WO1997029252A1

WO1997029252A1 - Precast lightweight concrete halls construction system

Info

Publication number: WO1997029252A1
Application number: PCT/SI1997/000003
Authority: WO
Inventors: Ante Mihanovic; Boz^¿enko JELIC; Zdravko MES^¿TROVIC
Original assignee: DAMJANIC FRANO
Current assignee: DAMJANIC FRANO
Priority date: 1996-02-09
Filing date: 1997-01-17
Publication date: 1997-08-14
Anticipated expiration: 1998-08-09
Also published as: BA97262A; HRP960066B1; SI9720004A; AU1460397A; HRP960066A2

Abstract

The precast lightweight concrete system for the rapid construction of halls and buildings which consist of lightweight concrete columns, beams, roof and ceiling elements, and wall panels, is based on the principles of dry assembly with efficient finishing for the facades and ceilings. This system consists of the following elements: main roof beam (1), roof beam (2), roof valley (3), roof-ceiling slab (4), facade panels (5), columns (6), foundation beams (7) and precast foundations (8), where all these elements, by their dimensions and shapes, make a compatible system. Due to their composition and form, single elements of the system can be used separately or can be combined with other precast or monolithic systems. The regular form of the elements makes possible the application of different construction methods and buildings of various forms; thus, architects and engineers have greater creative freedom in hall and housing design.

Description

PRECAST LIGHTWEIGHT CONCRETE HALLS CONSTRUCTION SYSTEM

Technical field

The technical field is very well defined according to IPC subgroups E 04 B 1/00 and E 04 B 2/00 which contain general structures such as walls, ceilings, floors roofs and single elements.

Technical problem

This precast lightweight concrete halls construction system solves the following problems: quick and rational building, partial or complete precasting and a high level of rough work finishing. The adaptability of the system to different forms of halls and buildings by using a few types of precast elements contributes to rationality and has wide applicability.

State of the art

A general review of masonry structures shows that precast technology based on small precast elements has been known for a long time. In addition to the classical stone blocks and concrete and clay block technology, lightweight concrete block technology was developed at the end of the 19 century. At the beginning of the 20 th century (1907) The British Museum was built using lightweight concrete technology based on clinker concrete. In the mid 1930s, aerated concrete was introduced into Europe mainly in Sweden. After War World II the production and application of lightweight elements made of expanded clay, expanded shale, foamed slag, and pumice, expanded becoming lighter and automatically achieving better insulation properties especially the temperature insulation property. At the same time, compressive strength was similar or a bit lower than for normal weight concrete. Expanded polystyrene lightweight concrete, as a special type of lightweight concrete, was introduced into Germany in 1951. The existing lightweight concrete systems which solve, to a certain extent, the mentioned technical task are Leca (Germany), Lytag (Britain) and systems based on expanded clays such as Aglite (Britain), Gravelite (U.S.A.), Solite (Canada) and Liapor (Sweden).

There are no similar solution as those obtained by this patent in civil engineering The technical task of constructing large spans has been solved for lightweight concrete systems in different ways in the following cases:

(1 ) by using Aglite technology in a multi-storey building in London, ref.:

[1 ].

(2) by using Lytag technology as in the 60-storey Marina City Towers and Water Tower Plaza, the highest lightweight concrete building in the world, both in Chicago, ref.: [1].

(3) by using Leca technology in the BMW Office in Munich, ref.:[1].

The general concept of this patent is similar to the idea in the patent application

HP-P960052A.

Lightweight concrete as structural and isolation material is incorporated in the technical codes of all developed countries. A special treatment of these structures is proposed by ref.:[2].

References: [1] Short A., W. Kinniburgh, Lightweight Concrete, third edition, Applied

Science Publishers Ltd., London 1978. [2] Eurocode 2: Design of concrete structures - Part 1-4; General rules -

Lightweight aggregate concrete with closed structures, ENV 1992-1-

4:1994.

Essential Features of the Patent

The main feature of this patent is the application of the principle of complete reinforcement of lightweight concrete beams, as parts of the precast system in the construction of halls and buildings, and their inclusion in a unique structural engineering system.

The principle of complete reinforcement has been applied to lightweight concrete ceiling and roof beams. This principle enables an almost complete transfer of compressive, tensile and shear stresses onto the reinforcement. Hence, the lightweight concrete elements become a secondary supporting framework for local and global stabilization and take on the role of an anti-corrosive as well as protect against heat, noise and humidity.

Lightweight concrete elements have a low density which implies a reduction in the dead load and, hence, less reinforcement and improvement of insulation properties.

This precast system ensures quick, efficient and low cost assembly.

The system offers the possibility for the efficient completion of precast lightweight concrete elements and facade finishing.

Description of Drawings

The drawings present a new precast lightweight concrete system for the construction of halls and buildings (in further text referred to as - System). Each drawing shows one possible way to apply the system and does not limit the rights contained in the patent claims.

Drawing 1 shows a cross-section of a one-storey hall built by using this

System,

Drawing 2 shows a cross-section of a two-storey hall built by using this

System,

Drawing 3 shows the dimensions of the main roof beam,

Drawing 4 shows one-half of the reinforced framework of the roof beam,

Drawing 5 shows a cross-section through the center of the roof beam

Drawing 6 shows a cross-section of the main beam opening,

Drawing 7 shows the longitudinal dimensions of the slab,

Drawing 8 shows the peφendicular dimensions of the slab,

Drawing 9 shows a detail of the longitudinal reinforcement

Drawing 10 shows a detail of the perpendicular slab reinforcement

Drawing 11 shows a layout of the roof valley beam

Drawing 12 shows a cross-section and reinforcement of the valley beam Drawing 13 shows the axonometry of the external column with the foundation

Drawing 14 shows the axonometry of the internal column with the foundation.

Detailed Description of the Patent

The new precast lightweight housing construction system, as shown in Drawing 1 and 2, consists of the following elements: main roof beams (1 ), roof beams (2), roof valleys (3), roof-ceiling TT beams (4), facade panels (5), columns (6), foundation beams (7) and precast foundations (8).

Drawings 3, 4, 5 and 6 present a precast main roof beam (1 ). Its has a cross- sectional shape of T type and is made of lightweight concrete with a recommended density lower than 1500 kg/m3, compressive strength higher than 1.0 MPa, tensile strength higher than 0.1 MPa, shear strength higher than 0.05 MPa and initial modulus of elasticity 10000 MPa > E > 500 MPa. The length of the beam, its height in the middle and at the edges, the thickness of the rib (1.1 ), the thickness of the belt (1.2) are chosen taking into account the computation of mechanical resistance and stability. The recommended beam span (1 ) is 12-25 m, the recommended beam height at the center (1 ) is 1.0 - 2.5 m, the recommended slope of the upper surface is 1 :20 - 1 :4. The main roof beam (1) consists of the following elements: rib (1.1), belt (1.2), bearings (1.3), openings (1.4), either circular or other shapes, which are not obligatory, reinforcement of the lower zone (1.5), reinforcement of the upper zone (1.6) consisting of one or more bars, plates for the continuation of reinforcement (1.8), reinforcement of belts (1.9) and secondary reinforcement (1.10). The reinforcement of the upper zone (1.5) together with the reinforcement of the lower zone (1.6) and the filler reinforcement (1.7) form a V truss with non-parallel chords. The girder filling is placed in at least one plane. The reinforcement is connected by means of welded lap joints. The roof beam (2) consists of the same parts as the beam (1) but the slope of the upper edge is unilateral. The roof valley (3) is a precast lightweight concrete beam, presented in Drawings 10, 11 and 12. The roof valley is used for: (1 ) longitudinal connection of the column tops, (2) as the bearing for roof beams, (3) as support to facade panels, (4) as a drain for rainfall from the roof. The roof valley (3) is a lightweight concrete beam with the cross-sectional shape which is type U and is made of lightweight concrete with a recommended density lower than 1800 kg/rn3 compressive strength higher than 2.0 MPa, tensile strength higher than 0.5 MPa shear strength higher than 0.1 MPa and initial modulus of elasticity E >3000 MPa.

The beam section exposed to water action can be made of lightweight concrete with a higher density or of concrete with normal density. The roof valley consists of the following elements: slab (3.1), two ribs (3.2) bearings for the roof beams (3.3), sections above the columns (3.4) reinforcement of the lower zone (3.5) placed in the slab (3.1 ), reinforcement of the upper zone (3.6), ribs reinforcement (3.7) and secondary reinforcement of the slab (3.8). The length of the valley, the height and thickness of the ribs (3.2) the thickness and width of the slab (3.1 ) are chosen taking into account the computations of mechanical resistance and stability and the conditions of quick rainfall drainage. The recommended span of the valley (3) is 5 - 15 m, the recommended height of the beam in the middle (1 ) is 0.5 - 2.0.

The roof-ceiling TT slab (4) is a precast, completely reinforced lightweight concrete structure, presented in Drawings 7, 8 and 9 and is intended for the roof and ceiling structures. It is a lightweight concrete element with a TT type cross- section and is made of lightweight concrete with a recommended density lower than 1500 kg/m3, compressive strength higher than 1.0 MPa, tensile strength higher than 0.2 MPa, shear strength higher than 0.05 MP and the initial modulus of elasticity 10000 MPa > E > 500 MPa.

The roof-ceiling TT slab (4) consists of the following elements: joint (connecting) slab (4.1 ), two ribs (4.2), bearings (4.3), reinforcement of the lower ribs belt (4.4) consisting of one or more bars, reinforcement of the upper ribs flang (4.5} consisting of one or more bars, reinforcement filling of the rib (4.6) consisting of one or more bars, secondary ribs reinforcement and the connecting plate (4.7} The length of the TT slab (4), the height and thickness of the ribs (4.2), the thickness and width of the slab (4.1 ) are chosen according to the computations of mechanical resistance and stability. The recommended span of the TT slab

(4) ranges from 3-12 m and the recommended height of the support in the middle (1 ) is from 0.2 - 0.8 m.

The reinforcement of the upper ribs zone (4.5) and the lower ribs zone (4.4) with the reinforcement of the rib filling (4.6) form a V truss with parallel chords. The filling of the rib grid is placed in at least one plane. The reinforcement is welded and uninterrupted by means of lap joints .

The facade panel (5) is a precast lightweight concrete slab structure presented in Drawings 1 and 2, intended for building walls and facades. It is made of lightweight concrete with a recommended density lower than 1200 kg/m3 and a compressive strength higher than 1.0 MPa. The length, height and thickness of the facade panel (5) are chosen by taking into account the geometry of the halls. mechanical resistance, stability and physical conditions of the buildings. The wall panel can be multi-layered if a slab of expanded polystyrene is inserted in the middle of the cross-section.

Washed concrete, plates or external grout are placed on the external side of the panel.

The hall columns (6) are supporting structures presented in Drawings 1 , 2, 13 and 14. They are conventional reinforced concrete elements which complete the structure.

The foundation beams (7) are bearing structures for the wall panels presented in

Drawings 1 and 2. They are conventional reinforced concrete elements which complete the structure.

The precast foundations (8) are sections of the foundations on which columns are placed, as presented in Drawings 1 , 2, 13 and 14. They are conventional reinforced concrete elements which complete the structure.

One of the possible techniques for the hall construction includes the following phases. First, the foundations, either precast or monolithic, are placed in the previously determined places. Subsequently, these foundations are fastened by foundation beams (7), which are either precast or monolithic. Then, the columns (6), either precast or monolithic, are placed into the foundations. After this, the roof valleys (3) are placed along the hall or a building. If this hall or building has two or more storeys then perpendicular (transversal) roof beams are placed and then the roof TT slabs (4) are placed inside them. Subsequently, roof beams (1 ) and (2) are placed. Finally, the roof TT slabs (4) are placed followed by the facade panels (5) which are fixed to the foundation beams (7) and roof valley. (3).

One of the possible techniques for the construction of a lightweight concrete structure is lightweight concrete based on expanded polystyrene (styroconcrete) If the lightweight concrete structure is based on light styroconcrete then the density of lightweight concrete has to be higher than 800 kg/m3 when it is exposed to any type of fire loading.

Industrial application

The application of this patent in industry is evident. The system is applicable in practice to new methods of halls and buildings construction which is based on precast lightweight concrete elements.

Claims

PATENT CLAIMS

1.) Precast lightweight concrete system for halls and housing construction as presented in Drawings 1 and 2, is characterized by the following elements: main roof beam (1 ), roof beam (2), roof valley (3), roof-ceiling beam (4), facade panels (5), columns (6), foundation beams (7) and foundations (8); all these elements, by their forms and dimensions, form a compatible system.

2.) Precast lightweight roof beams (1) and (2), according to Claim 1 , with the length, height and rib thickness, flang thickness and upper edge slope chosen according to the bearing capacity computation, stability and roof geometry, is characterized by the fact that it has a T type form and is made of lightweight concrete with a density lower than 1500 kg/m3, compressive strength higher than 0.1 MPa, tensile strength higher than 0.2 MPa, shear strength higher than 0.05 MPa and initial modulus of elasticity of 10000 MPa > E > 500 MPa.

3.) Precast lightweight roof beams (1 ) and (2) according to patent claims 1-2, is characterized by the following elements: rib (1.1 ), belt (1.2), bearings (1.3), openings (1.4), either circular or of other different shapes, which are not obligatory, reinforcement of the lower zone (1.5), reinforcement of the upper zone (1.6) consisting of one or more bars, reinforcement of the filling (1.7) consisting of one or several bars, slabs for the continuation of the reinforcement (1.8), reinforcement of the flangs (1.9) and secondary reinforcement (1.10).

4.) Precast lightweight roof beams (1 ) and (2), according to patent clams 1-3, whose reinforcement is joined by welding and, thus, uninterrupted, and, if necessary, coated with anti-corrosive agents, is characterized by the fact that the reinforcement of the lower zone (1.5) together with the upper zone (1.6) and the reinforcement of the filling (1.7) form a V truss with non-parallel chords, where the filling is placed into at least one plane and where the local stability of the compressive bars is , if necessary, ensured by the joints (1.9) which are not obligatory. 5.) Roof valley, according to patent claim 1 , characterized by the cross-sectional shape which of type U, is made of lightweight concrete with a density lower than 1800 kg/m3, compressive strength higher than 2.0 MPa, tensile strength higher than 0.

5 MPa, shear strength higher than 0.1 MPa and initial modulus of elasticity E > 3000 MPa, where beam sections exposed to water action can be made of lightweight concrete with a higher density or of concrete with a normal density, which is not obligatory.

6.) Roof valley (3) according to patent clams 1 and 5, whose length as well as height and thickness of ribs and the thickness of the slabs are chosen according to the computations of bearing capacity and stability and rainfall; its reinforcement is welded and uninterrupted; if necessary, it is coated with anti-corrosive agents and is characterized by the following component elements: slab (3.1), two ribs (3.2), bearing for the roof beams (3.3), continuation above the beams (3.4), reinforcement of the lower zone (3.5) placed into the slab (3.1), reinforcement of the upper zone (3.6), ribs reinforcement (3.7) and the secondary reinforcement of the slabs (3.8).

7.) Roof-ceiling TT lightweight concrete slab (4) according to patent claim 1 , whose length, height and thickness of the ribs, thickness of the connecting slab are chosen according to the computations of the bearing capacity and stability, characterized by the fact that the cross-section is a TT type, made of lightweight concrete with a density lower than 1500 kg/m3, compressive strength higher than 0.1 MPa, tensile strength higher than 0.2 MP, shear strength higher than 0.05 MPa and initial modulus of elasticity 10000 MPa E > 500 MPa.

8.) Roof-ceiling TT lightweight concrete slab (4) according to patent claims 1 and 7, is characterized by the following component elements: joint slab (4.1 ), two ribs (4.4) consisting of one or several bars, reinforcement of the upper rib chord (4.5) made of one or more bars, reinforcement of the rib filling (4.6) consisting of one or several bars, secondary rib reinforcement (4.7) and the connecting slab.

9.) Roof-ceiling TT lightweight slab (4) according to patent claims 1 , 7 and 8, is characterized by the fact that the reinforcement of the upper rib zone (4.5) and the lower rib zone (4.4) together with the reinforcement of the rib filling (4.6) form a V truss with parallel chords, where the filling of the rib grid (4.6) is placed into at least one plane.

10.) Facade lightweight concrete panel (5), according to patent claim 1 , whose length, height and thickness are chosen in accordance with the computations of the bearing capacity, stability and physical conditions of the building, whose reinforcement is welded and, if necessary, coated with anti- corrosive agents, is characterized by the fact that it is made of lightweight concrete with a recommended density lower than 1200 kg/m3 and compressive strength higher than 1.0 MP; wherein the panel may be multi- layered, so that a slab of expanded polystyrene is inserted in the middle of the cross-section, which is not obligatory; on the external side of the panel the facade may be finished in the form of washed concrete, plates or external mortar which is not obligatory either.