CS225801B2 - Road surface with thermally insulating layer between subsoil and road cover - Google Patents

Abstract

The substrate is intended for roads, taxiways, etc. The thermal insulation layer inserted between the subgrade and the road surface is made of lightweight concrete. The insulation layer can be reinforced. It can be made in the form of rectangular prefabricated panels. The side walls of the panels can be provided with corrugations or teeth.

Description

The invention relates to roadways, for example roads, aircraft taxiways, railway embankments, with a heat-insulating layer between the ground and the roadway cover.

If the subsoil contains cohesive soil, the ingress of cold, as is known, results in ice lenses in the soil, which are increasingly larger and lead to irregular lifting of the road, but later become more dangerous when melting because they soften the subsoil and greatly reduce its load capacity. In the absence of support, the actual road construction becomes overwhelmed and consequently causes considerable damage; it is known in road construction and also in railway construction.

Therefore, when rebuilding the road for land transport, it is particularly important to ensure that coherent soil is replaced by insensitive gravel-sand in the area of subsoil freezing, ie a carefully built-in anti-freeze layer is proposed, which is obviously very expensive.

More recently, there have been efforts to save. A gravel layer of 30 cm to 50 cm in thickness is dispensed with and special plastic sheets are laid on the ground body instead. The plastic is foam polystyrene or polyurethane. With a thickness of 2 cm to 4 cm, this foam provides good thermal insulation, my very low modulus and lower strength properties. Greater elastic deformation compared to the gravel layer.

This is a very disadvantageous circumstance.

Furthermore, foam plastics are heat sensitive, which does not allow the application of a hot bituminous composition. A sand-and-gravel protective layer between the foam and the bituminous support layer is therefore required.

It is therefore an object of the invention to achieve an economical improvement over the prior art by providing a heat insulating layer at the same time as the carrier layer.

This is possible when using heat insulating materials with a modulus of elasticity E of 40,000 kp

9 2 2 in tin up to 80 000 kp / c and a compressive strength of 30 kp / cm to 50 kp / cm. Lightweight concrete meets the requirement of thermal insulation and can be designed as a supporting layer at the same time. Lightweight concrete can be reinforced to increase load-bearing capacity.

If lightweight concrete is used, for example in road construction, as a backing layer, usually as a backing layer, a good connection with the toping layer is required.

It is possible to lay a concrete pavement on a lightweight concrete with a good connection and also the application of bituminous cover does not cause any problems. Lightweight concrete resists heat. Previous coatings of bituminous material improve adhesion. The foamed concrete can be installed both on site and in the form of prefabricated slabs. Due to the bending stresses during transport, when using prefabricated lightweight concrete slabs, they should be laid across the road axis. In fact, when laying in the longitudinal direction, there is a danger of creating steps. Furthermore, when using prefabricated boards, the joints in the area of the center of the road or at the edges of the roadway need to be provided. In order to ensure a safe transfer of transverse forces in the joint area, lightweight concrete slabs should be provided with corrugated teeth at the edges, thereby largely eliminating the peeling of the mortar sealing from the joint edges that were poured after laying the slabs.

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For better laying of the lightweight concrete slabs on the adjoining ground, it is necessary to make a sloped sand bed. Through this sand bed, the moisture of the lightweight concrete slabs can be exchanged. However, in particular cases, cement or bituminous mortar beds may be preferable.

An exemplary embodiment of the subject matter of the application is shown in the accompanying drawing, in which Fig. 1 is a cross-section of a concrete pavement cover; Fig. 2 is a cross-section of a bituminous pavement cover;

As can be seen from FIG. 1, the reinforced heat-insulating layer 2 is deposited on a pre-fabricated bed 2. The concrete cover and the roadway produced by a conventional manufacturing process are applied thereon. Prefabricated slabs, such as reinforced cellular concrete slabs, are laid transversely to the road axis.

Referring to FIG. 2, a bituminous coating 6 is applied to the reinforced cellular concrete slab. Immediately placed on it is a bituminous roadway cover consisting of an upper supporting layer 2 and a cover itself.

Fig. 3 shows an embodiment of the joints of lightweight concrete slabs. Lightweight concrete slabs exhibit ripples 6 or cogs at their edges. The joint is covered with cement mortar 2 ·

Claims (5)

The invention Road substrate with a thermally insulating layer between a substrate and a road cover, characterized in that the thermally insulating layer (3) is made of lightweight concrete. 2. The substructure according to claim 1, characterized in that the thermally insulating layer of expanded concrete is provided with reinforcement. Road substrate according to claim 1 or 2, characterized in that the road cover (1) and the heat-insulating layer (3) are bonded together. Road substrate according to one of Claims 1 to 3, characterized in that the heat-insulating layer (3) consists of reinforced or unreinforced rectangular prefabricated concrete slabs, the longitudinal walls being laid transversely to the longitudinal direction of the road. Road substrate according to claim 4, characterized in that the adjacent side walls of the lightweight concrete slabs of the heat-insulating layer (3) are provided with corrugations (6) or gearing.