no the thin concrete deck as mentioned in the given solution, the lift is easily made, suitable with the installation on the ground, and ensuring the monolithic feature of concrete because the concrete pouring is made once;

Because of connection between the formworks with the parts in the formwork system of the invention using the screws, the formworks can be removed for reuse after completing the hollow concrete deck.

Thanks to using the bars to connect the upper reinforcing meshes with the bottom ones with many hollow balls arranged inside, the installation is done easily, especially it can be made on the ground and in the workshop in case of raining and sun, recovering the situation of lifting on the high floors and that of the pouring floors with thousands of square meters as well as reducing the time of moving by the workers on the high floors and bringing about the higher efficiency on the ground than on the high floor.

Although the invention is shown in the solutions and figures attached but it is necessary to claim that the invention is not limited by those solutions. The experts in this technical field acknowledged that it can still carry out many similar adjustments and supplements. For example, the bars can be structured in any form such as welding connection to weld the cross-bars by hoop-iron, round bars to connect the upper reinforcing mesh and bottom one. The joint strap can be structured in form of U with the U shaped flat bottom in order that the formwork can be installed using the screws and two U branches with the hook shaped ends to hook into two equivalent bars of each cell of the bottom reinforcing mesh. Therefore, the invention includes other equivalent adjustments and supplements in the scope of parts as in the Claims attached.