FR2503207A1 - Resin modified heavy oil to plug expansion gaps in concrete paving - preventing moisture ingress and subsequent erosion - Google Patents

Abstract

Gaps or slots between concrete slabs are filled with a mass of plastic or elastic material injected at the base of the gaps between the slabs to flood the gaps below the level of a conventional capping strip. Specifically the filler is injected by holes typically 1-2 cm bore drilled obliquely through the slabs to their lower edges to reach any substrate cavities and to flood the slots or gaps from below. Pref. the filler material is a 3:1 blend of a heavy coal tar oil, specifically a chrysene oil (C18H12) or other aromatic oil, and a fluid resin, pref. epoxy or PVC. Used esp. for plugging expansion slots typically 1 cm wide and 4 cm deep in runways etc. to prevent ingress of moisture and subsequent erosion or discharge of mud due to local traffic pressures.

Description

 The subject of the present invention is the establishment by injection or other of a plastic or elastic mass between the sub-base of concrete slabs and their support, and between concrete slabs in a void created between them by sawing. prior to the construction of the structure.

 It is known that, during the construction of the areas of reinforced concrete, a separation of the masses of reinforced concrete is carried out by sawing it at regular or known or other intervals, so as to allow the expansion play reinforced concrete.

 This sawing is a few millimeters thick over the entire height of the reinforced concrete. In its upper part, there is a rebate about 1 cm wide by about 4 deep to allow the establishment of a bead of mastic or rubber molded to form a seal and prevent water infiltration under reinforced concrete.

 I1 is known that over time these joints degrade, that water penetrates through the voids between slabs and comes to wet the under layer of the reinforced concrete thus causing cavities which are as many weak points where the concrete can break during the passage of aircraft or flapping of slabs.

 It is also known that, in rainy weather, during the passage of aircraft or the flapping of the slabs, the cavities thus defined fill with mud and empty under pressure, thus aggravating the scour phenomenon described above.

 The establishment of an elastic or plastic mass between the underside of the reinforced concrete and its support in the scouring cavities under the voids created by sawing between concrete elements makes it possible to avoid this phenomenon.

The present invention overcomes these drawbacks by the establishment of a plastic or elastic mass.
a) Under the slab, at the level of the voids resulting from the sawing of the concrete and the scouring of the water if necessary to act as load distribution at the level of the sawing crack.

 b) In the vacuum created by sawing to protect the caulking product put in place in the upper part of the joint against rising mud.

 c) The assembly then behaves like a joint placed under the slabs.

 The subject of the invention is also an injectable elastic mass for grouting the slabs of a concrete area by their underside, such as an airport runway.

 This mass consists of an aromatic oil added with polyvinyl chloride or epoxy resin, preferably in the proportions of 75% - 25%, or by a coal pitch oil, such as chrysene oil C18 F 12 added in the same proportions as above of polyvinyl chloride or an epoxy resin.

 The injection of this elastic mass is preferably done by drilling obliquely from the surface of each slab to its underside. The mass spreads under the tiles and rises in the void created between the tiles to the channel intended to receive the seal.

 The plastic mass can be injected cold or preferably hot, 500 for example.

 There is shown in section in the accompanying drawing an example of filling the joints between two adjacent slabs of a concrete covering.

 The tiles shown by way of example are tiles 1 and 2, having a surface joint 3 with a thickness of 1 to 2 cm filled with a material 4 of a usual type, and in the mass a gap 7 from 2 to 5 mm, at the base 5 of which opens at least one oblique bore 6 of 1 to 2 cm in diameter made from the surface of the slab.

 The elastic mass according to the invention is injected through the holes 6 through the slabs 1 and 2 until it spreads under the slabs and fills the entire gap 7 between the slabs. This mass constitutes a protective buffer for the joint 3 and prevents its deterioration when rocking movements are exerted on the slabs due to the pressures to which they may be subjected in chain.

Claims (7)

 1. Method of placing a plastic or elastic mass against the underside of a concrete slab as well as in the gap between these slabs, consisting in injecting a plastic or elastic mass under the slabs until this mass goes up in the interstices between slabs to the surface slot receiving the usual seals.  2. Method according to claim 1 characterized in that the injection is done by holes obliquely made in the thickness of the slabs from their surface to the underside.  3. Injectable mass for grouting the slabs of a concrete area, characterized in that it consists of a homogeneous mixture of heavy coal pitch oil and fluid resin, in respective proportions of approximately 75% and 25, or others.  4. Mass according to claim 3 -characterized in that the oil is a --chrysene oil.  5. Mass according to claim 3 characterized in that the resin is an epoxy resin.  6. Mass according to claim 3 characterized in that it consists of a mixture of aromatic oil and polyvinyl chloride.  7. Mass according to claim 3 characterized in that it consists of a mixture of aromatic oil and epoxy resin.