Easily renovated expansion joint for a concrete slab formwork system
An expansion joint ( 1 ) for a concrete slab formwork system, said joint comprising first and second longitudinal elements ( 2, 3 ), arranged side-by-side in the same horizontal plane, and intended to each form an integral part with an upper and horizontal edge of a concrete slab, the first and second longitudinal elements ( 2, 3 ) comprise arrangements ( 5, 6, 7 ) opening on their upper horizontal walls and enabling at least a portion ( 2 a, 3 a ) of each of the first and second longitudinal elements ( 2, 3 ) to be withdrawn for replacement thereof. The first longitudinal element ( 2 ) comprises a stack of three layers of material ( 2 a, 2 b, 2 c ), with an intermediate layer ( 2 b ) having a smaller width than that of the two other layers ( 2 a, 2 c ) such that the first longitudinal element ( 2 ) has a U-shaped cross-section, and the second longitudinal element ( 3 ) comprises a stack of three complementary layers of material ( 3 a, 3 b, 3 c ), with an intermediate layer ( 3 b ) having a larger width than that of the two other layers ( 3 a, 3 c ) so as to form a transverse projection that is able to fit in the recess of the U-shape of the first longitudinal element ( 2 ).
1. An expansion joint configured for placement between first and second concrete slabs positioned adjacent thereto, the expansion joint defining an air space that absorbs variations in volume of the first and second concrete slabs under an action of shrinkage, said joint incorporating first and second longitudinal segments positioned side by side in a same horizontal plane, and being configured to each be integral with an upper and horizontal edge of the first and second concrete slabs, the first longitudinal segment being secured to a vertical separation means between the first and second concrete slabs defining a vertical plane horizontally offset with respect to a vertical plane defined between the first and second longitudinal segments such that under the action of shrinkage of the first and second concrete slabs, the first and second longitudinal segments move apart from each other but still remain bearing against one of the first and second concrete slabs, the first and second longitudinal segments comprise fittings opening at upper horizontal walls of said first and second longitudinal segments, and that enable a removal of at least a removable part of each of the first and second longitudinal segments, for replacement of said removable parts; wherein the first longitudinal segment comprises a stack of three layers of material, with one intermediate layer having a smaller width than the other two layers, such that the first longitudinal segment has a U-shaped cross section, and the second longitudinal segment comprises a stack of three complementary layers of material, with one intermediate layer having a greater width than the other two layers, so as to form a transverse projection configured to fit into the hollow of the U-shaped shape of the first longitudinal segment.
2. An expansion joint according to claim 1 , wherein the fittings take the form of apertures vertically traversing at least the removable part of each of the first and second longitudinal segments and rods inserted into the said apertures, with lower extremities integral with a fixed part of the expansion joint and threaded upper extremities able to accommodate tightening devices, for the removable fixation of the said removable part of each of the first and second longitudinal segments.
3. An expansion joint according to claim 1 , wherein the removable parts of the first and second longitudinal segments have opposing faces incorporating complementary sinusoidal profiles.
4. An expansion joint according to claim 1 , wherein at least the removable part of each of the first and second longitudinal segments is made of a polymer material, or of a composite material made from a polymer material.
5. An expansion joint according to claim 1 , wherein the second longitudinal segment is composed of at least two parts secured to each other via a removable means of fixation.
6. An expansion joint according to claim 5 , wherein the first longitudinal segment is secured to the vertical separation means via a removable means of fixation.
7. An expansion joint according to claim 5 , wherein the first longitudinal segment is composed of at least two parts secured to each other via removable means of fixation.