System and method for controlling concrete production

• US 6,227,039 B1
• Filed: 05/03/1999
• Issued: 05/08/2001
• Est. Priority Date: 01/06/1998
• Status: Expired due to Fees

• Current Assignee: Te'Eni, Moshe
• Original Assignee: Te'Eni, Moshe
• Inventors: Te'eni, Moshe
• Primary Examiner(s): Williams, Hezron
• Assistant Examiner(s): WIGGINS, JOHN DAVID
• Application Number:
  US09/303,565
• Time in Patent Office: 736 Days
• Field of Search: 73/54.03, 73/53.04, 73/54.23, 73/54.37, 73/54.39
• US Class Current: 73/54.03
• CPC Class Codes: B28B 17/0072 Product control or inspection
• CPC Class Codes: B28C 7/024 by measuring properties of the mixture, e.g. moisture, electrical resistivity, density
• CPC Class Codes: C04B 40/0032 Controlling the process of mixing, e.g. adding ingredients in a quantity depending on a measured or desired value B28C7/00 takes precedence
• CPC Class Codes: G01N 11/16 by measuring damping effect upon oscillatory body
• CPC Class Codes: G01N 33/383 Concrete, cement

Abstract

A measuring system for measuring rheological properties of a concrete mix tested when contained, the system comprising, a surface in contact with part of a mass of said concrete mix; a shearing unit for effecting shear deformation in said mass, along the direction of a shearing plane crossing through said concrete mass; and at least one sensor which senses a measure of the force which is transferred to said surface by said concrete mass as a result of said shear deformation under at least two measurement environments defining at least two different stress states, where said two measurement environments are created by said shearing unit effecting a shear deformation and where said two different measurement environments are characterized by having substantially different forces perpendicular to the shear plane of said shear deformation.

Claims

1. A measuring system for measuring rheological properties of a concrete mix tested when contained, the system comprising:

a shearing unit having a shearing unit contact surface for effecting shear deformation in a volume of said mix; and

at least one sensor which senses a measure of a force which is transferred to said concrete mix as a result of said shear deformation under at least two measurement environments, said environments defining at least two different stress states, wherein said two measurement environments are created by said shearing unit and wherein said two different measurement environments have substantially different levels of stresses acting in a direction perpendicular to shear planes formed in said mix by said shear deformation.

2. A measuring system according to claim 1 and additionally comprising a vibrator.

3. A measuring system according to claim 1 and additionally comprising a processor which receives measurements from said at least one sensor and generates, from the measurements relating to said at least two measurement environments, at least one variable relating to the workability of said concrete mix and at least one additional variable produced from the ratio of two of said at least two measurements.

4. A measuring system according to claim 1 and wherein said shearing unit is any one or a combination of the following means:

a mechanical mixer, a paddle mixer, a mechanical screw, a plunger, a hydraulic pump, a propeller and a rotatable drum.

5. A measuring system according to claim 1 and wherein said at least one sensor is any one or a combination of the following sensors:

an accelerometer, a pressure transducer, a load transducer and an electronic ruler.

6. A measuring system according to claim 1 and wherein said at least one sensor is mounted on said surface and senses a measure of a force vector in a direction generally normal to shearing planes within a measurement environment of said at least one sensor.

7. A measuring system according to claim 1 and wherein said at least one sensor is at least two sensors located on two non-parallel planes of said surface.

8. A measuring system according to claim 1 and wherein said at least one sensor is at least two sensors located in two different measurement environments along said surface.

9. A system according to claim 1, comprising a surface in contact with part of said mix.

10. A system according to claim 1, wherein at least a first sensor of said at least one sensor is mounted on said shearing unit.

18. A measuring system according to claim 4 and wherein said surface is an element of any one or a combination of the following containers:

a pipe, a box, a drum, a block forming frame and an element of a surface of said shearing unit.

11. A method for generating a rheological profile of a given concrete mix, the method comprising:

effecting shear deformation in a mass of said concrete mix;

sensing at least two measures of at least one physical parameter relating to the resistance of said concrete mass to said shear deformation;

generating from at least one of said at least two measures, at least one variable relating to the workability of said concrete mix;

generating at least one additional variable from a mathematical function of at least two of said at least two measures; and

creating said rheological profile from said variables.

12. A method according to claim 11, wherein said two measures are determined in two measurement environments which are characterized by having substantially different levels of stresses acting in a direction perpendicular to shear planes formed in said mass by said shear deformation.

13. A method according to claim 12 and wherein sensing occurs simultaneously at at least two different location points in the concrete mass.

14. A method according to claim 12 and wherein sensing occurs at a single location in said concrete mass under at least two deformational regimes.

15. A method according to claim 12 and wherein sensing occurs at least once while said mass is under vibration.

16. A method according to claim 12 and wherein said measure of said force is any of the following variables;

velocity, voltage, flow rate, acceleration, pressure and force.

17. A method according to claim 12 and wherein sensing senses a measure of a force vector normal to shearing planes within a measurement environment of a sensor.

19. A method for the control of production and the design and adjustment of concrete mixes to have desired rheological properties, the method comprising:

preparing a concrete mix in a concrete plant in accordance with a mix design indicating the proportions of solid components and water content of the concrete;

testing said prepared concrete mix with a concrete tester;

generating a rheological profile of said concrete mix from output of said step of testing;

comparing said generated rheological profile with a desired rheological profile defining desired properties of the concrete to be produced by said plant; and

adjusting said proportions of said solid components of said mix design in order to produce concrete having a rheological profile which is compatible with said desired rheological profile.

20. A method according to claim 19 and wherein preparing, testing and generating are repeated for at least three concrete mixes, at least two of which have different proportions of solid components and at least two of which have different water to solid ratios.

21. A method according to claim 19 and wherein said desired rheological profile comprises a set of rheological properties each of which has a range of allowable values.

22. A method according to claim 19, wherein testing is conducted while at least part of the concrete mix flows through a testing apparatus.

23. A method according to claim 19, wherein said rheological profile comprises:

at least one measure of the resistance to deformation of a mix under a given deformation; and

at least one quantitative indicator of a sensitivity of the resistance to deformation of said mix to stresses acting in said mix in a direction perpendicular to shear planes formed in said mix under a deformation.

24. A system which designs, adjusts and produces concrete to have desired rheological properties during times of concrete preparation and production, the system comprising:

a plant for preparing a concrete mix in accordance with a mix design indicating the proportions of the solid components and water of the concrete;

a concrete profile measuring unit for measuring a rheological profile of the concrete produced by said plant; and

a mix changing unit for receiving said measured rheological profile and a desired rheological profile “

defining desired properties of the concrete produced by said plant”

, and for indicating to said plant to adjust said solid components of said concrete mix, as many times as necessary, in order to produce concrete which has a rheological profile which is compatible with said desired rheological profile.

25. A system according to claim 24 and wherein said mix changing unit comprises a search unit for receiving a quality of change criterion and for determining the mix design change which will provide concrete having said rheological profile which is compatible with said desired rheological profile and which fits within said quality of change criterion.

26. A system according to claim 24 and wherein said concrete profile measuring unit is located away from said plant.

27. A system according to claim 24 and wherein said concrete profile measuring unit is located within said plant.

28. A system according to claim 24 and wherein said concrete profile measuring unit comprises a measuring system for measuring rheological properties of a concrete mix tested when contained, the system comprising:

a surface in contact with a part of a mass of said concrete mix;

a shearing unit for effecting shear deformation in said mass; and

at least one sensor which senses a measure of a force which is transferred to said surface by said concrete mass as a result of said shear deformation under at least two measurement environments defining at least two different stress states.

29. A system according to claim 24 wherein said rheological profile comprises:

at least one measure of the resistance to deformation of a mix under a given deformation; and

at least one quantitative indicator of a sensitivity of the resistance to deformation of said mix to stresses acting in said mix in a direction perpendicular to shear planes formed in said mix under a deformation.

30. A system according to claim 28, wherein said two stress states are characterized by having substantially different levels of stresses acting in a direction perpendicular to shear planes formed in said mass by said shear deformation.

31. A method of establishing a rheological profile characterizing a resistance to an applied deformation of concrete mixes comprising:

applying a shear deformation to a mix having a certain composition;

establishing at least one measure of the resistance to deformation of said mix under a given deformation;

establishing at least one quantitative indicator of a sensitivity of the resistance to deformation of said mix to stresses acting in said mix in a direction perpendicular to shear planes formed in said mix under said deformation; and

associating said at least one measure of the resistance and said at least one quantitative indicator of a sensitivity to provide a rheological profile of said mix.