Prefabricated concrete element for the construction of a retaining wall

Abstract

The present invention relates to a precast concrete element for the construction of a retaining wall comprising a wall section (1), a foot (2), and a reinforcing mesh, wherein the precast concrete element has an L-shaped cross-section, wherein a first leg is the foot (2) and a second leg is the wall section (1), wherein the first and second legs are substantially perpendicular to each other, and wherein the width in the direction of the first leg, the height in the direction of the second leg, and the length perpendicular to the L-shaped cross-section are defined, wherein the foot (2) is at least 1 cm shorter than the wall section (1) at both ends in the longitudinal direction. Fig. 1

Description

Title of the invention: Prefabricated concrete element for the construction of a retaining wall

[0001] The invention relates to a prefabricated concrete element for the construction of a retaining wall.

[0002] Retaining walls are a well-known construction in architecture. Retaining walls are designed to compensate for the staggered unevenness of a piece of land. The purpose of the retaining wall is to retain higher ground or, in some cases, water, so that lower ground can be used without the risk of landslides or flooding.

[0003] Originally, retaining walls were built on site or were made of concrete cast in place. In many cases, however, it is possible to construct a retaining wall using precast concrete elements. Precast concrete elements can be manufactured in a factory under controlled conditions and assembled into a retaining wall on site. This is a more efficient and faster method of constructing retaining walls because standard precast concrete elements are used and the pouring of the precast concrete elements is not dependent on weather conditions.

[0004] A precast concrete element according to the state of the art is generally an L-shaped element. Known precast concrete elements have a number of disadvantages. First of all, the dimensions of precast concrete elements according to the state of the art are not always precise enough to ensure a precise fit of the precast concrete elements. This creates a narrow gap between adjacent precast concrete elements through which the earth passes. Over time, this can lead to subsidence of the ground.

[0005] A precast concrete element according to the prior art generally comprises a simple reinforcement. The reinforcement consists of a simple reinforcement mesh bent into an L shape. In the angle formed by the two legs of the L shape, the reinforcement mesh cannot absorb sufficient stresses in the concrete, which leads to the failure of the outer corner of the precast concrete element. The retaining wall weakens further and threatens to break.

[0006] The present invention aims at least to provide a solution for some of the above-mentioned problems.

[0007] To this end, the invention provides a prefabricated concrete element for the construction of a retaining wall comprising a wall section, a foot and a reinforcing mesh, wherein the prefabricated concrete element has a cross-section in L-shaped, wherein a first leg is the foot and a second leg is the wall section, wherein the first and second legs are substantially perpendicular to each other and wherein the width in the direction of the first leg, the height in the direction of the second leg and the length perpendicular to the L-shaped cross-section are defined, characterized in that the foot is at least 1 cm shorter than the wall section at both ends in the longitudinal direction.

[0008] The great advantage of a precast concrete element according to the present invention is that it comprises a foot and a wall section, the foot being at least 1 cm shorter than the wall section at both ends. Even when the dimensions of the precast concrete element are not entirely exact, it is possible to construct a retaining wall in which the wall sections of the precast concrete elements fit precisely. It does not create a gap through which earth can pass, and which can cause the ground fill to settle over time.

[0009] In a specific embodiment, the wall section comprises a heightwise groove in a first sidewall and a tooth on a longitudinally opposite second sidewall, wherein the groove and tooth are complementary.

[0010] According to one embodiment, the wall section comprises a groove in a first side wall and a tooth on an opposite second side wall, the tooth and the groove being complementary. This is advantageous because when the precast concrete elements according to the present invention are placed next to each other, the tooth of a first precast concrete element engages in the groove of a second precast concrete element, so that at the connection between two precast concrete elements, a solid multiple barrier for the soil is obtained in a direction transverse to the retaining wall.

[0011] [Fig. 1] shows a perspective view of a precast concrete element according to one embodiment of the present invention.

[0012] [Fig.2] shows a sectional view of a precast concrete element according to an embodiment of the present invention.

[0013] [Fig. 3] shows a perspective view of a precast concrete element according to an alternative embodiment of the present invention.

[0014] Unless otherwise stated, all terms used in the description of the invention, including technical and scientific terms, are used in the sense as generally understood by those skilled in the technical field of the invention. For a better judgment of the description of the invention, the following terms are explicitly explained.

[0015] Quoting numerical intervals by means of endpoints includes all integers, fractions and / or real numbers between endpoints, including those endpoints.

[0016] In the context of this document, the top load is the load applied to higher ground which is retained by a retaining wall. For example, a top load of more than 25 kN / m2 or heavy traffic according to EN 1991-1:LM1 with a clearance of 1 m from the edges is considered a high top load.

[0017] In a first aspect, the invention relates to a prefabricated concrete element for the construction of a retaining wall.

[0018] According to a preferred embodiment, the precast concrete element comprises a wall section, a foot and a reinforcing mesh. The precast concrete element has an L-shaped section, in which a first leg is the foot and a second leg is the wall section. The first leg and the second leg are substantially perpendicular to each other. In this text, the width extends in the direction of the first leg, the height in the direction of the second leg and the length in a direction perpendicular to the L-shaped section.

[0019] An L-shaped section is advantageous for the construction of a retaining wall, where the wall section retains higher ground and the footing is positioned below the higher ground. The moment that the higher ground exerts on the precast concrete element is offset by the weight of the higher ground on the footing, so that the retaining wall does not tip over.

[0020] The foot and the wall section have a first and a second end in the longitudinal direction. The foot is at least 1 cm shorter than the wall section at both ends. This means that both ends of the foot lie within the length of the wall section. Preferably, the foot is at least 1.5 cm shorter in the longitudinal direction at both ends, more preferably at least 2 cm, and even more preferably at least 2.5 cm. A dimension of a precast concrete element has an accuracy of ± 0.5 cm. Since the foot is at least 1 cm shorter than the wall section at both ends in the longitudinal direction, precast concrete elements whose dimensions are not entirely accurate, for example the length of the wall sections is 0.5 cm too short, fit precisely.This allows a retaining wall to still be built without there being a gap between adjacent precast concrete wall sections through which earth can pass, causing the ground to settle over time.

[0021] Even when the dimensions of the precast concrete element are not entirely exact, it is possible to construct a retaining wall in which the wall sections of the precast concrete elements fit precisely. It does not create a gap through which earth can pass, which can lead to subsidence of the ground over time. A precast concrete element according to the present invention is advantageous for the construction of robust retaining walls.

[0022] According to one embodiment, the wall section comprises a groove in the height direction in a first side wall and a tooth on an opposite side wall in the longitudinal direction. The tooth and the groove are complementary. The first and second side walls of the wall section are part of the L-shaped cross-section of the precast concrete element. The tooth and the groove are preferably positioned over the entire height of the precast concrete element.

[0023] The tooth and groove have an isosceles triangle section, where the base of the isosceles triangle coincides with a side wall of the wall section and the equal legs extend from the side wall of the wall section. The equal legs have a length of at least 1.5 cm, preferably at least 2.0 cm and more preferably at least 2.5 cm. The perpendicular distance between the base of the isosceles triangle and the angle formed by the equal legs is at least 1.0 cm, preferably at least 1.5 cm. The tooth and groove preferably have an isosceles and rectangular section.

[0024] Alternatively, the tooth and the groove have a semi-circular section. The radius of the semi-circular section is at least 1.0 cm, preferably at least 1.5 cm and more preferably at least 2.0 cm.

[0025] A tooth and a groove are advantageous because when the precast concrete elements according to the present invention are placed next to each other, the tooth of a first precast concrete element engages in the groove of a second precast concrete element, so that at the connection between two precast concrete elements, a solid multiple barrier for the soil is obtained in a direction transverse to the retaining wall.

[0026] According to one embodiment, both legs of the precast concrete element have their own reinforcing mesh. Both the foot and the wall section are provided with a separate reinforcing mesh. The reinforcing mesh of the foot extends over at least 80% of the width and length of the foot, preferably at least 85% and more preferably at least 90%. The reinforcing mesh of the wall section extends over at least 80% of the width and height of the wall section, preferably at least 85% and more preferably at least 90%. A reinforcing mesh is a grid of bars. The bars have a diameter of at least 6 mm, preferably at least 8 mm, more preferably at least 9 mm and even more preferably at least 10 mm. The reinforcing meshes of the foot and the wall section preferably pass through each other. The reinforcing meshes are preferably connected to each other.

[0027] A separate reinforcing mesh in both legs of the precast concrete element is advantageous for absorbing stresses in the precast concrete element, especially in the corner formed by the two legs of the L-shape. In the case of a prior art simple reinforcing mesh bent into an L-shape, the reinforcing mesh exerts a tensile force from a free end of the first leg towards the corner formed by the two legs of the L and from a free end of the second leg towards the corner formed by the two legs of the L. There is no tensile force by the simple reinforcing mesh from the corner formed by the two legs of the L-shape to the free ends of the legs. This results in a high tension in the concrete at the corner formed by the two legs of the L-shape. This tension is further increased by the weight of the wall section, which also exerts a force on the corner. There is a real risk of spalling of the concrete in the corner and failure of the precast concrete element.

[0028] By placing a reinforcing mesh in both the foot area and the wall section, there is indeed a tensile force through the reinforcing mesh from the corner to the free ends of the legs. Since the reinforcing meshes extend through each other, they can penetrate deep into the corner of the precast concrete element to absorb tensions.

[0029] According to another embodiment, the reinforcing meshes are bent in each leg in the angle, formed by the foot and the wall section, over a distance of at least 10 cm, preferably at least 20 cm, more preferably at least 30 cm and even more preferably at least 40 cm, in a U-shape and away from the other leg. The bent parts of the reinforcing meshes form a tube.

[0030] The tube is a substantially beam-shaped body. The beam-shaped body preferably has a square cross-section. The minimum dimensions of the tube are determined by a useful height in the corner, measured from a reinforcing mesh in a leg to a side of the leg furthest from the reinforcing mesh, in which the tube is covered with at least 3 cm of concrete. One side of the square cross-section has a length of at least 6 cm, preferably at least 8 cm, more preferably at least 9 cm and even more preferably at least 10 cm.

[0031] The tube is a rigid element which advantageously allows moments to be absorbed relative to an axis in the longitudinal direction and through the tube. This is, for example, a moment caused by the force that the higher ground exerts on the wall section of the precast concrete element. If the concrete cannot sufficiently absorb this moment, the wall section would twist relative to the foot and crack at the angle formed by the wall section and the foot, eventually breaking.

[0032] When the wall section twists relative to the foot, the concrete in the extreme corner, formed by the wall section and the foot, is most compressed, making the concrete in the extreme corner susceptible to crumbling and spalling. By bending the reinforcing mesh in each leg in the corner, formed by the foot and the wall section, for a distance of at least 10 cm in a U-shape and away from the other leg, the reinforcing mesh lies very close to the extreme corner and exerts a tensile force towards the free end of one leg, which reduces the tension due to compression in the extreme corner and reduces the risk of spalling of the concrete.

[0033] According to one embodiment, the precast concrete element comprises a concrete reinforcement volume at an angle formed by the foot and the wall section. The concrete reinforcement volume extends over the entire length of the foot. The concrete reinforcement volume is delimited by the wall section, the foot and an inclined wall. The concrete reinforcement volume is a triangular prism. The triangular prism is preferably cast together with the foot and the wall section, so that the wall section, the foot and the concrete reinforcement volume form a monolithic whole. The concrete reinforcement volume has a height of at least 9 cm, measured from the foot and in the height direction. The concrete reinforcement volume has a width of at least 9 cm, measured from the wall section and in the width direction.The volume of concrete reinforcement is advantageous in diverting some of the weight of the wall section towards the foot, away from the angle formed by the wall section and the foot.

[0034] According to another embodiment, the concrete reinforcement volume comprises a reinforcing mesh. The reinforcing mesh is substantially parallel to the inclined wall. The reinforcing mesh projects through the reinforcing mesh in both the foot and the wall section. At one end located in the wall section, the reinforcing mesh is bent towards a free end of the wall section. At one end located in the foot, the reinforcing mesh is bent towards a free end of the foot. The reinforcing mesh in the concrete reinforcement volume extends over at least 80% of the length of the concrete reinforcement volume, preferably at least 85% and more preferably at least 90%. The reinforcing mesh is a grid of bars. The bars have a diameter of at least 6 mm, preferably at least 8 mm, more preferably at least 9 mm and even more preferably at least 10 mm.

[0035] The reinforcing mesh is advantageous for reinforcing the angle formed by the wall section and the foot. The reinforcing mesh is adapted to absorb moments about an axis in the longitudinal direction and across the angle formed by the wall section and the foot. This is, for example, a moment caused by the force that the higher ground exerts on the wall section of the precast concrete element. If the concrete cannot sufficiently absorb this moment, the wall section would twist relative to the foot and the concrete reinforcing element would be stretched in a direction parallel to the inclined wall. Concrete does not resist stretching well, and the volume of Concrete reinforcement can crack and ultimately the precast concrete element can break at the angle formed by the wall section and the foot. The reinforcing mesh exerts a tensile force opposite to the stretching, which helps prevent cracking and breaking of the concrete reinforcement volume and ultimately the precast concrete element.

[0036] A precast concrete element, in which the two legs comprise a separate reinforcing mesh, as described in a previous embodiment, and in which the precast concrete element comprises a concrete reinforcement volume, comprising a reinforcing mesh, is advantageous for forming a retaining wall with a height of up to more than 5 m, in which the retaining wall has a low top load.

[0037] A precast concrete element, in which the two legs comprise a separate reinforcing mesh and in which the reinforcing meshes are bent in the angle to form a tube, as described in a previous embodiment, and in which the precast concrete element comprises a concrete reinforcement volume, comprising a reinforcing mesh, is advantageous for forming a retaining wall with a height of up to more than 5 m, in which the retaining wall has a high top load.

[0038] According to one embodiment, the wall section is wider at the toe than at an opposite end. The opposite end is a free end of the second leg of the L-shape. This is advantageous because the lateral force of the higher ground increases closer to the toe of the precast concrete element. A wider wall section can absorb a greater compressive force.

[0039] According to another embodiment, the wall section has an equal width from the opposite end over a distance of at least 30 cm, after which the width gradually changes to the width of the wall section at the foot. This is advantageous because when using a retaining wall next to, for example, a higher path, for example, a footpath made of fired bricks, the fired bricks can be placed up to the precast concrete element, which is not possible with a wall section whose width gradually changes from the opposite end to the foot. In this case, the fired bricks would touch a lower part of the wall section. This is particularly advantageous when the precast concrete elements according to the present invention are placed side by side on a slope, where adjacent elements have different heights.The width of the wall section at the opposite end can be assumed to be the same for all precast concrete elements, but the required width of the wall section at the foot differs due to the different heights of the wall section, so that in a gradual transition according to an embodiment described above, depending on the height of a . precast concrete element, a fired brick can be placed closer or further from the wall section. This is particularly problematic for placing fired bricks at transitions between precast concrete elements. Alternatively, in the case of adjacent precast concrete elements, it could be decided to take an equal width from the wall section to the toe and allow the width to increase gradually from the toe. However, this results in a different width at the opposite end of the wall section, which, again, is impractical for placing fired bricks at transitions between precast concrete elements.

[0040] According to one embodiment, the wall section is rounded at an end opposite the foot. The end opposite the foot is a free end of the second leg of the L-shape. The rounding has a radius of at least 5 mm, preferably at least 7 mm and even more preferably at least 9 mm. A rounding with a radius of at least 5 mm is advantageous for installing a fence on a retaining wall. Such a fence is fixed to the retaining wall by means of a U-shaped or L-shaped profile. A U-shaped or L-shaped profile is obtained by bending a rectangular metal sheet. This is always with a rounding radius. The rounding of the wall section at an end opposite the foot allows the U-shaped or L-shaped profile to fit tightly to the wall section.

[0041] According to one embodiment, the foot is narrower at an end opposite the wall section than at the wall section. The end of the foot opposite the wall section is a free end of the first leg of the L-shape. The transition between the length of the foot at the wall section and the shorter length at the opposite end may be gradual or stepped. Such a foot is advantageous for forming corners in a retaining wall or for forming convex retaining walls. Convex retaining walls are retaining walls that form an arc or a circle, in which the foot of the precast concrete elements are located inside the arc or circle.

[0042] According to one embodiment, the wall section at a first side is higher than at an opposite second side. The first and second sides are opposite in the longitudinal direction. The height transition between the first side and the second side is gradual. This embodiment is advantageous for forming a retaining wall along a sloping surface, where the slope is in the direction of the retaining wall.

[0043] According to one embodiment, the foot comprises a projecting concrete reinforcement. The projecting concrete reinforcement comprises a single row of bars, placed side by side in the longitudinal direction of the precast concrete element. Alternatively, the projecting concrete reinforcement comprises two or more rows of bars. A row comprises at least 4 bars per meter, preferably at least 6 bars per meter, more preferably at least 8 bars per meter and even more preferably at least 10 bars per meter. at least 10 bars per meter. The bars have a diameter of at least 6 mm, preferably at least 8 mm, more preferably at least 9 mm and even more preferably at least 10 mm. The protruding concrete reinforcement is advantageous for integrating a precast concrete element into a concrete floor slab.

[0044] According to one embodiment, at a first side of the wall section, the distance seen longitudinally from the wall section to the foot is at least 10 cm longer, preferably at least 15 cm longer, preferably at least 20 cm longer and even more preferably at least 25 cm longer than the distance from the wall section to the foot at a second opposite side of the wall section. Such a foot is advantageous for forming convex retaining walls.

[0045] According to one embodiment, the wall section comprises openings or recesses. This is advantageous for the passage of pipes, for example, or for the integration of lighting in a retaining wall.

[0046] In the following, the invention will be described by means of non-limiting figures illustrating the invention, and which are not or cannot be interpreted as limiting the scope of the invention.

[0047] [Fig. 1] shows a perspective view of a precast concrete element according to one embodiment of the present invention.

[0048] The precast concrete element has an L-shaped section. A first leg is the foot (2). A second leg is the wall section (1). The wall section (1) and the foot (2) are substantially perpendicular to each other. The foot (2) is at least 1 cm shorter than the wall section (1) at both ends. The wall section (1) comprises a groove (4) in a second side wall (12) in the height direction. The groove (4) extends over the entire height of the precast concrete element. The precast concrete element comprises a concrete reinforcement volume (3) at an angle, formed by the foot (2) and the wall section (1), which extends over the entire length of the foot (2). In the wall section (1), there is a lifting element (5), which can be used as a hanging point for lifting the precast concrete element.

[0049] [Fig.2] shows a sectional view of a precast concrete element according to an embodiment of the present invention.

[0050] The precast concrete element is similar to the embodiment shown in [Fig.l]. The wall section (1) comprises a reinforcing mesh (6). The reinforcing mesh (6) is placed closer to a side wall of the wall section (1) on the side of the foot (2) than to an opposite side wall of the wall section (1). The reinforcing mesh (6) comprises a folded section (7). The folded section (7) is folded away from the foot (2). The folded section (7) is located at an extreme corner formed by the foot (2) and the wall section (1). The foot (2) comprises a reinforcing mesh (8). The mesh reinforcement (8) is placed closer to a side wall of the foot (2) on the side of the wall section (1) than to an opposite side wall of the foot (2). The reinforcement mesh (8) comprises a bent section (9). The bent section (9) is bent away from the wall section (1). The bent section (9) is located at an extreme corner formed by the foot (2) and the wall section (1). The bent sections (7) and (9) form a tube (10) at an extreme corner formed by the foot (2) and the wall section (1). The concrete reinforcement volume (3) comprises a reinforcement mesh (14). At one end (15) located in the wall section, the reinforcement mesh (14) is bent towards a free end of the wall section. At one end (16) located in the foot, the reinforcement mesh (14) is bent towards a free end of the foot.

[0051] [Fig.3] shows a perspective view of a precast concrete element according to an alternative embodiment of the present invention.

[0052] The precast concrete element is similar to the embodiment shown in [Fig.l] and [Fig.2]. On a first side (11) of the wall section (1), the longitudinal distance between the wall section (1) and the foot (2) is at least 10 cm greater than the distance between the wall section (1) and the foot (2) on a second, opposite side (12) of the wall section (1). The wall section (1) comprises a tooth (13) in a first side wall (11) in the height direction. The tooth (13) extends over the entire height of the precast concrete element. The wall section (1) is wider at the foot (2) than at an opposite end (18). The wall section (1) has a section (17) from the opposite end (18) with a height of at least 15 cm, in which the wall section (1) has an equal width, after which the width gradually changes to the width at the foot (2).

Claims

Claims

1. A precast concrete element for constructing a retaining wall comprising a wall section (1), a foot (2) and a reinforcing mesh, wherein the precast concrete element has an L-shaped cross-section, wherein a first leg is the foot (2) and a second leg is the wall section (1), wherein the first and second legs are substantially perpendicular to each other and wherein the width in the direction of the first leg, the height in the direction of the second leg and the length perpendicular to the L-shaped cross-section are defined, the foot (2) is at least 1 cm shorter than the wall section (1) at both ends in the longitudinal direction; both legs have their own reinforcing mesh (6, 8);characterized in that in the corner formed by the leg (2) and the wall section (1), the reinforcing mesh (6, 8) of each leg is bent over a distance of at least 10 cm in a U-shape and away from the other leg, the bent sections of the reinforcing meshes (6, 8) forming a tube.;

2. The precast concrete element according to claim 1, characterized in that the wall section (1) comprises a groove (4) in the height direction in a first side wall and a tooth (13) on a second longitudinally opposite side wall, wherein the groove (4) and the tooth (13) are complementary.

3. The precast concrete element according to one of the preceding claims 1 to 2, characterized in that the precast concrete element comprises a concrete reinforcement volume (3) at a corner formed by the foot (2) and the wall section (1), the concrete reinforcement volume (3) extending over the entire length of the foot (2) and being delimited by the wall section (1), the foot (2) and an inclined wall.

4. The precast concrete element according to claim 3, characterized in that the concrete reinforcement volume (3) comprises a reinforcing mesh (14), the reinforcing mesh (14) being substantially parallel to the inclined wall, the reinforcing mesh (14) extending through the reinforcing mesh both in the foot (2) and in the wall section (1), and the reinforcing mesh (14) being bent at one end (15) in the wall section towards a free end of the wall section and at one end (16) in the foot towards a free end of the foot.

5. The precast concrete element according to one of the preceding claims 1 to 4, characterized in that the wall section (1) is wider at the foot (2) than at an opposite end (18).

6. The precast concrete element according to claim 5, characterized in that the wall section (1) has an equal width from the opposite end (18) over a distance of at least 30 cm, after which the width gradually changes to the width at the foot (2).

7. The prefabricated concrete element according to one of the preceding claims 1 to 6, characterized in that the wall section (1) is rounded at an end (18) opposite the foot, the rounding having a radius of at least 5 mm.

8. The precast concrete element according to one of the preceding claims 1 to 7, characterized in that the foot is narrower at an end opposite the wall section than at the wall section.

9. The precast concrete element according to one of the preceding claims 1 to 8, characterized in that the wall section (1) comprises a first and a second side (11, 12) opposite in the longitudinal direction, and the wall section (1) is higher on the first side (11) than on the opposite second side (12).

10. The prefabricated concrete element according to one of the preceding claims 1 to 9, characterized in that the foot (2) comprises a projecting concrete reinforcement.

11. The precast concrete element according to one of the preceding claims 1 to 10, characterized in that on a first side (11) of the wall section (1), the longitudinal distance from the wall section (1) to the foot (2) is at least 10 cm greater than the distance from the wall section (1) to the foot (2) on a second, opposite side (12) of the wall section (1).

12. The prefabricated concrete element according to one of the preceding claims 1 to 11, characterized in that the wall section (1) comprises openings or recesses.

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