WO2019151957A1

WO2019151957A1 - A formula of powder materials for machines used in forming construction, structural, and the powder materials thereof

Info

Publication number: WO2019151957A1
Application number: PCT/TH2018/000003
Authority: WO
Inventors: Lapyote PRASITTISOPIN; Kittisak PONGPAISARNSEREE; Chalermwut SNGUANYAT; Enrico Dini
Original assignee: Scg Cement-Building Materials Co., Ltd.
Priority date: 2018-01-30
Filing date: 2018-01-30
Publication date: 2019-08-08

Abstract

This invention discloses a method of constructing a layered structure comprising the steps of receiving the physical data of the object to be modeled; providing a data set of at least one predefined voxel shape; generating a geometric representation corresponding to the said physical data using the selected voxel shape; providing a chamber filled with a non-flowable material and a print head means connected with the said chamber having at least one nozzle; dispensing a plurality of drops of the non-flowable material on a periodic basis directed vertically downward to a target surface underneath in a layerwise fashion; and repeating said dispensing to form a layered structure, wherein the step of generating a plurality of drops comprises the step of configuring the position of the nozzle such that, with reference to the position of the earlier drop, the subsequent drop has a predetermined horizontal distance displacement whereby allowing voxels formed by the earlier drop and the subsequent drop be arranged in an overlapping manner; and wherein a compression between a partially formed voxel created by an earlier drop and a subsequent drop causes the sacrifice of at least some volume of voxel and fusion of the material at the points of compression thereby forming a fused zone, and wherein at least one part of said voxel is partially protected from compression thereby providing strength to the cured structure and forming a non-compressed zone.

Description

A FORMULA OF POWDER MATERIALS FOR MACHINES USED IN FORMING

CONSTRUCTION, STRUCTURAL, AND THE POWDER MATERIALS THEREOF

FIELD OF INVENTION

This invention is related to cement compositions.

BACKGROUND

At present, the forming of construction, structural, and architectural works, both indoor and outdoor, utilizes machines having automatic systems which rely more on the use of computer aided design or CAD . The use of a machine is intended to increase the speed of the operation, reduce the residuals during construction, reduce operational cost, and reduce the use of labor which is difficult to find . Therefore, the development of materials that are suitable for forming products by machines has become increasingly necessary .Because of the higher speed of operation, materials to be used need to be precisely applied to machine operations, namely such materials can cause a reaction at the period of time correlated to the operation time of machines. Most of these materials are in the form of powder.

Presently, there have been developments with regard to the application of construction materials having cement or mortar compositions in relation to the automatic machine used for 3D forming. However, it can be said that there have not been many developments in relation to the use of raw materials in the form of powder which is the important characteristic of this invention .This may be because the problems encountered during the actual operations which prevent the products from obtaining strength and durability, particularly products with strength and durability obtained without a curing process .

When mixing construction materials having the compositions of cement or mortar with water for use with the machine, it is required to have a proper calculation in relation to the reaction time for curing and product qualities, particularly, the compressive strength along with the other required durability characteristics .

Machines used for 3D shaping constructions, structures, and architectural works, both indoor and outdoor, at present, utilize two approaches which are related to this invention .The first approach is to scatter powder materials until a thin layer is obtained .Thereafter, such layer will be sprayed with liquid or water drops so that the powder materials can be solidified .This procedure will be repeated until the desired workpiece is obtained .The second approach is to scatter powder materials and crush or shake such materials in order to arrange the particles of the powder materials .Thereafter, it will be sprayed with liquid or water drops continuously layer by layer .The operation according to this approach is similar to Roller Compacted Concrete or RCC technology which is a crushed concrete technology .However, RCC technology requires the prior mix of cement, mass aggregates and water using the mixing machine .Such mixture is called semi wet mixture so that cement, mass aggregates, and water can have sufficient dispersion and contacts and can react well with each composition thereby obtaining strong products . In general, the principle of such mix is to have the suitable level of moisture in the mixture which leads to good adhesion and obtains the mixture of wet concrete that has the slump of zero according to the test based on ASTM C143 )Standard Test Method for Slump of Hydraulic-Cement Concrete .(Such mixture which is a semi wet homogenous mixture will then be sprayed or layered or poured at the work area and crushed, compressed, or shaken with heavy machines. Concrete with strength durability and higher compressive strength can then be obtained. Examples of construction utilizing RCC technology include reservoir and road construction.

This invention adopts the approach of RCC technology .However, the use according to this invention is the use of powder materials which are dried, crushed and formed into different layers and later sprayed with water or liquid having water and the main composition .

The inventions in the same category which covered the developments of dried mortar substance and/or bonding agent in the form of powder and liquid having similar characteristics to this invention are

The invention according to the application No .TH 1501006532 dated October 26, 2015 disclosed the technology in forming workpieces for general use using construction material texture in the form of powder which has powder cements as the main composition and has a hydraulic type bonding agent for increasing strength . The machine is operated by scattering the powder materials and sprayed the same with water without the process of crashing or shaking .The products obtained from this process have insufficient strength for use and require at least another 2 steps of curing process .The first curing process needs the curing time of at least 1 hour at high temperature in the range of 60 to 200 degrees Celsius .The second curing process uses sulfate or alkaline solution as a composition thereby obtaining products with the strength between 40 to 88.5 kg /cm2. This disclosure is different from this invention as it does not contain the crushing procedure and products obtained from this prior disclosure still require a curing process.

For the other related inventions that use machines for forming 3D constructions, powder materials are used. However, they are not cement or bonding agents in the category of hydraulic. Said inventions include:

The U.S. invention according to US 2008/0148683 A1 (Method and Device for Building Automatically Conglomerate) describes the method of use of the machine for scattering powder materials. The powder materials used are the substance that do not cause a reaction or inert materials. Said materials are sprayed with solvent in the form of liquid and have polymer resin in the category of cross linking epoxy polyurethane as a bonding agent. The machine having an automatic system is used for 3D constructions. This is different from this invention in the aspect of powder materials and liquid as a solvent and also the lack of crushing process.

The U.S. invention according to US 2010/0207388 A1 (Method for Automatically

Producing a Conglomerate Structure and Apparatus Thereof) is the invention related to the scattering of powder material and have the same crushed or shaken before spaying with liquid. This is to develop a method for forming large structures or workpieces with a suitable strength sufficient for works. This utilizes materials as bonding agents which are liquid part and catalyst in the category of chloride in order to improve the strength of the products. This is different from the invention in which the powder materials are required to react with liquid part and catalyst in the category of chloride only and the products obtained are not resistant to outdoor environments or in states with high moisture.

The invention according to WO 2011021080 A2 (Method and Apparatus for Quick

Production of a Conglomerate Building Structure) is the invention related to the scattering of powder materials and have the same cursed or shaken before spraying with liquid. This is for forming a workpiece into a building structure. The powder materials used comprise metal oxide compositions as a principle component such as magnesium oxide, silicon oxide, iron oxide, calcium oxide, aluminum oxide, and liquid being a high concentrated solvent of magnesium chloride as an reagent. The said product is not resistant to outdoor use. This is because, when the product is touched or comes in contact with water, the product will expand and crack due to the chemical reaction of the said compositions. This is different from this invention in which the cement materials are used as a bonding agent to strengthen and enhance the water resistance thereby preventing fractures and allowing outdoor use and also being appropriate for constructions and structural works.

Therefore, it can be seen that, in this invention, powder materials comprising principle components of Portland cements, white cements, calcium aluminate cements, or the mixture of the compositions thereof together with mass aggregates are used for forming products with the technology in scattering materials and crushing or shaking the same before spraying with liquid or water or liquid having water as a main composition for causing a reaction. Products with strength can be obtained without a curing process and are resistant to water and outdoor environments.

SUMMARY OF THE INVENTION

The objective of this invention is to develop powder materials for construction that can be used with a machine having an automatic system. Such machines are used for forming constructions or workpieces in 3D by scattering materials and having the same crushed or shaken in order to have the particles suitably arranged and have particle packing between 85 to 95 percent before spraying the same with liquid. The powder materials which are bonding agents will have a relationship with the amount of water. The amount of water to powder materials is in the range of 3 to 15 percent by weight. Such powder materials comprise the principle materials of Portland cements, white cements, calcium aluminate cements, or the mixture of the compositions thereof and liquid comprising water or liquid principal comprising water as a reagent. The products having

compressive strength at 7 days of not less than 150 kg./cm2 can then be obtained without a curing process.

This invention is a solution to the problem in forming construction workpieces in which strength is required after mixing with water. The required products can be obtained without a curing process and resistant when coming in contact with water and also resistant to outdoor environments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the behaviors of particle packing that affect the forming of the products.

FIG. 2 shows the graph of compressive strength of the products at 7 days in relation to f P) FIG. 3 shows the graph of compressive strength at 7 days in relation to particle packing FIG. 4 shows the samples of the products.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

To manufacture construction material products, powder materials are used with a machine having an automatic system. For forming constructions, an apparatus is used for scattering powder material into thin layers. Such layers are later sprayed with the liquid drops in order to solidify the materials. This process is repeated until the desired workpiece is obtained. This is the technology in the field of 3D architectural construction. This invention selects powder materials to be used as a bonding agent in which the principle materials comprise Portland cements, white cements, calcium aluminate cements, or the mixture of the compositions thereof having the appropriate average particle size. The materials are scattered into layers and crushed at the same time in order to have suitable arrangements of materials. Thereafter, water or liquid.principally containing water were sprayed. Water will suitably penetrate through the particles of powder materials in each layer and cause appropriate reactions thereby preventing an excess over the surface or an excess which flows to the previous layers of powder materials positioned in the lower level. This means that the powder materials in each layer can optimally react with the amount of water thereby strengthening the products layer by layer. The consequence of this process is to obtain products with strength that do not require a curing process.

When planning the compositions of powder material to be suitably applied with liquid and cause the reaction combination thereby obtaining the desired properties, it is important to calculate the appropriate size of particles so that there is a cavity for the liquid or water to optimally penetrate. The inventor found that the behavior of the particles of compressed powder material after being crushed by machine or called as particle packing (figure 1) has a correlation with the amount of water sprinkled or sprayed from the nozzle. Therefore, the inventor developed the formula for the calculation of the density of powder material in relation to an amount of water called as f(P).

The experiment to find f(P)

For the calculation of the relationship between the amount of water and powder materials which is optimal for the reaction, this invention uses the value called f(P). This can be calculated as a percentage from the density of dry powder, liquid spraying period, liquid spraying rate, height of each layer, and area of laying mortar according to the following formula 100

The said formula was used for testing the compressive strength of the product to f(P). It was found that, according to the testing results in the table 1, the adjustment of f(P) led to different compressive strengths. After the amount of water was increased from 3.15 to 12.5 %, the compressive strength at 7 days also increased from 42 kg. / cm2 to the maximum value of 274 kg./ cm2. This shows that the increase in the water amount was sufficient for bonding powder materials in each layer and reached the optimal point when f(P) was 12.5%. However, when increased more than 15%, the compressive strength at 7 days decreased. This was due to excessive water which reduced the compressive strength. Therefore, the optimal range of f(P) is found to be in the range of 3 to 20% and the best optimal range according to this invention is 8 to 15%.

The experiment to find particle packing

In finding the relationship between the amounts of water and powder materials, the other important factor is the particle size of powder materials. The inventors studied the behavior of particles according to sizes of particles of powder materials and calculated the particle packing from linear particle packing modeling (De Larrad 1999) as per the following

Particle packin

In this invention, it was found that (table 2) the value of particle packing calculated from the above formula is in the range of 85 to 95%. This range caused the particles of powder materials to be arranged in an appropriate manner. After being sprayed with water, construction materials with the strength at 7 days of more than 150 kg./ cm2 can be obtained. In this regard, the sizes of the particles used in the powder materials were varied. These included the use of Portland cements, white cements, calcium aluminate cements, or the mixture of the compositions thereof and mass aggregates such as coarse crushed rocks or sands (Al), river sands (A2), or fine crushed rocks (A3).

Hence, it was found that, for the relationship between the amounts of water and powder materials, the appropriate value is in the range of 3 to 15 percent and the appropriate size and amount of powder materials calculated as particle packing is in the range of 85 to 95 percent. These were then used for developing formulas of powder materials suitable for use.

The experiment in relation to the development of the formulas of powder materials

The compositions of powder materials that are used with machines having an automatic system for forming constructions are crushed/shaken in order to obtain products with desired strength. Generally, the measurement of the strength of construction materials can be considered based on the compressive strength of more than 250 kg. / cm2 at 28 days or comparable to the compressive strength of 150 kg./cm2 at 7 days hi the experiment, the powder materials principally comprise Portland cements, white cements, calcium aluminate cements, or the mixture of the compositions thereof. The scattered powder materials in each layer have a thickness between 0.5 to 2.2 cm and the average size of the particles is between 8 to 75 microns and coarse aggregates such as crushed rocks and/or sands including the property modifier such as water reducer, redispersible polymer, supplementary cement materials or SCM, strengthening substance, have the average particle size between 100 to 800 microns. The fineness modulus of the overall powder materials is between 1.95 to 2.65 which can be tested according to ASTM C33 standard.

Additionally, various types of fiber can be included in order to enhance the strength of the products provided that the average particle size is still between 100 to 800 microns. The aforesaid powder materials were mixed together as a homogeneous mixture and then scattered into layers and, at the same time, crushed or shaken so that the particles of powder materials suitably arranged. Thereafter, the materials were sprayed with liquid or water or liquid principally comprising water for the forming process.

The strength of the formed materials was measured. There are 11 formulas of the powder materials used in the experiment (Table 1) and the compressive strengths at 7 days are shown in Table 2. From the original ratio based on formula 4 of the powder materials which comprises Portland cements, white cements, calcium aluminate cements, or the mixture of the compositions thereof and coarse aggregates having the compressive strength at 7 days of 186 kg./cm2, the amount of cement, mass aggregates were adjusted and various property modifiers were added. In formula 1 to 3 and 5 to 11, it was found that the formula that provides the highest compressive strength of 634 kg./cm2 was formula 11 due to the use of the strengthening substance in the category of silicate in the powder materials together with water reducers. Table 1 formula samples of powder material products

Table 2 compressive strength at 7 days of powder materials

In the experiments of manufacturing the products, the inventor used the suitable formula of powder materials, namely formula No. 10. The materials were mixed in the large mixing apparatus for an appropriate period of time thereby obtaining homogeneous mixture. The total amount of compositions was 2000 kg. The same were then applied with the construction forming apparatus and scattered into layers having the thickness between 0.5 to 2.2. cm. and crashed at the same time in order to have suitable arrangements of materials. Thereafter, water or liquid principally containing water were sprayed with f(P) of 12.5 percent. Water will suitably penetrate through the particles of powder materials thereby obtaining the workpiece without the need of a curing process as shown in Figure 4.

It will be appreciated by persons skilled in the art that the present inventions are not limited by what has been particularly shown described hereinabove. Rather the scope of the present invention includes both combinations and sub-combinations of the features described hereinabove as well as modifications and variations thereof which would occur to a person of skill in the art upon reading the foregoing description and which are not in the prior art.

Claims

1. A formula of powder materials for indoor and outdoor construction, structural, and

architectural works which can be used with machines having an automatic system for forming constructions, workpieces by scattering powder materials and crushed or shaken such powder materials in order to have suitable arrangements and particle sizes of materials wherein the value of particle packing is between 85 to 95 percent before spraying with the liquid and wherein said powder materials, when reacted with liquid or water act as a bonding agent and have the relationship between the amount of water to powder materials or f(P) in the range of 3 to 15 percent by weight thereby obtaining the products having the compressive strength at 7 days not less than 150 kg./cm2 without the need of a curing process and

wherein the relationship between the amount of water to powder materials or f(P) is derived from the calculation of the following equation

100

By p = density of dry powder,

T= liquid spraying period

R = liquid spraying rate

H = Height of each layer

A = Area of laying mortar

2. A formula of powder materials for constructions according to claim 1 wherein the main compositions of powder materials comprise Portland cements, white cements, calcium aluminate cements, or the mixture of the compositions thereof having the average particle size between 8 to 75 microns.

3. A formula of powder materials for constructions according to any of the claims 1 -2 wherein the mass aggregates such as crushed rocks and/or sands are added and include the property modifiers such as any of water reducers, re-dispersible polymer, supplementary cement materials, strengthening substance or the combination thereof having the average particle size between 100 to 800 micron.

4. A formula of powder materials for construction according to any of the claims 1 -3 wherein the liquid contains water as a main composition or has water as a substance causing reaction.

5. Products utilized the formula of powder material according to any of claims 14 wherein the texture of powder materials derived from the mixing of cements and coarse aggregates during the forming is a homogeneous mixture.