METHOD FOR OBTAINING RECYCLED AGGREGATES, MATERIALS AND PRODUCTS FOR CONSTRUCTION BY THE RECYCLING OF CONSTRUCTION AND DEMOLITION WASTE

Abstract

This request is about a process for assembling recycled aggregates from construction and demolition waste, such as debris and waste generated within the construction industry, such as: bad mixtures of concrete, bricks, tiles, stones, plasters, ceramics; as well as residues from the cleaning of concrete mixers in pre-mixed plants which produce pavements, foundry slags, mortars and/or concrete. Likewise, it relates to the formulation of said aggregates and to construction products obtained through them.

Claims

1. A procedure for obtaining aggregates from construction and demolition waste, wherein the procedure comprises the following steps: a. collecting construction and demolition waste; b. separating one or more materials that do not enter a recycling process, these materials can be metals, pieces of construction rods, paper, cardboard, expanded polystyrene (EPS), broken glass, wood and all solid waste unrelated to the construction activity; c. transporting the remains of concrete, stone, gravel, mortars and clay materials to the crusher for their subsequent crushing; d. sifting out the crushed material, through a vibrating or rotating screen, equipment that consists of several overlapping meshes that separate the recycled aggregates into different particle sizes; where the resulting recycled aggregates are: fine recycled aggregate (0-2.5 millimeters), coarse recycled aggregate (2.5-5 millimeters) and confectionery (5-9 millimeters); aggregates with a particle size greater than 9 millimeters will re-enter the crushing process (Step c). e. making a mix having 24% or 30% at least of fine recycled aggregate; 35% or 44% of coarse recycled aggregate; 13%, 16% or 21% of binder; and 2%, 5% or 13% of water; f. carrying the mix up to a vibro-compactor machine having a mold; and, g. curing and drying the product obtained in step f.

2. A concrete paver made up of recycled aggregates obtained by the method detailed in claim 1, which is composed of the following semi-dry mix formulation: 30% of fine recycled aggregate, 44% of coarse recycled aggregate, 13% of binder, which can be the Portland-type cement or the ecological cement made with industrial waste, and 13% of water; which for installation of the pavers requires that the bed layer under the pavers have recycled coarse aggregate and the sealing layer above the pavers have recycled fine aggregate.

3. An 18-hole King Kong-type brick made up of recycled aggregates obtained by the method detailed in claim 1, which is composed of the following semi-dry mix formulation: 30% of fine recycled aggregate, 44% of coarse recycled aggregate, 21% of binder, which can be Portland cement or ecological cement made with industrial waste, and 5% of water.

4. A concrete block made up of recycled aggregates obtained by the procedure detailed in claim 1, which is composed of the following semi-dry mix formulation: 24% of fine recycled aggregate, 35% of coarse recycled aggregate, 23% of confectionery, 16% of binder, which can be Portland cement or ecological cement made with industrial waste, and 2% of water.

Description

BRIEF DESCRIPTION OF THE FIGURE

[0014] FIG. 1: Flow diagram showing the steps of the process for obtaining aggregates from construction and demolition waste.

DESCRIPTION OF THE INVENTION

[0015] This proposed invention consists in the development of a process for the manufacture of construction products of various types, which will replace the use of conventional aggregates, as the main raw material, with the use of recycled aggregates, this being possible by the processing of construction waste. The recycled aggregates thus obtained and the final manufactured products with said aggregates will also be protected.

[0016] A critical issue in this invention, considering it as a solution to the technical problem posed herein, is to obtain the right aggregate particle size applying the proposed method in the processing of construction and demolition waste. The particle size will be determined by the type of product to be manufactured, the minimum cavity of the mold and the pattern of particles thrown out by the crusher.

[0017] The proposed process herein starts with the collection and segregation of construction waste in a way that, after applying a crushing and sieving process, they are reused to produce construction products.

[0018] As a first step, waste is obtained from construction works, renovation or remodeling works, and from demolition of infrastructures. Then a segregation process of the materials that do not enter the recycling process is carried out, these materials can be metals, construction rods, paper, cardboard, expanded polystyrene (EPS), broken glass, wood and all solid waste not related to the construction activity. In the next step, such remains of concrete, stone, gravel, mortars and clay materials are transported to the crusher for their subsequent crushing process.

[0019] Once the construction and demolition wastes are crushed, after going through a task of selection and cleaning, they are sieved in order to obtain the particles of the required size for the type of product to be fabricated. The sieving process is carried out through the use of a vibrating or rotating screen, equipment that has several overlapping meshes that will separate the recycled aggregates into different particle sizes.

[0020] The screen is designed to have four levels of separation, the base of each level being a mesh that will differ from the meshes of the other levels by their size, so that the upper mesh is the first mesh, and the lower mesh is the fourth mesh. The fourth mesh will segregate the finest recycled aggregates, which must have particle sizes ranging from 0 to 2.5 millimeters, these aggregates are collectively referred to as fine recycled aggregates. The third mesh will segregate aggregates that have particle sizes ranging from 2.5 to 5 millimeters, which together are called coarse recycled aggregates. The second mesh will segregate aggregates that have particle sizes ranging from 5 to 9 millimeters, which together are called confectionery. Finally, the first mesh will segregate aggregates that have particle sizes ranging above 9 millimeters, which will be returned to the crusher in order to reduce their size.

[0021] For further knowledge, the detailed process for obtaining recycled aggregates based on construction and demolition waste that is to be protected herein consists of the following stages: [0022] 1. Segregating and choosing of construction and demolition waste. In this stage, the metallic and ferrous elements, broken glass, paper, cardboard, plastic, expanded polystyrene (EPS) and all solid waste, not related to the construction activity, will be separated. The elements that will enter the crushing process are concrete remains, stone materials, mortars, clay materials and the like. [0023] 2. Crushing the selected elements mentioned in Step 1 with a conventional crusher. [0024] 3. Sieving or shaking of the selected and crushed waste. At this stage, the final recycled aggregates are produced, which are of 3 types: fine recycled aggregate, coarse recycled aggregate and confectionery, depending on the particle size obtained: from 0 to 2.5 millimeters for fine recycled aggregates, from 2.5 to 5 millimeters for coarse recycled aggregates and from 5 to 9 mm for confectionery. Crushed waste with a particle size greater than 9 millimeters will be sent back to step 2.

[0025] The recycled aggregates thus obtained will be ready to be sold as construction aggregates or to be mixed with other inputs in the manufacture of pre-fabricated materials such as concrete pavers, bricks, concrete blocks, tiles and the like. The recycled aggregates can also be used for mixing in the elaboration of other products such as concrete (crushed stone, coarse recycled aggregate and cement), mortar (coarse recycled aggregate and cement) and plastering (fine recycled aggregate and cement).

[0026] The following production process is carried out to manufacture the product concrete paver: [0027] 1. By means of a horizontal-axis mixing machine or one of a pan type, a mixture is made which has 30% of fine recycled aggregate, 44% of coarse recycled aggregate, 13% of binder, which can be Portland cement or manufactured ecological cement with industrial residues, and 13% of water, mixing it until it becomes a semi-dry mixture. [0028] 2. Taking the mixture to a vibro-compactor machine which has a concrete paving stone mold. The concrete pavers to be so manufactured must meet the requirements of the Peruvian Technical Regulations (NTP, as per its acronym in Spanish) 399.611 or equivalent standard; they will be rectangular in shape and should be 20 centimeters long and 10 centimeters wide. Their height will depend on the type of concrete paver to be manufactured, since they can be a pedestrian type with a height of 4 centimeters, a light vehicle type with a height of 6 centimeters and a heavy vehicle type with a height of 8 centimeters. [0029] 3. Once the mixture has been vibrated and compacted, the concrete pavers will be removed from the machine. [0030] 4. The concrete pavers go through a curing process, in which, for a period of three days, they will have constant contact with water, either by submerging them in a pool of water or by being sprinkled on. [0031] 5. After the curing process, the concrete pavers will be dried for a period of 20 days in a cool and covered place, with no direct contact with sunlight.

[0032] The following production process is carried out for manufacturing the King Kong 18-hole brick product:

[0033] 1. By means of a horizontal-axis mixing machine or one of a pan type, a mixture is made that has 30% of fine recycled aggregate, 44% of coarse recycled aggregate, 21% of binder, which can be Portland cement or manufactured ecological cement with industrial residues, and 5% of water, mixing it until it becomes a semi-dry mixture. [0034] 2. Taking the mixture to a vibro-compactor machine that contains a King Kong brick mold. The bricks to be so manufactured must meet the requirements of Technical Regulation E.070 for bricks for structural purposes of class IV or equivalent standard. The manufacturing mold must produce bricks 9 centimeters high, 23 centimeters long and 13 centimeters wide. [0035] 3. Once the mix has been vibrated and compacted, the bricks will be removed from the machine. [0036] 4. The bricks will go through a curing process, in which, for a period of three days, they will have constant contact with water, either by submerging them in a pool of water or by being sprinkled on. [0037] 5. Once the curing process is done, the bricks will be dried for a period of 20 days in a cool and covered place, with no direct contact with sunlight.

[0038] The following production process is carried out for manufacturing the concrete block product: [0039] 1. By means of a horizontal mixing machine or one of a pan type, a mixture is made that has 24% of fine recycled aggregate, 35% of coarse recycled aggregate, 23% of confectionery, 16% of binder, which can be type cement Portland or ecological cement made with industrial waste, and 2% of water, until obtaining a semi-dry mix. [0040] 2. Taking the mixture to a vibro-compactor machine containing a block mold. The blocks to be so manufactured must meet the requirements of the Peruvian Technical Regulation (NTP, as per its acronym in Spanish) 399.602 or equivalent standard. The blocks will be rectangular in shape and should be 39 centimeters long and 19 centimeters wide. The height can be varying of 9, 12, 14 and 39 centimeters. [0041] 3. Once the mixture has been vibrated and compacted, the blocks will be removed from the machine. [0042] 4. The blocks will go through a curing process, where, for a period of three days, they will have constant contact with water, either by submerging them in a pool of water or by being sprinkled on. [0043] 5. After the curing process, the blocks will be dried for a period of 20 days in a cool and covered place, with no direct contact with sunlight.

[0044] The features and multiple possibilities of the recycled aggregates which are assembled by means of this described process herein, allow the development of different construction products aside from the well-known bricks, concrete blocks, concrete pavers and tiles; consequently, the present description is not intended to limit the many possibilities and alternatives for using these recycled aggregates. Any expert in the technical field can infer many new products by using the techniques and processes made known herein in base of the raw materials (aggregates) described here.

[0045] The advantages offered by the aggregates obtained through this process are quite impressive since, primarily, they are a mixture of excellent quality, besides using a minimum percentage of waterbeing a dry mixture, also having a market price equal to or less than the conventional aggregates, and with the very important benefit of being an eco-friendly and sustainable product.

[0046] Other advantages offered by these products compared to conventional aggregates are: [0047] Cost savings: The purchase of pre-manufactured materials (bricks, pavers, blocks, etc.) and the aggregates for their installation (recycled aggregates) as a whole have a lower price when compared to purchasing pre-manufactured materials and aggregates for their conventional installation, adding to this the logistical cost. For example, for a user to install 1 m2 of conventional concrete pavers (manufactured with natural resource aggregates), they must purchase an average of 50 units of paving stones, 0.05 m3 of conventional coarse aggregate for the bed layer and 0.0075 m3 of conventional fine aggregate for the sealing layer. Instead, this same user can collectively purchase the same number of pavers made from recycled aggregates and the same number of fine and coarse recycled aggregates, at a lower price than conventional ones. [0048] Does not contain salts [0049] Waste is minimal [0050] The brick does not have deformations, since it does not go through a heating process compared to clay brick [0051] A brick wall made from recycled aggregates requires less amount of plastering material than a clay brick wall.