Patent Application
20230407652
The present invention is directed to a system and a method for concrete forming using a self-driven formwork machine. The self-driven machine is provided with a lifting system, for lifting objects from the ground like a rebar reinforcing cage, such that the use of cranes is avoided, hence, construction cost and execution time, are greatly reduced.
The present invention is preferably used for constructing pillars for highways, in particular for constructing a capital or lintel on top of a pillar, although it can also be used for constructing other overhanging concrete structures.
Concrete forming requires the use of formwork including couplable panels and supports that are manually assembled together to configure a mold, inside which concrete is poured. Typically, before pouring concrete, a rebar reinforcing cage is placed inside the mold such that an internally reinforced concrete structure is obtained. Once the concrete is cured, the formwork is disassembled and moved to the next construction site, and the casting process is repeated as many times as necessary. Therefore, formwork forming is a time-consuming and dangerous task, and require excessive manpower for assembling and disassembling the formwork.
In the particular case of constructing overhanging concrete pieces, for example capitals or lintels, large cranes with spreader beams are conventionally used for moving formwork panels and supports, for assembling and disassembling the formwork structure, and in particular for lifting from the ground and positioning the rebar reinforcing cage.
However, the use of cranes is extremely expensive, inefficient and cumbersome, and require extremely well-trained human operators.
The drawings of the U.S. Pat. No. 3,595,514 illustrates the complexity of using cranes with spreader beams, for the construction of large overhanging reinforced concrete pieces.
Furthermore, the use of cranes with requires a large free space around the construction site, for installing the crane on the ground and for moving the crane's arm. However, in some construction works have to be carried out in confined spaces due to the presence of nearby constructions or buildings, for example for constructing a highway in between existing highways, where cranes cannot operate freely.
In accordance with one or more embodiments of the present invention, an object of the present invention is the provision of an equipment and a methodology for constructing overhanging (cantilevered) concrete structures, preferably capitals, which avoids the use of cranes in order to reduce construction cost and execution time.
A further object of the present invention is the provision of an equipment and a methodology for constructing overhanging (cantilevered) concrete structures, preferably capitals, in narrow spaces confined between nearby highways or buildings, that are not accessible for conventional cranes.
In particular, an aspect of the present invention refers to a formwork system that comprises at least one formwork machine which in turn comprises a formwork supporting structure, at least a self-driven vehicle, and at least an extendable and retractable mechanism mounted on the self-driven vehicle coupled or couplable with the and at least an extendable and retractable mechanism, such that the formwork supporting structure can be raised and lowered above the self-driven vehicle.
The system further comprises a set of formwork panels that can be attached to the formwork supporting structure, to configure a mould having the shape of the concrete piece like a capital to be constructed.
The formwork system further comprises a lifting system supported by the formwork supporting structure, such that, the lifting system is raised and lowered together with the formwork supporting structure. The lifting system is configured for lifting objects from the ground like formwork panels and a rebar reinforcing structure, and for placing the rebar reinforcing cage inside the mould.
In a preferred embodiment, the lifting system comprises a davit operated by a hydraulic cylinder.
Preferably, the extendable and retractable mechanism is configured for raising and lowering the formwork supporting structure with respect to the ground, when the self-driven vehicle rest on the ground. Preferably, the extendable and retractable mechanism is configured for raising and lowering the formwork supporting structure in a vertical direction or in a direction with a vertical component. The formwork supporting structure is raised and lowered right above the self-driven vehicle, preferably along an axis orthogonal to ground and parallel to the axis of the pillar, so that all construction work can be carried out close to the pillar and below the overhanging concrete structure to be constructed, such that, there is no need to invade nearby areas or other adjacent highways.
Preferably, the self-driven vehicle is a tracked vehicle, but other type of vehicles, like wheeled vehicles suitable for this purpose, are also included in this invention.
The formwork supporting structure is fitted with coupling means, configured for coupling the formwork supporting structure with a pillar on which the capital is to be formed. Furthermore, the formwork supporting structure is a self-supporting structure configured to remain coupled by itself with a pillar in a known manner during the time required for the concrete to cure.
Once the formwork supporting structure is attached to a pillar, the extendable and retractable mechanism is uncoupled from the formwork supporting structure, so that, in practise a set of formwork supporting structures can be provided, and one machine formed by the self-driven vehicle and an extendable and retractable mechanism mounted on the self-driven vehicle, can be used to raise and lower the formwork supporting structures when required as the capitals are being constructed.
Preferably, the formwork supporting structure is rotatable above the self/driven vehicle and about an axis orthogonal to the ground. More preferably, the formwork supporting structure and the extendable and retractable mechanism are jointly rotatable about an axis orthogonal to ground.
In a preferred embodiment, the self-driven vehicle has a horizontal platform, and the formwork supporting structure and the extendable and retractable mechanism, are jointly movable, for example rotatable on the self-driven vehicle's platform, in order to be able to get a good balance when the equipment is transported for example on a gondola truck.
In a preferred embodiment, the extendable and retractable mechanism is a scissor lift operated by a hydraulic cylinder. In other preferred embodiments, other types or mechanisms like telescopic hydraulic cylinders, can alternatively be used.
Preferably, the formwork system comprises first and second formwork machines as the one described above, and formwork panels attachable to the formwork supporting structures of the first and second formwork machines, when the first and second formwork machines are coupled to a pillar for forming a capital on top of it. Therefore, the mould is formed by the two formwork supporting structures and the set of formwork panels.
The lifting system comprises a first davit operated by a first hydraulic cylinder supported by the formwork supporting structure of the first formwork machine, and a second davit operated by a second hydraulic cylinder and supported by the formwork supporting structure of the second formwork machine.
Another aspect of the present invention, refers to a method for constructing a capital on top of a pillar installed on the ground. The method comprises the steps of:
moving first and second formwork supporting structures close to a pillar, for example in a direction transversal to the axis of the pillar and at ground level or close to it,
coupling first and second formwork structures to each other at ground level, in order to obtain a more stable structure, such that a pillar is in between the first and second formwork structures,
raising together the first and second formwork supporting structures up to the level of the upper end of the pillar in a direction preferably parallel to the axis of the pillar,
coupling the first and second formwork supporting structures to the pillar, and
attaching formwork panels to the first and second formwork supporting structures to configure a mould having the shape of the capital to be constructed.
Preferably the first and second formwork supporting structures, are raised from a self-driven vehicle resting on the ground, and by means of an extendable and retractable mechanism mounted on the self-driven vehicle, such that first and second formwork supporting structures are raised above the self-driven vehicle, and below a cantilevered part of a concrete piece to be obtained.
In the method of this invention, formwork panels and a rebar reinforcing cage are lifted from the ground by means of a lifting system supported by the first and second formwork supporting structures. The lifting system lifts the rebar reinforcing cage above the first and second formwork supporting structures when these are coupled to the pillar, and then places the rebar inside the mould previously formed. Then, fresh concrete is poured inside the mould.
The lifting system can also be used for any other secondary tasks required for the construction of a capital, that would typically involve the use of cranes.
At this stage, the extendable and retractable mechanism used for raising the first and second formwork supporting structures, are uncoupled and moved away with the self-driven vehicle to be used in another pillar.
Once the concrete is cured, the formwork panels are disassembled and the first and second formwork supporting structures are lowered.
Some advantages associated to the formwork system described in this invention, are listed below:
Preferred embodiments of the invention are henceforth described with reference to the accompanying drawings, wherein:
Preferably, first and second self-driven vehicles (3a,3b) in this implementation are tracked vehicles, that do not require rails or conditioned surfaces.
Preferably, first and second extendable and retractable mechanisms (4a,4b), are configured for vertically raising and lowering first and second formwork supporting structures (5a,5b) above the self-driven vehicle and along respective axis (Xa,Xb) parallel to the axis (X) of a pillar (9) on top of which a capital (10) is to be constructed.
In the exemplary implementation shown in the figures, first and second extendable and retractable mechanisms (4a,4b), are scissor-type lift operated by a hydraulic cylinder that perform the vertical movement along axis (Xa,Xb). This extendable and retractable mechanisms (4a,4b), are capable of elevating the formwork supporting structures (5a,5b) up to 30 meters above the ground and preferably are remote controlled, such that the formwork supporting structures (5a,5b) can be easily and rapidly elevated to the required height of each pillar (the height of the pillars varies along the highway trace), and to the curvature of the highway trace, which otherwise would be too slow and complicated using cranes.
In addition, each formwork machine (2a,2b) is provided with a lifting system (6a,6b) supported by the respective formwork supporting structure (5a,5b). Each lifting system (6a,6b) is configured for lifting objects above the formwork supporting structure (5a,5b).
In the example shown in the figures, the lifting system (6a,6b) comprises first and second davits (7a,7b) articulately attached on top of the formwork supporting structure (5a,5b), and operated respectively by first and second hydraulic cylinders (8a,8b). A transversal beam (16) is supported at its ends by the first and second davits (7a,7b), and is fitted with motorized hoist (17a,17b) and the required cables.
As it can be observed in
Each formwork machine (2a,2b) is fitted with coupling means configured for coupling the formwork supporting structures (5a,5b) with the top end of a pillar (9) preferably vertically installed in the ground (13). These coupling means are realized in this implementation, as clamping members (14) pivotally mounted in the formwork supporting structures (5a,5b), and operated by hydraulic cylinders (15) to pivotally move between a clamping position (shown in
Additionally, each formwork machine (2a,2b) is provided with a ladder (18a,18b) formed by several ladder segments articulately joined between them, and coupled with the formwork supporting structures and the self-driven vehicles, as shown in
The formwork supporting structures (5a,5b) can be coupled and uncoupled from the respective extendable and retractable mechanism (4a,4b), and the formwork supporting structures (5a,5b) are configured as self-supporting structure that can remain coupled by themselves to a pillar (9), once the formwork supporting structures (5a,5b) are uncoupled from the extendable and retractable mechanisms (4a,4b).
As shown in
Each of the first and second self-driven vehicles (3a,3b) has a horizontal platform (21a,21b), and the formwork supporting structure and the extendable and retractable mechanism are jointly movable sideways on the respective self-driven vehicle's platform, as indicated by the arrows in
Furthermore, the formwork supporting structures (5a,5b) alone or together with the extendable and retractable mechanisms (4a,4b), are jointly rotatable about an axis orthogonal to ground (13), such that the formwork supporting structures (5a,5b) can be accurately positioned according to the curvature of the highway track.
