Abstract: A liquid-tight lining which is resistant to chemical attack for catch reservoirs, containers or the like of concrete. The lining includes a continuous liquid-tight impervious layer provided above the surface of the concrete. To make possible a simple and safe and repeatable testing of the tightness of the lining, a porous intermediate layer is provided between the concrete and the impervious layer. At least one sensor cable having at least two conductors is placed in the intermediate layer in such a pattern that any location of the intermediate layer is not more than a certain maximum distance away from the cable. The sensor cable is connectible to an electrical monitoring unit.

Abstract: This invention relates to a public works machine equipped with a bucket unloading device. According to the invention, this device comprises an endless member mounted for movement or translation along the jib and comprising blades, a chute disposed under the jib capable of being swept by said blades and a bucket whose section is identical to that of said chute, the shoot-bucket assembly then being completely swept by the blades. The material contained in the bucket is pushed via the shoot onto a conveyer belt which evacuates it to the rear of the machine.