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Title:
WOODEN STRUCTURE SUITABLE AS A LIVING OR OFFICE AREA AND METHOD FOR THE PRODUCTION AND PLACEMENT THEREOF
Document Type and Number:
WIPO Patent Application WO/2018/163113
Kind Code:
A1
Abstract:
According to an embodiment, the invention comprises a wooden structure (910) suitable as a living or office area, comprising a floor and a ceiling profile connected via a set of upright beams (200-201), wherein corner joints of the floor and ceiling profile comprise two dowel joints (501-502) and a blind mortise and tenon joint (500) combined with two other dowel joints (503-504), wherein the joints between the set of upright beams (200-201) and the floor and ceiling profiles comprise two dowel joints (401-402) and a blind mortise and tenon joint (400), and wherein side beams (120-121) in the floor and ceiling profiles are connected to side beams (110-113) by dovetail joints (600).

Inventors:
MIKOVCAK MARTIN (SK)
DE BACKER MICHIEL (BE)
Application Number:
PCT/IB2018/051542
Publication Date:
September 13, 2018
Filing Date:
March 09, 2018
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ARK SHELTER BVBA (BE)
International Classes:
E04B1/26; E04H1/12
Foreign References:
JPH10219818A1998-08-18
DE1759961A11971-07-15
US1423949A1922-07-25
DE9211330U11993-02-18
Other References:
None
Attorney, Agent or Firm:
IP HILLS NV (BE)
Download PDF:
Claims:
CLAIMS

1 . A substantially wooden structure suitable as a living and/or an office area, comprising:

- a bottom profile, the floor profile, comprising bottom side beams (1 10- 1 12) and bottom transverse beams (120-121 ),

o wherein each bottom side beam (1 10-1 12) is connected to another bottom side beam (1 10-1 12) by means of a corner joint, thus forming a first rectangular frame; and o wherein the bottom transverse beams (120-121 ) are distributed evenly and placed within the first rectangular frame perpendicular to the longitudinal direction thereof, each bottom side beam being connected in each case to a bottom transverse beam via two opposite sides;

- a set of upright beams (200-201 ) arranged perpendicularly to the floor profile at the outer side thereof and connected thereto, thus forming four walls; and

- a top profile, the ceiling profile, comprising top side beams (300-303) and top transverse beams (310-31 1 ),

o wherein each top side beam (300-303) is connected to

another top side beam (300-303) by means of a corner joint, thus forming a second rectangular frame, the rectangular frame being placed on the set of upright beams (200-201 ) and connected thereto; and

o wherein the top transverse beams (310-31 1 ) are distributed evenly and placed within the second rectangular frame perpendicular to the longitudinal direction thereof, each top side beam (310-31 1 ) being connected in each case to a top transverse beam (300-303) via two opposite sides;

CHARACTERIZED IN THAT

- each corner joint comprises two dowel joints (501 -502) and a blind mortise and tenon joint (500) in the transverse direction of the respective rectangular frame and two dowel joints (503-504) in the longitudinal direction of the respective rectangular frame;

- each joint between the respective transverse beams and respective side beams comprises a dovetail joint (600); and

- each joint between an upright beam and the floor profile and ceiling profile, respectively, comprises two dowel joints (401 -402) and a blind mortise and tenon joint (400).

2. Structure according to Claim 1 , wherein the distance between the evenly distributed bottom and top transverse beams (120-121 , 310-31 1 ), respectively, is in a range from 65 cm to 75 cm, preferably 70 cm.

3. Structure according to one of the preceding claims, wherein the distance between the upright beams (200-201 ) is in a range from 65 cm to 75 cm, preferably 70 cm.

4. Structure according to any of the preceding claims, the floor profile further comprising one or more trimmer joists (131 ) and/or one or more trimmed joists (130), the trimmer joists (131 ) and/or trimmed joists (130) being positioned such that they form one or more openings, each opening being suitable for connecting a utility of the living and/or office area.

5. Structure according to any of the preceding claims, the ceiling profile further comprising one or more trimmer joists and/or one or more trimmed joists, the trimmer joists and/or trimmed joists being positioned such that they form one or more openings, an opening being suitable as a discharge channel of a heating element and/or ventilation system.

6. Structure according to any of the preceding claims, the structure further comprising:

- one or more openings in a wall formed by the set of upright beams, each opening being reinforced at the outer edge by means of reinforcing beams;

- a casing in each one or more openings suitable for a door and/or a window; CHARACTERIZED IN THAT

the structure further comprises:

- a shutter pivotably attached to a sill of a casing, wherein:

o in the closed position, the shutter fully seals the opening of the casing (700); and

o in the open position, the shutter is suitable as a terrace for the living and/or office area (800).

7. Structure according to claim 6, wherein, in the open position, the upper surface of the shutter is situated in the same plane as the upper surface of the floor profile.

8. Structure according to any of the preceding claims, further comprising four metal hooks stably fastened to the top of the ceiling profile at the outer side of the second rectangular profile and positioned rotationally symmetrically with respect to the centre thereof, the metal hooks being suitable for fastening a hoisting belt or hoisting chain for hoisting the structure. 9. Structure according to claim 8, further comprising four band or cable guides stably fastened to the bottom of the floor profile at the outer side of the first rectangular profile and positioned rotationally symmetrically with respect to the centre thereof, wherein a band or cable guide is further positioned in such a way that a band or cable, tensioned between a metal hook and a band or cable guide, runs parallel to an upright beam.

10. Method for erecting the structure according to claim 8 or 9 on a predetermined site, the method comprising:

- placing at least four prefabricated concrete blocks, each on a layer of stabilized sand, on the site;

- positioning feed and/or supply pipes of the utilities for the living and/or office area on the site;

- lowering the structure, wherein: o the structure is hoisted with the aid of two hoisting belts or hoisting chains, a hoisting belt or hoisting chain being fastened to two opposite metal hooks;

o the two hoisting belts or hoisting chains are separated by a spreader at the top of the structure; and

o the bottom of the floor profile is situated in a range from

10 cm to 15 cm above the top of the plane formed by the tops of the concrete blocks;

- connecting the utilities;

- further lowering the structure in such a way that the structure rests stably on the concrete blocks.

1 1 . Method for erecting the structure on a predetermined site according to claim 10, wherein:

- the structure is hoisted with the aid of two hoisting belts or hoisting chains, a hoisting belt or hoisting chain being fastened to two opposite metal hooks and further guided via the band or cable guides;

- connecting the utilities;

- further lowering the structure in such a way that the structure rests stably on the concrete blocks;

CHARACTERIZED IN THAT

the concrete blocks are positioned in such a way that the hoisting belts or hoisting chains can be removed once the structure rests on said concrete blocks.

12. Method for erecting the structure on a predetermined site according to claim 10 or 1 1 , wherein the concrete blocks are dimensioned in such a way that the bottom of the structure is situated in a range from 10 cm to 15 cm above the ground level of the site.

13. Method for manufacturing the structure according to claim 1 , the method comprising:

- manufacturing the floor profile upside down; - applying a moisture-resistant protective layer to the bottom of the floor profile;

- inverting the floor profile;

- placing the set of transverse beams on the floor profile;

- placing the ceiling profile on the set of transverse beams; and

- applying an ethylene propylene diene monomer film to the top of the ceiling profile.

Description:
WOODEN STRUCTURE SUITABLE AS A LIVING OR OFFICE AREA AND METHOD FOR THE PRODUCTION AND PLACEMENT THEREOF

Technical Field

[01] The invention relates to a movable structure suitable as a living or office area and a method for the production and placement thereof.

Prior Art

[02] Movable structures suitable as a living or office area are known. There are structures which can and may be transported by road, such as a caravan, for example, or which are integrated into a motor vehicle, such as a camper van, for example. However, since these structures may be transported behind a car or are integrated into a vehicle, they are rather limited in terms of dimensions and thus space. These limitations are imposed, inter alia, by the traffic regulations and/or a car's maximum permitted towing capacity.

[03] Other movable structures which are suitable as a living or office area are mobile homes which are delivered to their plot by a transport company and remain on the same site for a relatively long period. Mobile homes have more space compared to caravans or camper vans. This increases the comfort of a user of such a living or office area.

[04] As mobile homes must be able to withstand changing weather conditions, such as rain, strong wind and/or freezing temperatures, they are usually constructed from an aluminium framework. As a result, the mobile home also has sufficient strength to enable it to be transported and thus to reduce the risk of deformation. The outer walls may comprise various materials, such as aluminium sheets or fibreglass-reinforced plastic, for example. An insulating layer is also applied, comprising, for example, of expanded polystyrene or polyurethane and placed between the outer walls and the inner walls. In that case, the inner walls may then consist of wood. [05] However, it is a drawback that aluminium or fibreglass-reinforced plastic is used as outer wall for a mobile home, since these materials have a high vapour diffusion resistance. As a result, insufficient water vapour may be discharged in the living or office area, which not only has a disadvantageous effect on the comfort of the inhabitants, such as odour nuisance, for example, but may also cause potential damage, such as damp problems, for example.

[06] As a result, there is a need for a movable structure suitable as a living or office area which is sufficiently strong to enable it to be moved and to withstand changing weather conditions and also has a low vapour diffusion resistance.

Summary of the Invention

[07] It is an object of the present invention to provide a movable structure suitable as a living or office area and a method for the production and placement thereof, which structure has a low vapour diffusion resistance and at the same time is sufficiently strong to enable it to be moved and also to withstand changing weather conditions.

[08] This object is achieved, according to a first aspect of the invention, by providing a substantially wooden structure suitable as a living and/or an office area, comprising a bottom profile, the floor profile, comprising bottom side beams and bottom transverse beams, wherein each bottom side beam is connected to another bottom side beam by means of a corner joint, thus forming a first rectangular frame; and wherein the bottom transverse beams are distributed evenly and placed within the first rectangular frame perpendicular to the longitudinal direction thereof, each bottom side beam being connected in each case to a bottom transverse beam via two opposite sides; a set of upright beams arranged perpendicularly to the floor profile at the outer side thereof and connected thereto, thus forming four walls; and a top profile, the ceiling profile, comprising top side beams and top transverse beams, wherein each top side beam is connected to another top side beam by means of a corner joint, thus forming a second rectangular frame, the rectangular frame being placed on the set of upright beams and connected thereto; and wherein the top transverse beams are distributed evenly and placed within the second rectangular frame perpendicular to the longitudinal direction thereof, each top side beam being connected in each case to a top transverse beam via two opposite sides, characterized in that each corner joint comprises two dowel joints and a blind mortise and tenon joint in the transverse direction of the respective rectangular frame and two dowel joints in the longitudinal direction of the respective rectangular frame; each joint between the respective transverse beams and respective side beams comprises a dovetail joint; and each joint between an upright beam and the floor profile and ceiling profile, respectively, comprises two dowel joints and a blind mortise and tenon joint.

[09] Instead of providing an aluminium framework, the framework is fully constructed using wooden beams, both for the floor and for the ceiling profile. Furthermore, all walls are also constructed from wooden beams which are stably connected to both profiles. As a result, the framework has sufficient strength, on the one hand, to resist changing weather conditions and, on the other hand, also when the structure is transported.

[10] The joints between the different profiles and beams are configured by way of wooden joints. The corner joints comprise two dowel joints and a blind mortise and tenon joint in the transverse direction of each rectangular frame of the floor and ceiling profiles and two dowel joints in the longitudinal direction of each rectangular frame. The joints between the transverse beams and side beams comprise dovetail joints, and two dowel joints and a blind mortise and tenon joint are made between an upright beam and the floor and ceiling profile. By placing the joints in such a way, it is possible to absorb dilatations caused by temperature differences. These dilatations may be followed by compressions, which can be absorbed in the same way. If the structure is thus deformed by temperature differences, this will occur equally in each direction, since the same material is used for the entire framework, thus limiting damage and/or lasting deformation resulting from this. [11] In other words, it is an advantage that the same material is used both to construct the structure and for the joints between its parts. This is because a uniform expansion coefficient over the entire structure ensures that tension which builds up internally between the elements is reduced to a minimum.

[12] The floor and ceiling profiles, together with the transverse beams which connect both profiles, then form the framework of the wooden structure. Wooden panels can then be arranged on each plane of this framework in order to fully enclose the structure. In predetermined places, the necessary space can be left open to provide one or more doors for access and one or more windows for light. In this way, the structure is then suitable as a living and/or office area.

[13] Using wood for the construction of the structure further has the advantage that water vapour can be discharged in an optimum manner due to the low vapour diffusion resistance of this material. As a result, potential damage owing to the build-up of moisture is avoided.

[14] According to an embodiment of the invention, the distance between the evenly distributed bottom and top transverse beams, respectively, is in a range from 65 cm to 75 cm, preferably 70 cm. [15] Both in the floor and ceiling profile, the transverse beams are evenly distributed with the distance between one another in the range from 65 cm to 75 cm, with 70 cm being preferred. As a result, there is a good balance between, on the one hand, sufficient strength of the profiles and, on the other hand, weight saving owing to the space left open between the beams.

[16] By constructing both profiles in an identical manner, a further advantage is that they will deform in the same way in the event of changing temperatures.

[17] According to an embodiment of the invention, the distance between the upright beams is in a range from 65 cm to 75 cm, preferably 70 cm.

[18] The upright beams, which form the framework of the side walls of the structure, are placed at the same distance as the transverse beams in the floor and ceiling profiles. This results in a uniform construction of the entire structure. In addition, there are also the same advantages as apply to the floor and ceiling profiles. [19] According to an embodiment of the invention, the floor profile further comprises one or more trimmer joists and/or one or more trimmed joists, the trimmer joists and/or trimmed joists being positioned such that they form one or more openings, each opening being suitable for connecting a utility of the living and/or office area.

[20] In the floor profile, the necessary openings are provided in order to connect utilities, such as a water supply line and/or drain pipe, for example, but also possibly energy cables. These openings are formed by using trimmer joists and trimmed joists. This retains the strength of the floor profile.

[21] According to an embodiment of the invention, the ceiling profile further comprises one or more trimmer joists and/or one or more trimmed joists, the trimmer joists and/or trimmed joists being positioned such that they form one or more openings, an opening being suitable as a discharge channel of a heating element and/or ventilation system. [22] On the top of the wooden structure in the ceiling profile, openings are provided for installing discharge channels of a heating element, such as a stove, for example, and additionally or separately of a ventilation system. A discharge channel of a ventilation system, for example, is installed in an area where a higher concentration of water vapour is expected than in other areas of the structure. This may be, for example, an area in which a shower cubicle is arranged. As a result, water vapour which is present can be discharged faster than the natural discharge of water vapour, which is determined by the vapour diffusion resistance of the materials used. [23] According to an embodiment of the invention, the structure further comprises one or more openings in a wall formed by the set of upright beams, each opening being reinforced at the outer edge by means of reinforcing beams; a casing in each one or more openings suitable for a door and/or a window, characterized in that the structure further comprises a shutter pivotably attached to a sill of a casing, wherein, in the closed position, the shutter fully seals the opening of the casing; and, in the open position, the shutter is suitable as a terrace for the living and/or office area.

[24] In one or more walls, larger openings than these may also be provided, determined by the distances between the upright beams in the range of 65 cm to 75 cm. These openings are then reinforced by means of reinforcing beams in order to thus retain the strength of the structure. Furthermore, a casing is provided in an opening, which casing comprises a left-hand and a right-hand jamb and a sill and a lintel. Windows may be inserted here, for example, in order to have sufficient light, but also to have a larger access in order, for example, to be able to move furniture which is wider than the range of 65 cm to 75 cm into the structure. [25] In a casing, a shutter is then pivotably attached to the sill. In the closed position, the shutter then fully seals the opening of the casing, while, in the open position, it is suitable as a terrace for the living and/or office area.

[26] In the closed position, the shutter then not only ensures sufficient strength, but is also suitable as a deterrent against, for example, theft. Furthermore, it also serves as a sunblind. [27] In the open position, thus when the shutter is lowered, it is used as a terrace. As a result, there is no need to provide a separate terrace on the site wherein the structure is situated.

[28] According to an embodiment of the invention, in the open position, the upper surface of the shutter is situated in the same plane as the upper surface of the floor profile.

[29] As a result, there is no height difference between both surfaces when the shutter is used as a terrace. This means that there is no step and dangerous situations which may be caused, for example, by tripping are thus avoided. Furthermore, equipment such as furniture can also be moved in an efficient manner from inside the structure to outside, and vice versa.

[30] According to an embodiment of the invention, the structure further comprises four metal hooks stably fastened to the top of the ceiling profile at the outer side of the second rectangular profile and positioned rotationally symmetrically with respect to the centre thereof, the metal hooks being suitable for fastening a hoisting belt or hoisting chain for hoisting the structure.

[31] By stably fastening the four metal hooks to the top of the structure, it can always be hoisted without having to mount the hooks in advance. On account of the rotationally symmetrical positioning with respect to the centre, the structure can also be hoisted with the plane of the floor profile remaining parallel to the plane of the ground from which the structure is hoisted. As a result, the structure can be moved in a safe manner from a loading platform to a site or from the site to the loading platform again.

[32] The rotationally symmetrical placement also ensures that forces in the different hoisting belts or hoisting chain are uniformly distributed. This reduces the risk of a hoisting belt or a hoisting chain breaking or tearing. [33] According to an embodiment of the invention, the structure further comprises four band or cable guides stably fastened to the bottom of the floor profile at the outer side of the first rectangular profile and positioned rotationally symmetrically with respect to the centre thereof, wherein a band or cable guide is further positioned in such a way that a band or cable, tensioned between a metal hook and a band or cable guide, runs parallel to an upright beam.

[34] According to an embodiment, band or cable guides are also attached to the bottom. A hoisting belt or hoisting chain is then fastened to one of the four metal hooks on the top and subsequently drawn around the structure along the bottom via a band or cable guide and once again fastened to an opposite metal hook. As a result, two hoisting belts or hoisting chains may be used to lift the structure in order to move it. Hoisting the structure in this way prevents the structure from beginning to swing. The band or cable guides also ensure not only that the hoisting belts or hoisting chains are kept in the same position, but also that the walls of the wooden structure are not damaged.

[35] According to a second aspect of the invention, a method is provided for erecting the structure according to one of the preceding embodiments on a predetermined site, the method comprising placing at least four prefabricated concrete blocks, each on a layer of stabilized sand, on the site; positioning feed and/or supply pipes of the utilities for the living and/or office area on the site; lowering the structure, wherein the structure is hoisted with the aid of two hoisting belts or hoisting chains, a hoisting belt or hoisting chain being fastened to two opposite metal hooks and possibly guided via the band or cable guides; the two hoisting belts or hoisting chains are separated by a spreader at the top of the structure; and the bottom of the floor profile is situated in a range from 10 cm to 15 cm above the top of the plane formed by the tops of the concrete blocks; connecting the utilities; further lowering the structure in such a way that the structure rests stably on the concrete blocks; and wherein the concrete blocks are positioned in such a way that the hoisting belts or hoisting chains can be removed once the structure rests on said concrete blocks; and are dimensioned in such a way that the bottom of the structure is situated in a range from 10 cm to 15 cm above the ground level of the site. [36] In order to place the structure on a predetermined site, at least four prefabricated concrete blocks must be placed on a layer of stabilized sand. The advantage is that only each block separately needs a layer of stabilized sand and that it is not necessary to provide a layer over the entire surface on which the structure is placed. Before the structure is placed on the blocks, the feed and/or supply pipes of the utilities are positioned in such a way that they can be connected. The structure is hoisted with the aid of hoisting belts or hoisting chains, each fastened to the metal hooks. These hoisting belts or hoisting chains are separated by a spreader at the top of the structure. The structure is then lowered until it is situated in a range from 10 cm to 15 cm above the top of the plane formed by the tops of the concrete blocks. The pipes of the utilities are then connected. The final step is then to completely lower the structure so that it rests stably on the concrete blocks. [37] The advantage is that the structure can thus be placed quickly on a predetermined site as it does not need to be placed on full foundations. [38] According to an embodiment, the structure can also be hoisted with the aid of two hoisting belts or hoisting chains, a hoisting belt or hoisting chain being fastened to two opposite metal hooks and further guided via the band or cable guides; connecting the utilities; further lowering the structure in such a way that the structure rests stably on the concrete blocks, characterized in that the concrete blocks are positioned in such a way that the hoisting belts or hoisting chains can be removed once the structure rests on said concrete blocks. [39] Also hoisting the structure via the bottom with the aid of the band or cable guides prevents the structure from beginning to swing when it is hoisted. The metal hooks and band or cable guides in combination with the concrete blocks are then positioned and placed in such a way that the hoisting belts or hoisting chains can be removed when the structure rests stably on the concrete blocks.

[40] According to a third aspect of the invention, a method is provided for manufacturing the structure according to the first aspect of the invention, the method comprising manufacturing the floor profile upside down; applying a moisture-resistant protective layer to the bottom of the floor profile; inverting the floor profile; placing the set of transverse beams on the floor profile; placing the ceiling profile on the set of transverse beams; and applying an ethylene propylene diene monomer film to the top of the ceiling profile.

[41] In other words, the structure is constructed by first manufacturing the floor profile. This is built first with the bottom of the floor profile facing upwards such that a protective layer can be applied to it. The floor profile is then turned in order to subsequently attach the set of transverse beams thereto and further the ceiling profile on top of them. An ethylene propylene diene monomer film is then applied to the ceiling profile such that resistance against extreme weather conditions is ensured. Brief Description of the Drawings

[42] The invention will now be described further with reference to the drawings, in which:

Fig. 1 diagrammatically shows an embodiment of a floor profile of the structure; and Fig. 2 diagrammatically shows an embodiment of a floor profile and a set of upright beams; and

Fig. 3 diagrammatically shows an embodiment of a floor profile, a set of upright beams and a ceiling profile; and

Fig. 4 diagrammatically shows two dowel joints and a blind mortise and tenon joint; and

Fig. 5 diagrammatically shows a corner joint; and

Fig. 6 diagrammatically shows a dovetail joint; and

Fig. 7 diagrammatically shows an embodiment of a shutter in the closed position; and

Fig. 8 diagrammatically shows an embodiment of a shutter in the open position; and

Fig. 9 diagrammatically shows an embodiment of the positioning of concrete blocks. Description of Embodiments

[43] Fig. 1 diagrammatically shows an embodiment of a floor profile of the wooden structure. The floor profile comprises four bottom side beams 1 10 to 1 12, which form the first rectangular frame. Transverse beams are then placed into this rectangular frame, such as transverse beams 120 and 121 , for example. According to an embodiment, trimmed joists and trimmer joists may also be inserted, such as trimmer joist 131 and trimmed joist 130, for example.

[44] A set of upright beams is then placed onto the floor profile perpendicularly thereto. Fig. 2 diagrammatically depicts a set of upright beams perpendicularly arranged on the floor profile. The set of upright beams is then placed onto the outer side of the floor profile, such as upright beams 200 and 201 , for example.

[45] A ceiling profile is then placed on top of the set of upright beams, then forming a complete framework of the wooden structure. Fig. 3 diagrammatically depicts such a framework according to an embodiment of the invention. The ceiling profile comprises side beams 300 to 302, in this case forming a second rectangular frame. Transverse beams are then distributed evenly in this second rectangular frame, in the same way as in the floor profile, such as transverse beams 310 and 31 1 , for example.

[46] The joint between the floor profile and an upright beam, such as upright beam 200 with transverse beam 1 12, for example, comprises two dowel joints and a blind mortise and tenon joint. Fig. 4 diagrammatically depicts such a joint. The blind mortise and tenon joint 400 is then combined with two dowel joints 401 and 402.

[47] Fig. 5 diagrammatically depicts a corner joint between side beams which are connected to one another, such as side beams 1 10 to 1 13 for the floor profile and side beams 300 to 303 for the ceiling profile, respectively. A corner joint for the transverse direction of a rectangular frame comprises two dowel joints 501 and 502 and a blind mortise and tenon joint 500 and of two dowel joints 503 and 504 for the longitudinal direction of a rectangular frame.

[48] The joints of the upright beams, such as upright beams 200 and 201 , with the floor profile at the bottom and the ceiling profile at the top comprise dovetail joints. Fig. 6 diagrammatically depicts such a dovetail joint 600.

[49] According to an embodiment of the invention, one or more casings are also provided in which a shutter is pivotably arranged. Fig. 7 diagrammatically depicts such a shutter 700 in the closed position. The shutter 700 then seals the casing. In the open position, the shutter can be used as a terrace. Fig. 8 diagrammatically depicts such a terrace 800.

[50] The structure can be placed on a predetermined site. Four or more concrete blocks are then placed on this site. Fig. 9 diagrammatically depicts a structure 910 with concrete blocks positioned with respect to the structure 910. In order to be able to place the structure 910, at least four concrete blocks are needed, such as concrete blocks 900 to 903, for example. Before the concrete blocks are placed, a layer of stabilized sand is laid on each location where a concrete block is placed.