FR2640296A1 - PERMEABLE CONCRETE COATING WITH WATER - Google Patents

Abstract

This coating has the following composition, in the form of a hardened concrete mixture: 300 to 400 kg of Portland cement; - 0.08 to 0.04 part by weight of binder; and - 0.3 to 0.45 part by weight of water for one part by weight of cement; - an aggregate composed of sand and ground stone ndegre (s) 7 in a weight ratio lying in a range of 5: 95 to 20: 80, the whole being substantially evenly distributed in the volume of 1 m ** o of hardened concrete mixture and, in addition, part of the cement mortar adhering to a surface of the aggregate has been removed from the surface of the hardened concrete mixture, resulting in the coating being permeable and naturally colored on the surface .

Description

The invention relates to a coating made of

  concrete that has such good water permeability that the

  pressure from the arrival of water to the soil surface, which has become a serious problem, especially in cities, can be successfully eliminated.

  Because of the generalized trend of

  banisation, the harmful effects of this latter

  are remarkable in various fields.

  Rainwater that could cross the ground can no longer penetrate as it is

  prevented from reaching the ground by pavements or cladding.

  asphalt, concrete, buildings, etc. Of

  all the harmful influences of urbanization, this

  The prevention of rainwater from reaching the ground and humidifying it has become an increasingly serious problem as urbanization has developed. In other words, as the ground surface that could be traversed by the rainwater decreases, the volume of 1 '

  groundwater decreases immediately so that its ni-

  calf decline, tree growth slows down and 1 '

  ecology of the organisms in the soil is changing.

  In addition, because of the aforementioned decrease in the water-permeable soil surface and the difficulty of

  to retain water on the surface, when the rains fall

  In a short time, the rivers overflow or the streets are flooded, which is the cause of serious difficulties although the total amount of rainwater is not so great. It is desirable that the above difficulties

find a solution quickly.

  From a different point of view, more recently, with the aim of making cities more pleasant, it has become commonplace to color sidewalks, public gardens, etc. Currently, the method to achieve this is frequently to mix various pigments with asphalt or concrete, in advance, and knead

  the mixture at the time of use: another method

  is to project different pigments on a surface so

  to color the floor covering. Given the need

  As described above, to keep the property on the ground from being traversed by the water and to retain the water, it has been envisaged to make floorings of the coatings, using water-permeable asphalt. However, the water permeable asphalt is not always satisfactory because its water permeability and water retention are not as excellent as hoped; asphalt tends to melt under the sun

  and to take charge by absorbing the foreign bodies which de-

  its water permeability: aging also acts on its resistance. As a result, the use of concrete

  permeable cement has become the object of

  cement concrete, practical to use, and excellent in permeability to

  water and water retention, is desirable.

  In addition, from the point of view of coloring, the methods mentioned above to achieve this provide an artificial visual impression different from the effect of natural colors and, therefore, it can not be said that these methods succeed in providing the 'aspect

ornamental sought.

  The object of the invention is therefore to

  come to eliminate the disadvantages outlined above.

  As a result of serious research, the inventor succeeded in producing a concrete cement coating

  which is excellent from the point of view of the property of the

  water meableness and water retention and that is

  provided with natural colors, which eliminates

  the disadvantages of the prior art.

  According to the present invention, the coating

  cement concrete consists of a hardened cement concrete mixture in which there is: 300 to 400 kg of Portland cement 0.08 to 0.04 part by weight of binder and 0.3 to 0.45 part by weight of water for one part by weight of cement, and an aggregate composed of sand and ground stone n 7 with a weight ratio in the range of 5: 95 to 20:80 which are substantially evenly distributed

  per volume of 1 m3 of hardened concrete mix, and in the

  which part of the cement mortar adhering to a surface

  this of the aggregate is removed on the surface of the hardened mixture

of cement concrete.

  It is particularly preferable for the coating--

  the ratio of sand to ground stone n 7 in a range of: 90 to 15: 85, because, when the ratio is in this range, the resulting strength is suitable for pavement for road traffic and permeability to water

  can be kept at a required value.

  In addition, it is best to choose the binder to

  from 0.015 to 0.03 parts by weight for a

  by weight of cement or choose for water 0.35 to 0.40 part by weight for one part by weight of cement. The

  amount of binder represents the amount of the solid

of resin in emulsion.

  In addition, for the balance between strength and permeability it is preferable to use the cement in an amount ranging from 320 to 370 kg per

m3 of concrete permeable to water.

  In a zone paved in accordance with the present invention, on a sidewalk, in a public garden, etc., the aggregate exposed to the surface of the coating presents the

  natural color which it possesses in itself, as a result of

  sandblasting, which gives charm to the visual impression of people watching

  sidewalk, unlike artificial visual impression-

  given by the classic colored sidewalks.

  In addition, because of the constitution mentioned above, the coating according to the invention has the same property of water retention as that of ordinary soil in the rain and produces a rapid penetration of water comparable to the effect of conventional asphalt pavements

  or a conventional concrete coating, while

  garment according to the invention has sufficient strength

  large for practical use. With a coating

  form to the invention, it is possible to obtain a water absorption rate of the order of 10-1 - 10-4 cm / s,

  typically of the order of 10 -10-3 cm / s.

  The water-permeable concrete cladding conforms

  me to the invention is remarkably different from a

  classic water permeable asphalt in this respect

  that, with the former, no absorption of foreign products

  gers does not occur, aging is slow, no softening

  is not caused by high temperature, etc. In addition, the coating according to the invention has, in spite of its strength, large voids of 10 to%. As a result, even when fine soil or sand or similar deposits have accumulated on the surface of the pavement, water and sand can pass through the voids when the rain falls so that the coating

  is cleaned without taking care of foreign bodies.

  The water-permeable concrete cladding conforms

  to the invention has a resistance which is sufficient in

  although it has large voids and permeability

  with sufficient water as explained above. Its resistance

  compressive strength is 20 to 30 MPa (resistance after

  4 weeks hardening in water at room temperature

  stant of 20 C), and its flexural strength is 2 to 3 MPa (resistance after 4 weeks hardening

  in water at a constant temperature of 20 ° C).

  The water-permeable concrete coating,

  form of the invention is obtained by the process of the invention.

  comprising the following operations: mixing, for 1 m3 of a concrete mixture, 300 to 400 kg of Portland cement, 0.008 to 0.04 parts by weight (solid part) of a binder and 0 , 3 to 0.45 parts by weight of water for a part of cement, and of an aggregate comprising the balance formed by

  sand and crushed stone no.

  killing in a range of from 5: 95 to 20:80 by weight for the purpose of

  retention of a concrete mix; casting or injection into a mold of the mixture thus obtained, curing the mixture to obtain a concrete coating, washing the surface

  coating to remove adhering mortar

  on the surface of aggregates, on the surface of the coating,

  using a sanding and sweeping machine (usually

  a blast cleaning machine). In the aggregate according to the invention, it is necessary to choose the ratio by weight of sand and ground stone n 7 in a range of 5: 95 to 20:80. The ratio 5: 95 is suitable for the production pavement pavement however

  that the ratio greater than 10: 90 is suitable for

  a coating intended for light traffic. Part of the aggregate, preferably 10 to 30% by weight of the aggregate, can be replaced by ground stone n 6 having a

  particle size of 13 to 5 mm. In this case, it appears

  a disadvantage, in that the external appearance

  the coating becomes unpleasant because the stone

  No. 6 of larger dimension coexists with No. 7 ground stone, although this is an advantage in that the strength of the coating is increased to some extent. The amount of Portland cement is chosen from 300 to 400 kg, preferably from 320 to 370 kg for 1 m 3 of complete concrete mixture, including water. The binder is added in an amount of 0.008 to 0.04 parts by weight, preferably

  0.015 to 0.03 parts by weight for one part by weight of cement.

  As binder it is possible to use any binder which is known as an additive to the cement mortar. In other words, natural or synthetic rubber for example, acrylic resin, epoxy resin, etc. can serve as

  binder. In general, the binder is added in the form of an emulsion

  if we. For example, when a binder based on rubber latex

  synthetic rubber (known as JSR TOMAC SUPER, produced by Japan Synthetic Rubber Co., Ltd., Japan, having a solid 0.45%) available on

  market is used in a quantity which is:

  the range above, resistance to 1

  can be increased from 10 to 60%. However, when the quantity

  binder content exceeds this range, the permeability to water

  is reduced considerably undesirably.

  The amount of water is chosen to be 0.30 to 0.45 parts by weight, preferably of the order of 0.35

  to 0.40 parts by weight, for a part by weight of cement.

  The permeability to water is poor when the amount

  water exceeds the upper limit of the range and, on the contrary,

  re, proper mixing can not be performed when

  the amount of water is decreased below the in-

bottom of the range.

  As a material used for sanding, that is,

  the superficial stripping operation of the aggregates, it is possible to use spherical iron (having a diameter of no more than about 2 mm) or sand (as

  silica sand or the like in particles having a dia-

  meter not greater than 0.6 mm). The material used for sand

  ge is projected onto the surface of the coating using a machine to remove the parts of the cement or mortar

which adhere to the aggregates.

Claims (5)

  1 - Concrete cement coating consisting of a hardened cement concrete mixture in which: 300 to 400 kg of Portland cement 0.08 to 0.04 part by weight of a binder and 0.3 to 0.45 part in weight of water for a part by weight of cement, an aggregate composed of sand and ground stone n '7 in a ratio by weight falling within a range of : 95 to 20:80,   are substantially evenly distributed in a volume of 1 m3 of the hardened concrete mixture, and wherein the portion of the mortar adhering to a surface of 1 '   aggregate on the surface of the hardened concrete mixture is removed.   2 - concrete coating according to claim 1, wherein the ratio of sand to ground stone n 7   is chosen to be in a range of 10:90 to 15:85.   3 - Concrete coating according to claim 1, wherein the amount of the binder is selected from 0.015 to 0.03 part by weight for one part by weight of cement.   4 - concrete coating according to claim 1, wherein the amount of water is chosen to have the value of 0.35 to 0.40 part by weight for part in weight of cement.   5 - concrete coating according to claim 1, wherein the cement is used in a range of 320   at 370 kg for 1 m3 of concrete mix.