PROTECTIVE COVER OF PRECAST CONCRETE MEMBER
The object of this invention is a protective cover of a precast concrete member, which comprises a plastic part to be installed at least partly on top of the precast concrete member.
The invention thus relates to precast concrete members and more particularly to their protection at the factory, during transport and at the worksite before installation. Precast concrete members are exposed to the weather and to abrasion from lifting slings, etc.
A precast concrete member can refer to a simple cast concrete element, the thickness of which is typically approx. 15-25 cm, or to a so-called sandwich element, in which an insulating layer is between two precast concrete elements. This invention is not limited to these options or to these dimensions.
Nowadays precast concrete members are most generally protected with a plastic film, which is tightly against the surface of the precast concrete member. A drawback in the use of a tight plastic film is that moisture is not able to evaporate. Additionally, a thin plastic film does not offer sufficient mechanical protection for the abrasion of hoisting slings and especially of hoisting chains. Furthermore, during transport and at the worksite the precast concrete member are easily chipped on their corners. For example, an installed balcony wall member chips easily on is upper edge when construction waste is tipped out of the building with wheelbarrows. There are numerous other situations also in which a precast concrete member is easily damaged.
The purpose of the invention is to achieve a protective cover of a precast concrete member, to which the aforementioned drawbacks are not attached. The protective cover of a precast concrete member according to the invention is characterized in that the plastic part is essentially U-shaped and elongated, and in that it can be installed on top of the edge, more particularly on top of the top edge, of the precast concrete member essentially on the whole length of the edge such that the base of the U sits above the edge and the flanks of the U immediately against the sides of the member.
One preferred embodiment of the protective cover of a precast concrete member according to the invention is characterized in that inclined or straight protrusions are formed on the inside surface of the shanks of the essentially U- shaped plastic part, the tips of which are against the side surface of the precast concrete member, in which case ventilation channels remain between the protrusions.
Another preferred embodiment of the protective cover of a precast concrete member according to the invention is characterized in that the base of the U- shaped plastic part is formed to be at least partly corrugated in its cross-section, in which case it can be fitted to precast concrete members of different thicknesses.
Yet another preferred embodiment of the protective cover of a precast concrete member according to the invention, which comprises two concrete layers and the insulating layer between them, is characterized in that a U-shaped plastic part is installed on top of the top edge of both concrete layers, and in that a protective film or protective paper or similar is fixed between these plastic parts to protect the insulating layer.
One of the advantages of the invention that can be mentioned is that the protective cover is appreciably more durable than earlier and thus offers better protection. In addition, its installation is extremely easy. Since the protective cover according to the invention is ventilated, the precast concrete member does not become wet. Another advantage that can be mentioned is that the protective cover can easily be re-used.
In the following, the invention will be described in more detail by the aid of some preferred embodiments with reference to the attached drawings, wherein
Fig. 1 presents a partially sectioned view of the top part of a simple precast concrete member and the protective cover installed on top of it.
Fig. 2 presents a partially sectioned view of the top part of a sandwich-structure precast concrete member and the protective cover installed on top of it.
Fig. 1 thus presents a simple precast concrete member 1 and the elongated, plastic protective cover 2 installed on top of it. Thus the top edge of the precast concrete member is presented in the drawings, but the other edges of the member can be just as well protected with the protective cover 2 according to the invention.
The protective cover 2 is preferably a plastic profile that essentially retains its shape, which can be manufactured from solid plastic or similar, and the length of which can be e.g. approx. 60-600 cm, but other dimensions are possible depending on the dimensions of the precast concrete member. The length can e.g. be fitted according to the wishes of the customer, according to the lifting lugs of the member, etc. The plastic protective profile 2 functions during transportation as a protection against, among other things, the abrasion of chains and slings and also as collision protection during, among other things, transportation and lifting. In addition it functions as a ventilating weather protector during transportation from the factory, storage and construction before the final weather protection provided by the building. The protective cover is, of course, removed before any finishing work, but it can be used again, which is an advantage compared to the current solution.
The protective cover 2 according to the invention is thus a plastic profile, in which is a base 2' and shanks 2", that is U-shaped in its cross-section. In its static state the shanks 2" approach each other. When installing the protective cover on top of the precast concrete member, the shanks must thus be spread slightly apart. This produces compressive friction against the sides of the precast concrete member, in which case the protective cover stays in its position better. The shape of the protective cover reinforces it and improves its grip on the member.
The base 2' of the protective cover is made to be at least partly corrugated, in which case it stretches if necessary if the precast concrete member is thicker. Typically these types of precast concrete members are 15-25 cm thick and the same protective cover can, as a result of the base solution according to the invention, be used for these concrete thicknesses.
Protrusions 3 are formed essentially on the whole length of the protective cover
on the inside surface of the shanks 2" of protective cover 2, the tips of which are against the side surface of the precast concrete member, in which case ventilation channels 4 remain between the protrusions.
Fig. 2 presents a sandwich-structured precast concrete member 1 according to the invention, which comprises two concrete layers 1 and the insulating layer 5 between them. This kind of protective cover of the member is made according to the invention such that a plastic profile (protective cover) 2 that is U-shaped in its cross-section is installed on both concrete layers 1. On the top surface of both protective covers are fixing elements or adhesive 6, to which a protective film or protective paper 7 can be fixed to protect the insulating layer 5. The U- shaped protective covers 2 can in principle be the same type as in the embodiment presented in Fig. 1 , but the shank of the U on the side of the insulation is preferably shallower than the other shank, which facilitates installation, because the shank on the side of the insulation does not need to sink deep into the insulation. In addition, the shank on the side of the insulation 5 can be slightly sharp, which facilitates its installation inside the insulation, as is presented in Fig. 2.
It is obvious to the person skilled in the art that the invention is not limited to the embodiments described above, but that it can be varied within the scope of the claims presented below. Thus a more specific plastic material and shape of the protective part according to the invention can be selected by a person skilled in the art according to each specific need, however within the scope of protection as defined in the claims. Corner reinforcers or bead reinforcers can, if necessary, also be installed on the comers of the protective part to provide extra protection against abrasions from lifting slings or lifting chains.