The present invention relates to an adjustable telescopic formwork with linear or axial and radial geometric alignment for pavement construction which materials lose volume in the dehydration step until reaching the solid state. The aim is to achieve a light and resistant formwork.
In search of the prior art invention, the patent documents U.S. Pat. No. 4,202,145, DE3727780 and DE4329910 have been identified. These documents relate to telescopic formwork for paving. They are different from the present invention since they do not have an inner blade (b) to which are welded two stop bars (f) allowing their rapid attachment to the ground by a nail (g), thereby assuring their perfect tightness. This new application makes it possible to monitor all unevenness of the foundation. Existing formworks can only be levelled by lifting the slab base by means of shims and stop bars, welded or tied, leaving empty spaces without resistance (to bending/traction), areas at the lower edge of the slabs, subsequently leading to its rupture and differential settlement.
So its telescopic function allows the reposition of the initial topographic elevation at any stage of the construction or loss of volume of the materials, whether the unevenness is caused by human intervention, or caused by chemical and physical action of the materials or by the elastic movements of the foundations.
It adds that the telescopic function allows in a quick and practical way, through easy assembly and disassembly, to correct all the imperfections of the bases (natural ground, selected soils, deformable materials, etc.), as well as the radial placement to implement curves and the axial placement to implement bumps and depressions with variable topographic elevations since the formworks have different dimensions (
The present invention works preferably with the system of semi-continuous concrete/slab-foundation, with joints provided with load transfer plates, but can also be used in concrete slabs where the load transfer elements in the joints are bars or continuous reinforcements (h), which are placed through one of the openings (m), which besides allowing their fixation do not prevent the vertical movement to achieve the above described levelling.
The present invention can also be applied to deformable or resilient materials (EPS, XPS, rubbers, acoustic and thermal materials, etc.) without losing the characteristics described above, simply by the effect of placing a removable reinforcement bar (i) that is anchored to an outer plate (j) to the formwork, resting on the said deformable and resilient material (
The present invention has the following advantages over the prior art:
The present invention relates to an adjustable telescopic formwork with linear or axial and radial geometric alignment for pavement construction which materials lose volume in the dehydration step until reaching the solid state and consists in obtaining a light and resistant formwork. The innovation of the present invention relates to the fact that it is obtained by using in its manufacture various types of materials (steel, plastic, wood, etc.) of easy placement and that allows at the same time by its telescopic movement in the vertical direction to adjust accurately in the order of millimetres any pavement area, at any stage of volume reduction of the constituent materials that are confined thereof (concrete, mortar, plaster, sand/gravel stabilized, etc.).
The present invention is intended to confine various types of materials, especially cement concrete, ensuring its perfect levelling, assuring very low margins of unevenness at most 2 mm, verified by a ruler of 6 m and is intended primarily to the construction of roads, airports, ports and industrial flooring.
The present invention consists of at least two blades:
The above technical features make possible, by the present invention, the adjustment and the levelling at all stages of volume loss of the materials either by hydration of the water as by chemical and physical transformations thereof, thus ensuring the quality of a final levelling to the millimetre.
The formwork, object of the present invention, allows the correction of topographic levelling in any implementation stage of the pavements, whatever the unevenness that may occur, either by volume loss of the materials (lowering, “slump”) or by the movements of soils of the base and sub-base or for any accident during the execution (strokes with machines, for example).
The directional and vertical alignment is ensured by the hinge (d) fixed by an axis that allows the rotation in both a clockwise direction and in the reverse direction, thereby forming an accurate angle of 90 degrees on the slab base and simultaneously sealing it completely. The fact that it follows the irregularities and unevenness of the foundation prevents the passage of the constituent materials of the slab (sand, stone, concrete, etc.), preventing the occurrence of voids at the base thereof.
The technical effect of following the irregularities and unevenness of the foundation, allowing the tightness on the slab base, enables efficient placement of inductor and tightness joint elements (“water stop”) (e) that prevent the destruction of the foundations, so avoiding the disastrous pumping phenomena (“pumping”), with the consequent breakage of the slabs.
The present invention enables the exact distribution of the loads on the transmission elements (load transfer plates, load transmission bars, reinforcements, etc.). The perfect base angle obtained by these formworks increases the strength of the lower edge of the slab, allowing a more safely stress distribution, saving the slab and the foundation.
The above mentioned fixing hinges besides allowing the perfect directional and vertical alignment of these formworks also enable the connection between them easily and quickly. Since they are not apparent, they are not in contact with the concrete or other materials, not creating therefore anchor points which allow the free retraction thereof. Thereby eliminating shrinkage cracks outside the load transfer supports (load transfer plates load transfer bars, continuous reinforcements, concrete with fibres, etc.), assuring that the slabs have the shape and behaviour required in the project sizing.
This preferred embodiment is intended for the placement on resilient materials.
Note—
Number | Date | Country | Kind |
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107373 | Dec 2013 | PT | national |
Filing Document | Filing Date | Country | Kind |
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PCT/PT2014/000076 | 12/19/2014 | WO | 00 |