FR2583743A1 - Lightweight concrete based on vegetable aggregates, residues from agricultural and forestry farming - Google Patents

Abstract

The invention is intended to define the preparation of a lightweight concrete, for use as a material of construction, consisting of a mixture of hydraulic binder with vegetable aggregate residues from agricultural or forestry farming, which are suitably prepared, from various common additives and water. These aggregates may be residues of agricultural farming waste, of cereal or forage plant waste or of tree felling waste in a forestry environment. This lightweight concrete may be reinforced and employed in all cases as a building element.

Description

Lightweight concrete, based on plant aggregates, residues from agricultural and forestry holdings.

Concrete consists of artificial agglomerates, joined together by a hydraulic binder; they can be armed or prestressed.

 Among the special concretes are light concretes, either cellular concretes (vermicular, cavernous, etc.) or obtained with light aggregates.

 These latter, in addition to their lightness advantages, great qualities of thermal and phenolic insulation, and are suitable for the manufacture of blocks, concrete blocks, panels, walls, partitions, etc.

 Apparently the materials currently used are distinguished from products such as phenolic foam, plastics, etc. or natural products such as cork, giving results whose mechanical qualities are those of concrete, with in addition the lightness of thermal, acoustic and fireproof qualities.

 Unfortunately cork, a natural product, is extracted only from a few privileged countries and the cost of transport makes it expensive to use.

 The new idea is to make light concrete of the same qualities, but using local products from agriculture, whatever the natural environment considered (temperate, tropical world, etc.).

 The present invention aims to define the production of a light concrete, consisting of a mixture of hydraulic binder with plant aggregates, exploitation residues of agricultural or forestry products, suitably prepared, and water.

 To these basic constituents can be added, depending on the performance required, fillers, dyes, adjuvants and natural aggregates.

 Tests have verified that products of plant origin, pectocellulosic (pectose, flax, cantor, ramie, bamboo, etc.) or lignocellulosic (lignite, wood fiber, jute, cereal straw, etc.) can be used as aggregates. ).

 By way of non-limiting examples, these agricultural and forestry residues can be s - agricultural waste such as: sugar cane (bagasse) banana trunks, corn stubble, sisal, jute, flax, hemp, etc. .

- cereal or fodder plant waste such as: rice husks, fodder, wheat stubble, barley, rye, oat husks, hay.

- logging waste in a forest environment such as bamboo, trees, branches, bark, etc.

 The recovered material must be crushed, crushed or shredded according to its nature, in order to obtain grains of coherent and continuous particle size, and fibers intersecting during kneading.

 According to the present invention, an example of a preparation composition can be summarized as follows: a hydraulic binder, either an artificial Portland cement, or any other, to which a part of hydraulic lime can be added.

- grain aggregates or a mixture of grains and fibers.

The grain size is an important factor that determines the quantity
t of dough required for coating.

The dosage is carried out in volume, for example from 1 to 3 times the volume
of wax according to the final density required.

- adjuvants and plasticizers in precise dosage t they are necessary for the coating of aggregates and moreover have a hydrophobic character.

 The air entrainer and setting accelerator must be precisely cut out, either by prior dilution, or evenly distributed in the concrete.

- water, the precise dosage of which guarantees the correct c @ sion of the material.

 It must be optimized according to the paste to be obtained.

- The duration of mixing depends on the coating and the composition of the concrete, it can vary from 2 to 10 minutes depending on the speed of mixing.

 The introduction of common aggregates remains compatible with this process, for example an addition of sand, basalt, pozz @ lane, etc. improves certain qualities at the expense of others.

 Appropriate reinforcements (metallic, glass fibers, wefts, skins, etc.) make it possible to improve the uses for large-sized panels or products.

 Coatings are possible for these products, even in contact with the outside.

 These concretes can be used, in all cases, as construction elements, such as for example: - partitions, ceilings, floors, canes, screeds, walls ...

- blocks, concrete blocks, slabs, firebreak panels ...

- pipes, thermal, acoustic insulation, agglomerated ...

These applications are not limiting and generally require some specific and particular feasibility tests.

Claims (1)

OAT, hay, etc. CLAIMS rice husks, fodder, wheat stubble, barley, rye, husks - of cereal waste or fodder plants such as: banana trunks, corn stubble, sisal, jute, flax, hemp - agricultural waste such as 1 cane sugar (bagasse), -2- Aggregates, according to claim -1-, consisting of residues for example - and of water - of various suitably prepared forestry additives - of vegetable aggregates residues of agricultural holdings or - of hydraulic binder  -1- Lightweight concrete, especially for the use of building materials, consisting of a mixture 8  trees, branches, barks, etc.  - logging waste in a forest environment such as: bamboo,  -3- A process for preparing aggregates, according to claims -1- and -2-, consisting of grinding, crushing or shredding the residues according to their nature, so as to obtain grains of coherent and continuous particle size or fibers between mixing with mixing, which can then be treated with common adjuvants or plasticizers.  4 A method of preparing light concrete, according to claims -1-, -2- and -3- characterized in that it consists in mixing the hydraulic binder, the aggregates prepared in the ratio of 1 to 3 volumes of cement, additives, adjuvants, common plasticizers etc ..., in very precise dosage, water in precise dosage to within 1P, then to mix at speed and time set so as to obtain a compact paste with optimized consistency according to the results to be obtained . The introduction of common aggregates such as sand, basalt, pozzolan etc. remains compatible with this manufacturing process.  - blocks, concrete blocks, slabs, firebreak panels ...  - partitions, ceilings, floors, canes, screeds, walls,  -5- Construction elements such as 8  agglomerated ...  - pipes and thermal and acoustic insulation, essentially consisting of light concrete according to claims 1, 2,3 and @@ characterized in that, during manufacture, may be optionally embedded in the mass of suitable metallic reinforcements, fiberglass, wefts, skins, etc.