EP3235967A1 - Bewehrte betonplatte, insbesondere eine bodenplatte und ein bodensystem - Google Patents

Bewehrte betonplatte, insbesondere eine bodenplatte und ein bodensystem Download PDF

Info

Publication number
EP3235967A1
EP3235967A1 EP16184512.8A EP16184512A EP3235967A1 EP 3235967 A1 EP3235967 A1 EP 3235967A1 EP 16184512 A EP16184512 A EP 16184512A EP 3235967 A1 EP3235967 A1 EP 3235967A1
Authority
EP
European Patent Office
Prior art keywords
slab
concrete
floor
reinforcement
flange
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP16184512.8A
Other languages
English (en)
French (fr)
Inventor
Magdalena Lis
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of EP3235967A1 publication Critical patent/EP3235967A1/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
    • E04B5/00—Floors; Floor construction with regard to insulation; Connections specially adapted therefor
    • E04B5/16—Load-carrying floor structures wholly or partly cast or similarly formed in situ
    • E04B5/32—Floor structures wholly cast in situ with or without form units or reinforcements
    • E04B5/36—Floor structures wholly cast in situ with or without form units or reinforcements with form units as part of the floor
    • E04B5/38—Floor structures wholly cast in situ with or without form units or reinforcements with form units as part of the floor with slab-shaped form units acting simultaneously as reinforcement; Form slabs with reinforcements extending laterally outside the element
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C3/00—Structural elongated elements designed for load-supporting
    • E04C3/02—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces
    • E04C3/29—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures
    • E04C3/293—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures the materials being steel and concrete
    • E04C3/294—Joists; Girders, trusses, or trusslike structures, e.g. prefabricated; Lintels; Transoms; Braces built-up from parts of different material, i.e. composite structures the materials being steel and concrete of concrete combined with a girder-like structure extending laterally outside the element
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C5/00—Reinforcing elements, e.g. for concrete; Auxiliary elements therefor
    • E04C5/01—Reinforcing elements of metal, e.g. with non-structural coatings
    • E04C5/06—Reinforcing elements of metal, e.g. with non-structural coatings of high bending resistance, i.e. of essentially three-dimensional extent, e.g. lattice girders
    • E04C5/065—Light-weight girders, e.g. with precast parts
    • E04C5/0653—Light-weight girders, e.g. with precast parts with precast parts
    • E04C5/0656—Light-weight girders, e.g. with precast parts with precast parts with lost formwork

Definitions

  • the invention relates to a reinforced concrete slab, especially a floor slab and a floor system.
  • the solution according to the invention is widely applicable in the construction industry.
  • the Polish patent number P. 173278 discloses a solution of a composite beam and block floor constituted by a thin large-size prefabricated reinforced concrete slab provided with a reinforcement protruding above its upper surface in the form of spatial trusses, running parallel to the span of the floor, and by inverted prefabricated reinforced concrete hollow core roof slabs arranged between these trusses, provided with outwardly protruding transverse and longitudinal reinforcement.
  • the spaces between the hollow core roof slabs are filled with concrete, wherein the concrete in the spaces extending along the floor constitutes, together with the upper part of the hollow core roof slabs, supporting ribs of the structure.
  • the whole structure is reinforced with a support reinforcement arranged in the supporting ribs of the structure.
  • the Polish patent number P. 166681 discloses a solution of a thin-walled reinforced concrete prefabricated floor slab, designed particularly for floors bending in two directions consisting of a reinforced concrete slab and protruding stiffeners in the shape of trusses with a triangular cross-section, whose lower zones are embedded in concrete and by upwardly protruding steel reinforcement loops arranged along the longitudinal edge of the concrete slab.
  • the Polish patent number P. 217612 discloses a solution of a prefabricated reinforced concrete slab equipped with grating supports and v-diverging slots along the lateral edges of the slab, additionally reinforced with concentrated connecting rods, which, after being filled with concrete topping, form a dowel connector.
  • the Polish patent number P. 402760 discloses, in turn, a solution of a steel and concrete beam to reinforce construction prefabricated units with a preferred ratio of weight per unit of their length.
  • the beam according to this solution comprises a multi-rod openwork spatial reinforcement in the form of a truss located inside a concrete block shaped in the form of a solid, where the spatial steel reinforcement truss is equipped, in the upper part, with a special concrete form shaped in such a way that between the lower and the upper surface of the prefabricated floor, a free space is created.
  • Beam and block floors are formed by a combination of reinforced concrete floor beams and hollow blocks filling the spaces between the beams. Generally, spacing of the beams does not exceed 90 cm, and most often it is between 40 and 60 cm. Between the beams, fillings are arranged, which may be constituted by hollow blocks of ceramics, gravel and concrete, slag and concrete, crushed-brick concrete, lightweight concrete, foam polystyrene, plaster, etc.
  • the upper part of the beam and block floor is a concrete slab made on site - topping concrete. It protects the hollow blocks against damage and is an underlay for the floor.
  • the slab has a thickness of 3-7 cm.
  • the total thickness of the floor is approx. 23-35 cm and depends on the thickness of the slab and on the height of the hollow blocks.
  • the greatest disadvantage of the solution of this type is time and labour consumption resulting from the number of elements used in this floor. For example, per 100 m2 of a beam and block floor, approx. 700 elements, hollow blocks with dimensions of 25x50 cm and average weight of 15 kg, need to be arranged (which totals approx. 10t of manually arranged hollow blocks, in addition, it is necessary to previously arrange beams). Furthermore, the number of elements requiring to be arranged on the construction site makes the very process of installing this type of solution very dangerous. Workers working at the construction of a floor must take special care, they can move only through narrow beams supported on the walls of the building and watch out for the spaces between them. An additional disadvantage of this type of building material is its low sound insulation, which tends to be particularly bothersome to the users of the building.
  • Filigree is a stay-in-place formwork slab comprising longitudinal and transverse supporting reinforcement and embedded trusses allowing transport of slabs.
  • Filigree slabs are always individually designed to measure of the building, their production and assembly requires close cooperation with the designer. In case of potential defects of the resulting slab, or of a misestimation of its dimensions, it is necessary to produce it again.
  • the solution of this type of a slab cannot be cropped or otherwise adapted to the building on the construction site.
  • reinforcement of floor tie beam is performed and an additional reinforcement of floor in the form of basic reinforcement of the structure or additional reinforcements in connection places of slabs is arranged.
  • a layer of concrete topping is poured, and the arranged slabs function as a formwork.
  • the primary objective of the invention described in this document was to eliminate the disadvantages of known solutions indicated above.
  • the invention makes it possible to quickly obtain a durable floor without having to incur high time investment, as in the case of beam and block floors, or financial investment, as required by the transport and installation of filigree slabs.
  • improved parameters of bearing capacity and sound insulation compared to beam and hollow block floors are obtained.
  • An additional advantageous feature is the ease and quickness of assembly, which significantly contributes to reducing the costs of making a floor.
  • the solution according to the invention combines features of known solutions, making appropriate innovative improvements.
  • a significant feature of the claimed solution is the possibility of prefabrication of finished elements for stock, thanks to which orders for delivery of slabs according to the invention can be carried out immediately, with no need to wait for the production of elements.
  • the reinforced slab according to the invention consists of a concrete flange and of a steel truss protruding above the surface thereof, whose lower zones are embedded in concrete.
  • the concrete slab according to the invention has been equipped with a suitable reinforcement, combining the features of the reinforcement characteristic of beam and block floors with a reinforcement typical of filigree slabs.
  • the slab according to the invention in the basic version has a supporting reinforcement and an additional reinforcement.
  • the supporting reinforcement is constituted by at least one steel truss embedded in the slab.
  • the truss is arranged longitudinally to the plane of the slab and centrally to its width.
  • Elements of this reinforcement usually in the form of cross-braces, protrude above the top surface of the slab and extend in parallel to the span of the floor.
  • the slab can be equipped with additional reinforcement.
  • the additional reinforcement can be present in the form of steel or composite rods or wires or prestressing steel cables longitudinally arranged in the slab.
  • the slab can be equipped with a reinforcement of mesh made of steel or of artificial fibres. Both types of the additional reinforcement may also simultaneously be present in the slab.
  • the essence of the slab according to the invention is also its dimensions. Generally, it is desirable that the height of the flange of the concrete slab was between 15 and 80 mm, and the width of the flange of the concrete slab ranged between 15 and 80 cm. A slab ranging between these dimensions best performs its functions, also from the perspective of the assembly and transportation of finished slabs.
  • the concrete flange of the slab may have a variable height, if this parameter will be measured after embedding the supporting reinforcement in the surface of the slab.
  • the length of the concrete flange can be arbitrary.
  • a significant feature of the slab according to the invention is also that elements of foam polystyrene, flexible foam polystyrene or other lightweight sound-insulating and/or heat-insulating material can be arranged on the flange of the concrete slab. This feature allows for reducing the weight of the floor and improving its heat- and sound-insulating parameters.
  • the concrete flange of the slab can be made e.g. of materials such as concrete, polymer concrete, lightweight concrete or composite slab.
  • the essence of the slab according to the invention is also the possibility to suitably modify it on the construction site.
  • the solution according to the invention can also be e.g. arbitrarily cropped or punched on site, depending on demand. This allows for adapting the elements to the individual conditions of the building or to the requirements of the investor.
  • construction of a floor with the elements according to the invention is quicker and cheaper than construction of a floor with traditionally available solutions.
  • Floor of this type does not require individual designing for each room in which it is to be used. Neither does the solution according to the invention require using of heavy equipment when producing and installing particular elements of the floor.
  • the number of elements used in the construction of this type of floor was significantly reduced, which significantly reduced the time of installation of the floor.
  • Concrete slabs according to the invention are lightweight, modular and prefabricated, and simultaneously have the highest strength and sound insulation parameters.
  • the concrete slab according to the invention can also be used in the construction of other surfaces than the floor, e.g. retaining walls, foundations, etc.
  • the characteristics obtained in the slab according to the invention, such as its modularity, strength and relatively low weight provide broad opportunities for it to be used in construction industry.
  • Reinforcing the slab with a supporting and additional reinforcement contributes to the improvement of its bearing capacity, which in turn significantly improves the properties of the slab used e.g. in the construction of retaining walls. It is because the retaining wall transfers the pressure of the secured construction facility onto the substrate, so that the parameters of its bearing capacity are extremely important. Thanks to the solutions used, the slabs can form a retaining wall with exceptional strength and resistance to high static loads and environmental conditions.
  • the wall made of concrete slabs according to the invention is also simple, faster and cheaper to install than the traditional wall. Prefabricated units are set up quickly and easily, regardless of the weather.
  • the essence of the solution according to the invention is a reinforced concrete slab, in particular a floor slab, characterised in that it is a prefabricate unit and it has a supporting reinforcement in the form of at least one longitudinally arranged steel truss, and an additional reinforcement, wherein the height of the concrete flange of the slab is between 15 and 80 mm, and the width of the concrete flange of the slab is between 15 and 80 cm.
  • the slab according to the invention comprises an additional reinforcement, which is constituted by a longitudinal reinforcement.
  • the longitudinal reinforcement is in the form of steel and/or composite rods made of fibre glass or another polymer.
  • the longitudinal reinforcement is constituted by wires and/or prestressing steel cables.
  • the additional reinforcement is constituted by a mesh made of steel and/or of artificial and/or composite fibres embedded in the plane of the slab.
  • the concrete flange of the slab has a variable height in the transverse cross-section.
  • elements of foam polystyrene, flexible foam polystyrene or other lightweight sound-insulating and/or heat-insulating material are arranged on the flange of the slab.
  • the flange of the slab is made of concrete, polymer concrete, lightweight concrete or composite slabs.
  • the essence of the solution according to the invention is also a floor system, characterised in that it comprises at least one reinforced concrete slab which is prefabricate unit and which has a supporting reinforcement in the form of at least one longitudinally arranged steel truss, and an additional reinforcement, wherein the height of the concrete flange of the slab is between 15 and 80 mm, and the width of the concrete flange of the slab is between 15 and 80 cm.
  • fig. 1 represents a reinforced concrete slab
  • fig. 2 represents a concrete slab equipped with a steel truss with a supporting reinforcement
  • fig. 3 represents a concrete slab equipped with an additional longitudinal reinforcement
  • fig. 4 represents a concrete slab equipped with an additional reinforcement in the form of a mesh made of steel or of artificial fibres
  • fig. 5 represents a concrete slab equipped with an additional longitudinal reinforcement and in the form of a mesh made of steel or of artificial fibres
  • fig. 6 represents elements of foam polystyrene or other lightweight material.
  • a reinforced concrete slab 1, in particular a floor slab, comprises a supporting reinforcement 2 in the form of axially symmetrically arranged steel truss and an additional reinforcement 3 in the form of three longitudinally arranged steel rods 3a.
  • the slab may comprise an additional reinforcement 3 in the form of a mesh 3b made of steel or artificial fibres.
  • the additional reinforcement 3 is made in the form of longitudinal rods 3a and a mesh 3b, which may be a mesh made of steel, of polymers or of other artificial fibres.

Landscapes

  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Composite Materials (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Bridges Or Land Bridges (AREA)
  • Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)
  • Panels For Use In Building Construction (AREA)
EP16184512.8A 2016-04-22 2016-08-17 Bewehrte betonplatte, insbesondere eine bodenplatte und ein bodensystem Withdrawn EP3235967A1 (de)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PL416945A PL416945A1 (pl) 2016-04-22 2016-04-22 Zbrojona płyta betonowa, zwłaszcza stropowa oraz system stropowy

Publications (1)

Publication Number Publication Date
EP3235967A1 true EP3235967A1 (de) 2017-10-25

Family

ID=56740895

Family Applications (1)

Application Number Title Priority Date Filing Date
EP16184512.8A Withdrawn EP3235967A1 (de) 2016-04-22 2016-08-17 Bewehrte betonplatte, insbesondere eine bodenplatte und ein bodensystem

Country Status (3)

Country Link
EP (1) EP3235967A1 (de)
PL (1) PL416945A1 (de)
UA (1) UA144242U (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108643428A (zh) * 2018-05-23 2018-10-12 中铁建设集团有限公司 一种可调节高度的装配式预制混凝土叠合楼板
CN108643429A (zh) * 2018-05-23 2018-10-12 北京工业大学 一种可调节高度的装配式叠合楼板
CN108661224A (zh) * 2018-05-23 2018-10-16 中铁建设集团有限公司 一种可调节高度的装配式混凝土叠合楼板
CN110258884A (zh) * 2019-06-12 2019-09-20 湖南固可得建筑科技有限公司 一种防火组合楼承板
CN110847479A (zh) * 2018-11-09 2020-02-28 张波 用于制作建筑墙体的预应力桁架板及其制作的建筑墙体
CN111663694A (zh) * 2020-06-30 2020-09-15 广东珠江建筑工程设计有限公司 一种装配式建筑叠合板

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1804703A1 (de) * 1968-10-23 1970-05-27 Schwarz & Meissner Gmbh Vorgefertigte Bewehrung fuer Stahlbetonbretter
US3885369A (en) * 1973-03-08 1975-05-27 Vigarex Ets Structural element
DE9417777U1 (de) * 1994-11-05 1995-01-05 Dausend, Hans-Werner, 42289 Wuppertal Kragplattenanschlußelement
PL166681B1 (pl) 1991-04-26 1995-06-30 Przed P Uslugowe Unidom Sp Z O Cienkościenna żelbetowa prefabrykowana płyta stropowa, zwłaszcza dla stropów dwukierunkowo zginanych
PL173278B1 (pl) 1994-04-07 1998-02-27 Politechnika Czestochowska Zespolony stropgęstożebrowy
EP1908891A2 (de) * 2006-07-06 2008-04-09 Ingenieria de Prefabricados S.L. Verbundplate für Betonboden
PL402760A1 (pl) 2013-02-14 2014-08-18 Andrzej Meronk Belka stalowo-betonowa do zbrojenia prefabrykatów budowlanych
PL217612B1 (pl) 2009-09-09 2014-08-29 Politechnika Warszawska Płyta prefabrykowana z dźwigarkami kratowymi

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1804703A1 (de) * 1968-10-23 1970-05-27 Schwarz & Meissner Gmbh Vorgefertigte Bewehrung fuer Stahlbetonbretter
US3885369A (en) * 1973-03-08 1975-05-27 Vigarex Ets Structural element
PL166681B1 (pl) 1991-04-26 1995-06-30 Przed P Uslugowe Unidom Sp Z O Cienkościenna żelbetowa prefabrykowana płyta stropowa, zwłaszcza dla stropów dwukierunkowo zginanych
PL173278B1 (pl) 1994-04-07 1998-02-27 Politechnika Czestochowska Zespolony stropgęstożebrowy
DE9417777U1 (de) * 1994-11-05 1995-01-05 Dausend, Hans-Werner, 42289 Wuppertal Kragplattenanschlußelement
EP1908891A2 (de) * 2006-07-06 2008-04-09 Ingenieria de Prefabricados S.L. Verbundplate für Betonboden
PL217612B1 (pl) 2009-09-09 2014-08-29 Politechnika Warszawska Płyta prefabrykowana z dźwigarkami kratowymi
PL402760A1 (pl) 2013-02-14 2014-08-18 Andrzej Meronk Belka stalowo-betonowa do zbrojenia prefabrykatów budowlanych

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108643428A (zh) * 2018-05-23 2018-10-12 中铁建设集团有限公司 一种可调节高度的装配式预制混凝土叠合楼板
CN108643429A (zh) * 2018-05-23 2018-10-12 北京工业大学 一种可调节高度的装配式叠合楼板
CN108661224A (zh) * 2018-05-23 2018-10-16 中铁建设集团有限公司 一种可调节高度的装配式混凝土叠合楼板
CN108661224B (zh) * 2018-05-23 2020-10-16 中铁建设集团有限公司 一种可调节高度的装配式混凝土叠合楼板
CN110847479A (zh) * 2018-11-09 2020-02-28 张波 用于制作建筑墙体的预应力桁架板及其制作的建筑墙体
CN110258884A (zh) * 2019-06-12 2019-09-20 湖南固可得建筑科技有限公司 一种防火组合楼承板
CN111663694A (zh) * 2020-06-30 2020-09-15 广东珠江建筑工程设计有限公司 一种装配式建筑叠合板
CN111663694B (zh) * 2020-06-30 2021-04-02 广东珠江建筑工程设计有限公司 一种装配式建筑叠合板

Also Published As

Publication number Publication date
UA144242U (uk) 2020-09-25
PL416945A1 (pl) 2017-10-23

Similar Documents

Publication Publication Date Title
EP3235967A1 (de) Bewehrte betonplatte, insbesondere eine bodenplatte und ein bodensystem
EP3115523B1 (de) Betonplatte, insbesondere für verbundböden, und ein verbundboden
EP2848750B1 (de) Verfahren zum in-situ-giessen einer zementplatte mit stahldrahtgeflecht mit einem gespleissten rahmen und hängender schalung
EP2021555B1 (de) Betonträger
DK2379821T3 (en) Reinforced concrete piece
EP1350898A1 (de) Herstellungsverfahren einer leichteren alveolarplatte, eine solche platte und die verwendung einer solchen platte für die konstruktion von häusern
US6755001B2 (en) Suspended concrete flooring system and method
EP1908891A2 (de) Verbundplate für Betonboden
WO2011021151A1 (en) Method and system for in-situ construction of civil structures
ITMI20091693A1 (it) Pannello nervato prefabbricabile a posa orizzontale, verticale o inclinata.
US20130266793A1 (en) Building panels
EP0693597A1 (de) Modulares Dübelsystem zur Befestigung eines Verkleidungselementes an einer Kunststoffschaumplatte und Konstruktionselement mit diesem System
WO2011012974A2 (en) Method for manufacturing a precast composite steel and concrete beam and a precast composite steel and concrete beam made according to said method
US20090301011A1 (en) Reinforced concrete ceiling and process for the manufacture thereof
EP2402525A1 (de) Verfahren zur errichtung eines gebäudes mit einem vor ort gegossenen rahmen und dekorativer aussenverarbeitung
JP5532468B1 (ja) スラブ内の型枠支持部材
AU2016282066B2 (en) A structural building panel and a method of constructing a building
KR101701416B1 (ko) 장경간 슬래브용 프리캐스트 콘크리트 데크 및 이를 이용한 슬래브
CN211735984U (zh) 装配式预制叠合楼板和装配式叠合楼板
EP3719229A9 (de) Betonbodenplatte, herstellungsverfahren für diese platte und boden bestehend aus dieser platte
CN213682824U (zh) 一种轻质楼面墙体板组合结构体及其轻质楼面墙体板
CN115262835B (zh) 一种短出筋桁架钢筋混凝土叠合板的建造方法及连接结构
CN214090532U (zh) 一种预制混凝土带肋底板
KR100966011B1 (ko) 슬라브용 구조물
EP1801303A2 (de) Verbessertes Bauelement und Verfahren zur Herstellung

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20180425

RBV Designated contracting states (corrected)

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20201123

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20210407