METHOD FOR PRODUCTION OF A MODIFIED CEMENT POWDER AND A METHOD FOR SOIL IMPROVEMENT WITH THE MODIFIED CEMENT POWDER

Abstract

A method for production of a modified cement powder comprises the steps of: a) acquiring batch cement, and b) forming a modified cement powder with an average particle size of between 2 nm and 150 nm. A method for improving the stability of a soil sample comprises a steps of: a) acquiring the soil sample, b) acquiring a cement, c) forming a cement powder (nano-cement) with an average particle size of between 2 nm and 150 nm, optionally preparing a suspension of the nano-cement in water, d) mixing the cement powder or the suspension of the cement powder in water with the soil sample in a weight ratio of between 1:100 and 1:1 of the cement powder to the soil sample, respectively, e) applying the mixture obtained in step d) to the required construction site, optionally by applying the PWS mixtureing, f) forming the mixture at the construction site in accordance with a predetermined construction project until a structure of predetermined dimensions is obtained, g) exposing the structure obtained in step f) to an amount of water for the curing time.

Claims

1. A method for production of a modified cement powder, comprising the steps of: a) acquiring a batch cement, b) forming the modified cement powder with an average particle size of between 2 nm and 150 nm, wherein forming the modified cement powder is performed by grinding the batch cement in a rotating ball mill, wherein the ball mill includes a plurality of mill balls, wherein the average particle size of the modified cement powder produced is between 2 nm and 100 nm.

2. A method for improving the stability of a soil sample, the method comprising steps of: a) acquiring the soil sample, b) acquiring a batch cement, c) forming a modified cement powder with an average particle size of between 2 nm and 150 nm, d) mixing the modified cement powder with the soil sample in a weight ratio of between 1:100 and 1:1 of the modified cement powder to the soil sample, respectively, e) applying the mixture obtained in step d) to the required construction site, f) forming the mixture at the construction site in accordance with a predetermined construction project until a structure of predetermined dimensions is obtained, g) exposing the structure obtained in step f) to an amount of water for the curing time.

3. The method of claim 2, wherein the step c) of forming the modified cement powder is performed by grinding the batch cement in a rotating ball mill, wherein the ball mill includes a plurality of mill balls, wherein the average particle size of the modified cement powder produced in step c) is between 2 nm and 100 nm.

4. The method of claim 3, wherein the weight ratio of the batch cement to the plurality of the mill balls is between 1:15 and 1:30 wt/wt.

5. The method of claim 3, wherein the ball mill is configured to rotate at a rotational speed between 600 rpm and 4200 rpm.

6. The method of claim 2, wherein a weight ratio of the modified cement powder and the soil sample as ingredients for mixing in step d) is between 1:100 and 1:1 wt/wt.

7. The method of claim 2, wherein the step d) of mixing the modified cement powder and the soil sample includes mixing for a period of time from 10 minutes to 120 minutes.

8. The method of claim 2, wherein the step d) of mixing the modified cement powder and the soil sample is performed by a rotary mixer configured to rotate at a rotational speed of between 70 rpm and 120 rpm.

9. A method for improving the stability of a soil sample, the method comprising steps of: a) acquiring the soil sample, b) acquiring a batch cement, c) forming a modified cement powder with an average particle size of between 2 nm and 150 nm, d) forming an aqueous suspension of the modified cement powder, e) placing the aqueous suspension of the modified cement powder in an ultrasonic water bath for 5-30 min to disperse the modified cement powder for geochemical fractionation, f) mixing the aqueous suspension of the modified cement powder obtained in step e) with the soil sample in a weight ratio of the aqueous suspension of the cement powder to the soil sample of between 1:100 wt/wt and 18:100 wt/wt, wherein the result of step f) is a spray mixture, g) applying the spray mixture obtained in step f) to the predetermined construction site, h) allowing the structure obtained in step g) to harden for a curing time.

10. The method of claim 9, wherein the step d) of forming an aqueous suspension of the modified cement powder includes forming the aqueous suspension of the modified cement powder with a weight ratio of the modified cement powder to the water between 1:100 wt/wt and 18:100 wt/wt.

11. The method of claim 9, wherein the step d) of forming the aqueous suspension of the modified cement powder includes mixing the modified cement powder and the water in an ultrasonic homogenizer.

12. The method of claim 9, wherein the modified cement powder and the water is mixed in the ultrasonic homogenizer for the period of time between 10 minutes and 45 minutes.

13. The method of claim 9, wherein the modified cement powder suspension and the soil sample is mixed for the period of time between 1 and 15 minutes.

14. The method of claim 9, wherein the modified cement powder suspension and the soil sample is mixed in a rotary mixer with a rotational speed of between 20 rpm and 80 rpm.

15. The method of claim 9, wherein applying the spray mixture obtained in step f) to the predetermined construction site is performed with a spraying device for spraying an enclosure with the aqueous suspension of the nano-cement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] These aims together with other objects and advantages which will become subsequently apparent reside in the details of the construction and operation as more fully hereinafter described and claimed, reference being made to the accompanying drawings forming a part hereof, wherein the same numerals refer to the same parts throughout.

[0029] In drawings

[0030] FIG. 1A illustrates schematically the work principle of the ball mill for the nano-cement production,

[0031] FIG. 1B illustrates schematically the work principle of another embodiment of the ball mill,

[0032] FIG. 2A illustrates a DLS analysis for the nano-cement regarding intensity,

[0033] FIG. 2B illustrates a DLS analysis for the nano-cement regarding volume,

[0034] FIG. 2C illustrates a DLS analysis for the nano-cement regarding number,

[0035] FIG. 3A illustrates a XRD diagram before the nano-cement production process, consistent with one or more exemplary embodiments of the present disclosure,

[0036] FIG. 3B illustrates a XRD diagram after the nano-cement production process, consistent with one or more exemplary embodiments of the present disclosure,

[0037] FIG. 4 illustrates a Zeta analysis for the nano-cement,

[0038] FIG. 5 illustrates an Scanning Electron Microscope (SEM) image of the nano-cement particles.

DETAILED DESCRIPTION OF INVENTION AND PREFERRED EMBODIMENT

[0039] Referring to the drawing, FIG. 1A shows schematically a principle of operation of a ball mill (not claimed). The ball mills are well known, therefore the construction will be not described here in details. However, operating parameters of the ball mill, for example the size and material of the balls, the weight ratio of the balls to the batch cement, rotational speed of the ball mill cylinder, inclination of the rotational axis, time of operating, etc, are changeable and are to be set according to the requirements of the output material (the nano-cement). It can be seen on FIG. 1A that during operation, the ball mill cylinder rotates according to the direction of the arrow A. The crushing medium G, which includes a plurality of metal balls of sizes 1 cm, 1.5 cm and 2 cm, rotate inside the cylinder around an axis. The bottom plate of the device and the cylinders containing the material to be grinded and/or crushed and/or shredded which is the cement powder (batch cement, M) rotate around an axis perpendicular to each other in opposite directions (one clockwise and the other counterclockwise). These movements are creating a centrifugal force. The balls first are pressed to a wall of the cylinder due to the centrifugal force caused by the rotational motion of the chamber and then the centrifugal force caused by the rotational motion of the plate dominates the force and, the balls in the cylinder are falling on the batch cement material particles in a specific position due to the gravity and are causing them to crush and ultimately convert the particles to nano size. The wording nano size or nano-cement in this description means a size from around 5 nm to around 100 nm (nanometers). In simpler terms, these methods are among the methods in which by crushing and shredding larger materials and particles into smaller particles and continuing this process to the size of nanometers, they become nanoparticles, which means a particles with the average nano size as described above. The particle size of the primary powder of the batch cement may determine the degree of purity, the shape of the material particles and the degree of quality of the material. Another construction of the ball mill (not claimed) is shown on FIG. 1B. This planetary ball mill includes a number of ball mill cylinders (grinding jars) which are rotatably placed on an independently rotatable base plate. The directions of rotation B of the grinding jars and the directions of rotation A of the base plate are opposite. The grinding balls in the grinding jars are subjected to superimposed rotational movements, the so-called Coriolis forces. The difference in speeds between the balls and grinding jars produces an interaction between the frictional and the impact forces, which releases high dynamic energies. The interplay between these forces produces the high and very effective degree of size reduction of the planetary ball mill. In one example of the invention, the weight ratio of the batch cement and the metal balls put into the ball mill cylinder can be 1:5 and 1:15, the rotational speed of the cylinder can be 300-1500 rpm, the time of the operation can be 10-60 min. FIG. 2A, FIG. 2B and FIG. 2C shows a DLS Analysis for nano-cement suspension using Pade Laplace. The first order result from a DLS experiment is presented on FIG. 2A. It is the intensity distribution of particle sizes. The intensity distribution is weighted according to the scattering intensity of each particle fraction or family. The particle scattering intensity is proportional to the square of the molecular weight. The volume distribution presented on FIG. 2B demonstrates the total volume of particles in various size bins. The intensity distribution gives the amount of light scattered by the particles in the different size bins. The DLS number on FIG. 2C mean size distribution curves of the solution. The output results for determining the cement particle size range in FIG. 2A, FIG. 2B and FIG. 2C are between 5 and 100 nm. XRD tests have been performed to ensure that the output cement did not become contaminated by the wear of metal and ceramic balls during the nano production process. FIG. 3A and FIG. 3B shows the results of the XRD experiments. The nano-cement particles, respectively, are after the production process. The results of the XRD test are presented before and after the procedure. The X-ray diffraction (XRD) is a versatile non-destructive analytical technique used to analyze physical properties such as phase composition, crystal structure and orientation of the powder, the solid and the liquid samples. These figures show the crystallographic structure of the cement.

[0040] The results of the XRD test after the process are as follows: According to the presented results, the peak points in the whole nano production process have been constant, which shows that no additional material in the nano production process has been added to the batch cement. Also, the results of XRD test on the sample before and after the nano-production process show that no changes have occurred in the powder components. FIG. 4 illustrates a zeta analysis for the nano-cement. The magnitude of the zeta potential gives an indication of the potential stability of the colloidal system. If all the particles in suspension have a large negative or positive zeta potential then they will tend to repel each other and there will be no tendency for the particles to come together. The result of the analysis indicated on FIG. 4 is that in the range from 30 to 60 mV and from ?30 to ?60 mV the zeta potential is stable, but in the range from ?30 to 30 mV the zeta potential is unstable. FIG. 5 illustrates a Scanning Electron Microscope (SEM) images of the cement particles after the process of nano-production. As shown, the measured sizes of three chosen particles are 61.87 nm, 64.05 nm and 62.09 nm, respectively.

[0041] In describing a preferred embodiment of the invention, specific terminology is resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.