In many smaller towns and villages along roads, there are stormwater drainage canals into which water from roads and house roofs flows during rains. In larger cities, these catchment waters are drained through openings that are set up every few tens of meters. These drain openings are usually covered with a steel round cover that has gratings on it through which the water goes into the sewer. Such sewer gratings are often placed in front of the entrance to the basement where they collect water so that it does not enter the basement. Such gratings in front of the basement entrance have a long and narrow shape to collect water the entire width of the basement entrance. Such sewer manhole covers are usually made of iron and are expensive.
Such gutter covers could be placed above all smaller storm water channels, thus turning this space into a useful area that can be used as a pedestrian path or bicycle path. For this purpose lattice covers should be much cheaper, and therefore instead of iron they must be made as reinforced concrete slabs. Reinforced concrete is much cheaper because it contains very little expensive iron.
For this purpose, the stormwater channels (1) should be concreted as shown in the figure above, with precisely defined dimensions so that concrete slabs (2) can be easily placed in them. Each such concrete slab (2) has a series of small pyramidal openings through which water enters during rain. In order for the concrete slab (2) to be able to carry a large load on the bottom of the slab, it is necessary to install a steel reinforcing mesh (3). The openings in this concrete slab (2) are 2 to 3 millimeters wide on the upper side so that women with high narrow heels can walk on that concrete slab (2). It opens towards the bottom of the concrete slab (2) wider in the shape of a pyramid so that in winter the ice could not destroy this concrete slab (2). At low temperatures below 0 degrees Celsius, water turns to ice that expands. When ice begins to form in these openings it expands, and this expansion pushes it downwards inside the cone of the opening, and ice falls to the bottom of the channel. The bottom of the channel should be located at a depth below the freezing point of the soil, and this depends on the latitude where the channel is located. In the northern parts, the freezing point of the soil is deeper, while in the southern latitudes of the northern hemisphere, the winter depth of soil freezing is smaller.
Such a concrete slab (2) with pyramidal openings is not difficult to make.
A steel reinforcing mesh is first placed in the mold at the bottom, one to two centimeters above the bottom. Between the openings of this mesh, small pyramidal shapes are placed, which are 4 centimeters narrower at the bottom than the openings on the reinforcing mesh, and the height of such pyramidal shapes is equal to the thickness of the concrete slab (2). When the mold is prepared in this way, fiber concrete with glass threads is inserted into it, which significantly increases its strength. When the concrete dries, the mold is turned over and a solid concrete slab (2) with built-in pyramidal openings falls out of it.
Such concrete slabs (2) would be slightly lighter than concrete slabs of the same dimensions that do not have pyramidal openings, and their price would be the same as any other reinforced concrete. By placing them on the prepared concrete channels (1), the soil around them (4) would be protected from flooding during rains. In this way, the space occupied by the drainage canals along the roads would be turned into very useful areas for the movement of residents.
Other of my technical-technological analyzes and innovations can be seen in this book.