Title of Invention : Concrete mix design system for construction plants

Technical Field

[0001] Generally, this written application is related to civil engineering, engineering, construction and execution management, and construction technology. It specifically concerns concrete preparation for construction. More specifically, it describes a system that provides optimal concrete mix designs in construction plants.

Background Art

[0002] One proposed concrete preparation design, a machine for refining material impurity to prepare ready-mix concrete in plant, has been registered in the Iran Patent Office with patent no. 83619. Designed to purify consumable sand, this machine can improve sand quality and the final quality of resulting concrete.

[0003] Another design, a plant concrete mixer (a portable batcher), has been registered in the United States Patent and Trademark Office under patent no. US4792234. It is designed specifically for large plants and shipped on trucks. It does not provide a mix design, cannot be used in small plants due to its large size, and must be carried to large plants with trailers.

[0004] Another design registered in the Japan Patent Office with patent no. JP1998048143 is a system that employs image processing technology to examine the weak materials transferred from sources to silos on conveyor belts, preventing incorrect mixtures in concrete factories. In principle, this invention can prevent the incorrect mixture of aggregates in ready-mix concrete factories.

Although this machine is not portable and cannot be used in small plants due to its structure, it can be used in production lines of ready-mix concrete factories.

Technical Problem

[0005] Since rock materials (aggregates) determine many of the physical, chemical, and mechanical characteristics of concrete, they are also crucial to the properties, mix design, and economics of concrete. Coarse grain (gravel) and fine grain (sand) rock materials account for 60-75% of concrete volume. The boundary between gravel and sand has a sieve designation of 4 with a slot size of 4.76 mm. According to the ASTM C33/C33M and ACI E1-16 Standards, the correct continuous gradation of aggregates in concrete provides greater efficiency and easier pumping of fresh concrete. This reduces the void between aggregates and water and cement consumption, thereby strengthening concrete. Compared to poorly-graded concrete with the same compaction energy, it provides greater compaction percentage, thus increasing the (ultimate) compressive strength of concrete.

[0006] According to the ASTM C33/C33M and ACI E1-16 Standards, selecting rock materials with continuous gradation and maximum diameter of grains is an important factor in the final strength. The continuous gradation of a larger maximum diameter of sand results in fewer empty voids than the continuous gradation of a smaller maximum diameter of sand. Therefore, grains of rock materials with larger diameter require less cement mortar to fill the voids between them. For better resistance, maximum sand diameter should be smaller based on the fixed water-cement ratio, and maximum diameter of materials should be smaller than the figures obtained under the following conditions.

[0007] Given the importance of the gradation of aggregates used in concrete, for gradation and ultimately obtaining the standard gradation curve (continuous or discrete), the materials (gravel and sand) should be selected and sampled based on national regulations and transferred to the laboratory. Their gradation curve is determined based on standard testing (standard sieve analysis and measurement of residual materials) and the proper mix design is obtained by trial and error according to the standard curve proposed by ACI Standard or national regulations. Therefore, the resulting curve is between the curve proposed by the ACI Standard or national regulations.

[0008] Obtaining the gradation curve of materials and their optimal mix using conventional methods requires specific laboratory tests and, consequently, special laboratory equipment. To obtain the granulation curve and optimum mix of specific materials, they should be sampled in the plant and transferred to the laboratory where the gradation curves and mix design should be obtained. It has always been challenging to use this method to obtain the gradation curve and optimal mix. For example, in addition to the relatively expensive process of using laboratory equipment to obtain the gradation curve and optimal mix in the laboratory, transferring samples of materials to the laboratory is also costly and time-consuming, raising the final project cost. Moreover, some properties of aggregate sample, such as the moisture content, may change during transportation from plant to laboratory.

[0009] Due to these challenges, to add aggregates and make their own mix designs in plants, many engineers visually estimate the gradation and mix without the relevant tests, which may affect efficiency, resistance, durability, and other physical properties of concrete. Therefore, there is a need for a system that can obtain the gradation range of materials in a plant and present a standard mix design according to the environmental conditions and available materials.

Solution to Problem

[0010] This written application discloses a concrete mix design system with a vibration table holding a vibration tray on top. The vibration table is connected to a vibration mechanism from the bottom with a separable vibration tray. To obtain the mix percentage of multiple materials, the user pours a certain amount of each material separately on the vibration tray and places the vibration tray on the vibration table. Then, the vibration mechanism vibrates the tray to spread the material with no two aggregates landing on top of each other and aggregates landing on their largest dimension. The disclosed system’s lighting function adequately illuminates the aggregate on the vibration tray and the imaging system takes an image of the material on the vibration tray and sends it to the processor. Using state-of-the-art image processing methods, the processor counts and measures the size of aggregates of that specific material. As a primary reason for the lighting system, the removal of environmental noise provides more accurate image processing and minimizes errors that could reduce image processing accuracy. For example, to combine three types of materials to create the final aggregate, the user first pours a certain amount of the first material on the vibration tray, which is then placed on the vibration table. In the aforementioned manner, the vibration mechanism vibrates the tray to spread the first material on the tray and the processor obtains the quantity and size of aggregates in the first material. Then, the quantity and size of aggregates in the second and third materials is obtained in the same manner. Then, the processor calculates the gradation curve of the final aggregate with different mix percentages of the three materials. If a particular combination of mix percentages of the three materials presents an aggregate with a curve entirely within standard gradation limits, the display will show those percentages as optimum. This will allow the user to mix the three materials based on the displayed percentages to obtain a final aggregate that ensures the final gradation curve follows the permissible limit of standards. The disclosed concrete mix design system also includes a temperature and a humidity sensor to measure and send plant temperature and humidity to the processor. Using temperature and humidity data and data related to standards and the desired concrete, the processor presents the required percentage of each material and water and cement. According to user-defined standards and rules, the processor will ensure that the concrete based on the proposed mix design will be standard and suitable.

[0011] Figure 1A shows a 3D representation of a concrete mix design system (100) that is compatible with one or several implementations of the present invention. As shown, in an example implementation, the system (100) could include a main body (102). In an example implementation, the main body (102) could have an upper (122) and a lower chamber (124) connected by four legs (126). In an example implementation, the system (100) could also have a user-interface console (123) installed on the upper chamber (122). In an example implementation, the user-interface console (123) could have a display (125). In an example implementation, the system (100) could also have a material holding tray (103). In an example implementation, the material holding tray (103) could be configured to receive various materials. For example, the material holding tray

(103) could be configured to receive specific amounts of gravel, sand, or other materials.

[0012] In an example implementation, the system (100) could have a vibration table

(104) installed on top of the lower chamber (124). In an example implementation, the vibration table (104) could be configured to receive the material holding tray (103). In an example implementation, the user can place the material holding tray

(103) on the vibration table (104) or remove it from the vibration table (104). For example, the user can remove the material holding tray (103) from the vibration table (104), pour the material on the material holding tray (103), and put it back on the vibration table (104).

[0013] Figure 1B shows a 3D cross-section of a system (100) that is compatible with one or several implementations of the present invention. Figure 1C shows a side cross-section of a system (100) that is compatible with one or several implementations of the present invention. Figure 1 D shows an oblique crosssection of a system (100) that is compatible with one or several implementations of the present invention. As shown in Figure 1 B, Figure 1C, and Figure 1 D, in an example implementation, the system (100) could also have a vibration mechanism (105) in the lower chamber (124) under the vibration table (104). In an example implementation, the vibration mechanism (105) can be configured to vibrate the vibration table (104) and consequently the material holding tray (103) to spread the materials in the material holding tray (103) on the surface of the material holding tray (103) such that no two aggregates land on top of each other and the aggregates land on the tray surface on their largest dimension. As shown in Figures 1A, 1 B, and 1C, in an example implementation, the vibration mechanism (105) could have a first vibration motor (152) and a second vibration motor (153). In an example implementation, the first vibration motor (152) can be aligned with a first axle (1522) and contact the lower surface of the vibration table

(104). In an example implementation, the second vibration motor (153) can be aligned with a second axle (1523) and contact the lower surface of the vibration table (104) where the first axle (1522) and the second axle are perpendicular. In an example implementation, the vibration mechanism (105) could also have a first spring (1541), a second spring (1542), a third spring (1543), and a fourth spring (1544) in the lower chamber (124) and under the vibration table (104) contacting the lower surface of the vibration table (104). In an example implementation, to vibrate the vibration table (104) and consequently the material holding tray (103), each of the two vibration motors could be activated for about 5 seconds for a total of 20 seconds. In an example implementation, the motors could revolve at 5600 rpm, which could change tray height in each direction by 7 mm, thereby vibrating the vibration table (104) and consequently the material holding tray (103). In an example implementation, the active time of each motor could be determined by the estimated size of the material on the tray. For example, for fine-grained materials, each motor could operate for two seconds.

[0014] In an example implementation, the system (100) could also have a lighting system (106) positioned above the vibration table (104) and connected to the lower surface of the upper chamber (122). In an example implementation, the lighting system (106) could be configured to light the material holding tray (103) and specifically, the material poured on the material holding tray. The lighting ensures that a high-quality picture is taken of the material poured on the material holding tray (103). As a primary reason for the lighting system (106), the removal of environmental noise provides more accurate image processing and minimizes errors that could reduce image processing accuracy. In an example implementation, the lighting system (106) could have several light bulbs connected to the lower surface of the upper chamber (122). In an example implementation, the system (100) could also have an imaging system (107) positioned above the vibration table (104) and connected to the lower surface of the upper chamber (122). In an example implementation, the imaging system

(107) could be configured to capture the material poured on the material holding tray (103). In an example implementation, the imaging system (107) could include high-definition (e.g., 4K) cameras, improving image quality and providing more accurate image processing and a better output. Moreover, in an example implementation, a LIDAR module (109) could be used next to each camera. The LIDAR modules (109) could be configured to produce 3D images of the material poured onto the material holding tray (103). In an example implementation, the system (100) could also have a solar cell (135). The solar cell (135) can be configured to provide the necessary energy (electricity) for system operation (100). In an example implementation, the system (100) could also receive its energy (electricity) requirements from the grid.

[0015] In an example implementation, the system (100) could also have a processor

(108). In an example implementation, the processor (108) could communicate with the imaging system (107), the user-interface console (123), and the display (125). In an example implementation, the processor (108) could be configured to receive an image from the imaging system (107) and use the image with state-of- the-art image processing methods to obtain the size and number of aggregates in the material poured on the material holding tray (103). In an example implementation, likewise, the system (100) could obtain the quantity and size of aggregates in various materials. The processor (108) could also receive and use 3D images from LIDAR modules (109) to determine the size and quantity of aggregates in the material poured onto the material holding tray (103). This information, alongside previous ones, can improve accuracy in determining the number and size of aggregates.

[0016] For example, to mix two materials to obtain the final materials in concrete production, the aforesaid process provides the number and sizes of a sample of each material. This information is then used to obtain its gradation curve, which determines the percentage of aggregates with different sizes in that particular material. Then, the processor (108) calculates different mixes with different percentages of the two materials and obtains the granulation curve of the different mixes. That is, for all X and Y integers within 1-100 where X+Y=100, the gradation curve obtained from mixing X% of the first material and Y% of the second material and the corresponding grading curve are obtained. For example, with a hypothetical final material containing 20% of the first material and 80% of the second material, X is 20 and Y is 80. Based on the calculated grain size of each of the two materials calculated and stored in memory in the previous phase, the gradation curve for the final material comprised of 20% of the first material and 80% of the second material is obtained.

[0017] In an example implementation, the processor (108) matches each gradation curve from the previous step with a standard gradation area. Note that the standard gradation area is between a predetermined lower limit and a predetermined upper limit of the gradation curve. The predetermined lower limit and upper limit of the gradation curve can be obtained from the existing user- provided standards given to the processor (108). Figure 2A shows a standard gradation area that is compatible with one or several example implementations of this invention. As shown, the standard gradation area is the enclosed area between the lower limit curve (201) and upper limit curve (202). In this diagram, the horizontal axis shows sieve size in millimeters and the vertical axis shows the passing percentage. Moreover, the curve (203) is an example of a curve inside the standard gradation area and corresponds to materials with optimum sizes of aggregates and following the relevant standards and regulations. The average of the lower limit curve (201) and upper limit curve (202) is an average curve. Tests have shown that materials with a closer granulation curve to this average curve are more favorable. Figure 2B shows a curve of optional grading requirements for fine aggregate (e.g., sand) and coarse aggregate (e.g., gravel) in concrete obtained based on existing standards and rules.

[0018] In an example implementation, after comparison of the obtained grading curves with the standard user-provided grading area given to the processor (108), if a mix of materials produces a gradation curve in the standard gradation area, the processor (108) issues commands to the display to show the corresponding X and Y (125). The display (125) shows the corresponding X and Y to the user to ensure that mixing X% of the first material with Y% of the second material will produce the final material with the standard gradation area, resulting in material with optimum gradation according to existing standards. This system can be used for any number of materials. As mentioned earlier, the closer the material’s gradation curve to the average curve of the lower limit (201) and the upper limit (202), the better the material. Therefore, after calculating the average curve, two new upper and lower limit curves can be defined for the processor (108) to place the average curve between the two new upper and lower limit curves such that the average curve’s distance from these two curves is lower than the average curve’s distance from the lower limit (201) and upper limit (202). After ensuring that the gradation curve of the material is between the new upper limit and lower limit curve, a material with a gradation curve closer to the average curve will be obtained, resulting in materials with better gradation. To apply the same method for producing the final material from mixing more than two materials, the percentages of each material can be obtained to produce a final material with a good and standard gradation curve. In an example implementation, the system (100) could also include a temperature sensor (131), a humidity sensor (132), and a GPS sensor (133). The temperature sensor (131) and humidity sensor (132) can respectively measure the temperature and humidity of the place where the system (100) is used (e.g., the plant where the system (100) is used) and send the related data to the processor (108). Moreover, the GPS sensor (GPS) (133) can locate the system (100) and send the relevant data to the processor (108). The processor (108) can also combine this data with the previously-obtained data about the size of aggregates and use a set of relevant user-provided data and standards (108) to present the optimal percentage of each material, water, and cement to obtain and show the optimum concrete on the display (125), enabling the user to produce concrete based on these percentages. The data and standards the user presents to the processor in advance (108) cover the optimum concrete for the different geographical locations provided in concrete codes. With this data and the data received from the GPS sensor (133), the processor (108) can determine the optimum type of cement, the required water content, and other data to recommend an optimal mix design to the user.

Advantageous Effects of Invention

[0019] 1. The system disclosed in this written application can provide an optimal mix for aggregate gradation, ensuring the user that the gradation curve of the aggregate used in concrete is within the standard range.

[0020] 2. Given the disclosed system's portability and relatively small size, it can be used everywhere, including small plants.

[0021] 3. Since the system does not require expertise, it can be easily operated by a normal user.

[0022] 4. This system is made cost-effective by virtue of its components, increasing the justification for its use.

[0023] 5. The disclosed system eliminates the need for laboratory experiments and expensive equipment, reducing total costs.

[0024] 6. Since the system is used in construction plants without transferring samples to laboratory, it can save a great deal of time in concrete production. Brief Description of Drawings

[0025] Figure (1A) shows a 3D representation of a concrete mix design system (100) that is compatible with one or several implementations of this invention.

[0026] Figure (1 B) shows a 3D cross-section of a system (100) that is compatible with one or several implementations of this invention.

[0027] Figure (1C) shows a side cross-section of a system (100) that is compatible with one or several implementations of this invention.

[0028] Figure (1 D) shows an oblique cross-section of a system (100) that is compatible with one or several implementations of this invention.

[0029] Figure (2A) shows a standard gradation area that is compatible with one or several example implementations of this invention.

[0030] Figure (2B) shows a curve of optional grading requirements for fine aggregate (e.g., sand) and coarse aggregate (e.g., gravel) in concrete obtained from existing standards and regulations.

Description of Embodiments

[0031] 100 3D representation of a concrete mix design system

[0032] 102 Main body

[0033] 103 Material holding tray

[0034] 104 Vibration table

[0035] 105 Vibration mechanism

[0036] 106 The lighting system

[0037] 107 Imaging system

[0038] 108 Processor

[0039] 109 LIDAR module

[0040] 122 Upper chamber

[0041] 123 User-interface console

[0042] 124 Lower chamber [0043] 125 Display

[0044] 126 Four legs

[0045] 131 Temperature sensor

[0046] 132 Humidity sensor

[0047] 133 GPS sensor

[0048] 135 Solar cell

[0049] 152 First vibration motor

[0050] 153 Second vibration motor

[0051] 201 The lower limit curve

[0052] 202 The upper limit curve

[0053] 203 Curve

[0054] 1522 First axle

[0055] 1523 Second axle

[0056] 1541 First spring

[0057] 1542 Second spring

[0058] 1543 Third spring

[0059] 1544 Fourth spring

Examples

[0060] For example, assume that concrete requires the mixture of two materials for aggregate preparation. The first material is a fine aggregate (e.g., sand) and the second material is coarse aggregate (e.g., gravel). First, it is worth stressing that there will be no difference in the system's function if aggregate production requires the mixture of more materials. In simpler terms, the example uses an aggregate obtained by the mixture of two materials. First, the user pours some of the first material (e.g., approximately 500 grams) on the material holding tray (103) and places the material holding tray (103) on the vibration table (104). Then, as mentioned earlier, the first vibration motor (152) and the second vibration motor (153) are activated, the material holding tray (103) is vibrated and the first material’s aggregates on the surface of the material holding tray (103) are spread such that no two aggregates land on top of each other and the aggregates land on their largest dimension. Then, the lighting system (106) is activated to illuminate the aggregates of the first materials. Next, the imaging system (107) takes and sends the image of the aggregates for the first materials to the processor (108).

[0061] The processor (108) employs state-of-the-art image processing algorithms to obtain and store the size of the first material's aggregates in its memory as data related to the first materials.

[0062] Then, the user empties the material holding tray (103) from the first material and pours a certain amount of the second material (e.g., approximately 500 grams) on the material holding tray (103) and places it on the vibration table (104). The process continues similarly to the first material until the processor (108) stores data about the size of the second material’s aggregates in its memory. Then, the processor (108) can use the data about the aggregate size of the first and second materials to obtain the gradation curve of different mixes of the two materials. For example, the processor (108) can use the data on the aggregate size of the first and second materials to predict the gradation curve of the material obtained by mixing 1% of the first materials and 99% of the second materials. The process continues for materials obtained by mixing 2% of the first material and 98% of the second material until the prediction of the gradation curve of the material obtained by mixing 99% of the first material and 1% of the second material.

[0063] Then, based on the standard gradation areas available in the relevant references and the conditions and application of concrete, the user provides a gradation area such as the area shown in Figure 2A to the processor (108), and the processor compares the gradation curve obtained in the previous step with the user-defined gradation curve. If the curve is completely inside the standard gradation area, the mix percentages will be displayed to the user. Note that when a gradation curve is entirely within the standard gradation area, it is higher than the lower limit and lower than the upper limit of the standard, and based on the standard, the material has the optimum size distribution of aggregates. Therefore, the user will be ensured that these percentage will produce materials with an aggregate size and distribution within the standard range.

[0064] Moreover, the user also provides data to the processor (108) about the composition of concrete components based on different environmental conditions, which can be obtained from relevant references. The processor (108) collects temperature and humidity data from the temperature (131) and humidity sensor (132) and combines this data with user data to obtain the necessary percentage of the first material, second material, water, and cement. It is then shown on the display to ensure the user that the use of these percentages will place the aggregate gradation curve within the standard range, resulting in a standard and optimal mix design within the defined ranges.

Industrial Applicability

[0065] When used in small and large plant environments, the proposed system can produce a mixture of materials (e.g., sand and gravel) with which the aggregate mix used for concrete production has a gradation within the standard limit. The disclosed system also offers the user a mix design within the standard limit. This system eliminates the need to send material samples to the laboratory for analyzing aggregate size and obtaining the gradation curve and provides the required percentage of materials and the mix design in the plant.