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CN-121989362-A - Regulation and control method for machine-made sand concrete construction

CN121989362ACN 121989362 ACN121989362 ACN 121989362ACN-121989362-A

Abstract

The invention discloses a regulation and control method for machine-made sand concrete construction, belongs to the technical field of building material concrete preparation, and aims to solve the problems that in the prior art, the working performance of concrete is unstable, regulation and control depend on manual experience and lack of systematicness due to fluctuation of machine-made sand characteristics. The method comprises the steps of firstly establishing a standard mix proportion and a machine-made sand standard characteristic file, carrying out initial adaptation by comparing measured characteristics, continuously monitoring the water content of the machine-made sand in the production process, synchronously monitoring the driving current of a stirrer and the apparent state of a mixture, judging that performance deviation risks exist when the parameters exceed a preset threshold, then respectively executing hierarchical regulation and control based on calculation or a pre-stored decision table aiming at risks indicated by the fluctuation of the water content or the current and the apparent state, and revising the material consumption compensation relation and decision parameters according to recorded production data after each production batch is finished. The invention is mainly used for realizing the self-adaptive regulation and control of the working performance of the machine-made sand concrete in the production process.

Inventors

  • Miao xiangda
  • YIN MIN
  • XU XIAOKANG
  • QIU ZHOU
  • NIU YANJUN

Assignees

  • 中交第三公路工程局有限公司

Dates

Publication Date
20260508
Application Date
20260127

Claims (9)

  1. 1. A regulation and control method for machine-made sand concrete construction is characterized by comprising the following steps: The method comprises the steps of (1) establishing a standard reference mix ratio for concrete with different strength grades and workability requirements, establishing standard characteristic files containing stone powder content and grading for machine-made sand with different sources, obtaining actual measurement characteristic parameters of the machine-made sand in the current batch, comparing the actual measurement characteristic parameters with the corresponding standard characteristic files, and correcting the selected standard mix ratio according to the corresponding relation between the predefined material characteristic offset and the material consumption compensation value to generate an initial production mix ratio; monitoring core parameters, namely continuously monitoring the actual water content of the machine-made sand by utilizing an online water content detection device in the stirring production process according to the initial production mixing proportion; The multi-source auxiliary sensing and early warning step (3) is that in the stirring process, the driving current or torque of the stirrer is synchronously monitored, and the apparent state information of the mixture is obtained at a preset node; Step (4) of grading decision and execution, when the performance deviation risk is judged, If the risk is caused by the fluctuation of the water content, calculating and adjusting the total water consumption in the production mixing ratio according to the variation of the water content; If the risk is indicated by the driving current and the apparent state information when the water content is stable, inquiring a pre-stored decision table according to the change mode and the apparent state information of the driving current to determine the regulation and control direction as regulating the admixture doping amount or the sand content, and executing according to the regulating amount appointed by the decision table; And (5) experience feedback and parameter updating, namely recording the final mix proportion, process monitoring data and actual measurement working performance of each production batch after the production batch is finished to form a production record, and revising the corresponding relation of the material consumption compensation value and the regulation and control parameters in the decision table based on the production record.
  2. 2. The method for controlling construction of machine-made sand concrete according to claim 1, wherein in the step (1), the correction is performed according to the correspondence between the predefined material characteristic offset and the material usage compensation value, specifically: Calculating a specific surface area adjustment coefficient K1 and a void ratio adjustment coefficient K2 of the current machine-made sand according to the difference between the stone powder content in the actually measured characteristic parameter and the reference stone powder content in the standard characteristic file and the difference between the actually measured grading curve and the reference grading curve; Adjusting the machine-made sand dosage and the admixture dosage in the selected reference mix proportion respectively through a machine-made sand dosage correction value delta S=f (K1, K2) and an admixture dosage correction value delta Ad=g (K1) to generate the initial production mix proportion; Wherein the function f is a predefined relation based on the influence of the specific surface area and the void ratio on the aggregate skeleton, and the function g is a predefined relation based on the influence of the specific surface area on the water demand and the additive adsorption amount.
  3. 3. The method for controlling machine-made sand concrete construction according to claim 1 or 2, wherein the setting method of the second preset threshold is as follows: monitoring an idle driving current value or an idle torque value of the mixer when the mixer is in an idle state; after stirring according to the initial production mixing proportion and reaching a stable state, monitoring a steady-state load current value or a steady-state load torque value of the stirring; Taking the difference value of the no-load value and the steady-state load value as a reference variation, taking the reference variation of the steady-state load value added with a preset proportion as an early warning upper limit value of driving current or torque, and taking the reference variation of the steady-state load value subtracted with the preset proportion as an early warning lower limit value; The early warning upper limit value and the early warning lower limit value form the second preset threshold value.
  4. 4. The method for controlling construction of machine-made sand concrete according to claim 3, wherein in the step (3), the trend of the driving current or torque is verified in an auxiliary manner, and the method specifically comprises the steps of: when the real-time value of the driving current or torque exceeds the second preset threshold value, the risk of performance deviation is not immediately judged, and whether a preset interference event exists in a preset association period or not is synchronously checked; the disturbance event comprises an event of throwing large aggregates by the mixer according to a preset sequence, an event of carrying out large-angle tilting and unloading by the mixer or an equipment abnormality alarm event recorded by a production control system; if any interference event exists in the association period, the super-threshold signal of the driving current or the torque is ignored, and is not used as a basis for judging the performance deviation risk; And if the interference event does not exist in the association period, confirming that the change trend of the driving current or the torque exceeds a second preset threshold value.
  5. 5. The method for controlling construction of machine-made sand concrete according to claim 4, wherein the pre-stored decision table in the step (4) is a hierarchical decision table, and the construction and query methods are as follows: Dividing the decision table into a first-stage decision layer and a second-stage decision layer; The first-stage decision layer takes a single dominant abnormal mode as an index item, wherein the dominant abnormal mode is defined by one item with the most obvious characteristics in the combination of the variation mode of the driving current and the apparent state information; The second-stage decision layer takes the severity level of the dominant abnormal mode as an index item, and the severity level is divided according to the amplitude and duration time when the driving current or torque exceeds a second preset threshold value; when deciding, firstly determining dominant abnormal mode according to real-time perception information, inquiring the first-stage decision layer to obtain preliminary direction, and then activating the corresponding second-stage decision layer according to the severity of current abnormality, inquiring to obtain specific adjustment quantity.
  6. 6. The method for controlling construction of machine-made sand concrete according to claim 5, wherein the method for determining the control direction and the adjustment amount in the second-stage decision layer is as follows: presetting a reference adjustment quantity unit for the specific regulation and control direction corresponding to each type of dominant abnormal mode; the severity level is associated with an adjustment factor, wherein a higher severity level corresponds to a greater adjustment factor; The specific adjustment amount is calculated and determined by multiplying the reference adjustment amount unit by the corresponding adjustment multiple.
  7. 7. The method for controlling machine-made sand concrete construction according to any one of the claims 4 to 6, wherein, In step (3), when the trend of the driving current or torque is determined to exceed the second preset threshold, and it is verified that no disturbance event is found, but the apparent state information acquired synchronously indicates that there is an abnormality, the following conflict resolution process is performed: Firstly, judging whether the apparent state information indicates segregation or severe bleeding phenomenon of the mixture, if so, ignoring the variation trend of the driving current, directly taking the apparent state information as a basis, entering a grading decision and execution stage of the step (4), and determining the regulation and control direction to adjust the sand ratio or reduce the slurry redundancy; If not, then judging whether the variation trend of the driving current is continuously rising or continuously falling, if so, entering the grading decision and execution stage of the step (4) based on the variation trend of the driving current; if the variation trend of the driving current is that the variation trend has no clear direction fluctuation, judging that the state is stable, returning to the step (3) to monitor continuously, and shortening the preset node interval for acquiring the apparent state information subsequently.
  8. 8. The method for controlling construction of machine-made sand concrete according to claim 1, wherein the corresponding relation of the compensation value of the material consumption and the controlling parameters in the decision table in the step (5) are revised, specifically by the following steps: Screening out production batch data which has actual measurement working performance meeting preset qualification standards, stable production process, no triggering of the performance deviation risk early warning or only triggering and single regulation execution from the production record, and taking the production batch data as an effective revision sample; Comparing the final adopted mix ratio parameter with the mix ratio parameter generated by the system under the same initial condition according to the original corresponding relation and the decision table aiming at each effective revision sample, and calculating the parameter offset of the actual adopted value and the original output value of the system under the same regulation and control target; and (c) gradually revising, namely revising the compensation value in the corresponding relation or the regulation and control parameter in the decision table in the same direction based on the parameter offset, wherein the amplitude of single revising does not exceed the preset proportion of the absolute value of the parameter offset.
  9. 9. The method for controlling construction of machine-made sand concrete according to claim 8, wherein the data choose in step (a) is used for selecting the production process stability to comprehensively judge by the following quantization indexes: (i) The total duration from the start of stirring to the end of stirring of the production batch is within the range of standard stirring duration preset for the batch mixing ratio; (ii) During the stirring process of the production batch, the real-time value of the driving current or the torque exceeds the accumulated duration of the second preset threshold value and is lower than a preset time duty ratio threshold value; (iii) The total number of times of the grading decision and execution of the production batch triggered in the step (4) does not exceed a preset number of times threshold; if and only if conditions (i), (ii) and (iii) are simultaneously satisfied, it is determined that the production process of the production lot is smooth.

Description

Regulation and control method for machine-made sand concrete construction Technical Field The invention belongs to the technical field of building material concrete preparation, and particularly relates to a regulation and control method for machine-made sand concrete construction. Background In the concrete ready-mix industrial production, maintaining the stability of the working performance of the concrete mixture is a key for guaranteeing the construction quality and efficiency. Machine-made sand is increasingly used as an important fine aggregate source, but its inherent fluctuation in material properties presents significant challenges for stable control of concrete production. Unlike natural sand, the machine-made sand is formed by rock breaking, and key characteristics of particle morphology (polygonal angles), stone powder content, particle grading and the like are not only influenced by the lithology of the parent rock, but also directly influenced by breaking equipment, screening process and fluctuation of production batches. Thus, the characteristic parameters of the machine-made sand (such as stone dust content, fineness modulus, water content) tend to exhibit significant intra-batch and inter-batch fluctuations. The fluctuation can directly cause the theoretical requirements of key components (particularly water consumption, admixture mixing amount and sand rate) in the concrete mixing ratio to change, and if the concrete is produced by adopting a fixed mixing ratio, the deviation of working performance indexes such as concrete slump, expansion degree and the like is extremely easy to cause site construction difficulty, hidden quality hazards or material waste. At present, the response to the fluctuation of the characteristics of the machine-made sand in the production in the industry mainly depends on two modes, but has limitations. The first approach relies on laboratory "pre-existing" detection and mix adjustment. After each batch of machine-made sand enters the field, sampling is carried out for laboratory detection, and the mixing ratio is recalculated or adjusted according to the detection result. This approach, while accurate, has serious hysteresis. From sampling, detection, the adjustment scheme often requires several hours, and cannot meet continuous and fast-paced production requirements. During the inspection, large amounts of sand that have entered the field may have been used, resulting in unstable properties of the produced concrete. At the same time, frequent laboratory retests also increase labor and time costs. The second approach relies on "in-the-event" empirical control of the operator of the mixing plant. In the production process, an operator manually fine-adjusts the water consumption or the admixture dosage by personal experience through empirical means such as observing stirring current, visual observation of the state of the mixture and the like. Although the method is direct, the accuracy, timeliness and consistency of regulation and control are difficult to guarantee. First, this experience is highly dependent, and the judgment standards and adjustment scales of different operators are different, resulting in unstable regulation results. Secondly, human eye observation and subjective judgment are easy to interfere and fatigue, and early and accurate early warning is difficult to be carried out on the tiny change trend of concrete workability. More importantly, operators can only adjust the most sensitive water consumption, and the system analysis and comprehensive regulation capability are lacked for complex changes of water demand, additive adsorptivity and aggregate framework structure caused by stone powder content and grading change, so that the symptoms and root causes are often not treated. For example, when the machine-made sand is graded and thin and the specific surface area is increased, the fluidity can be improved briefly by only increasing the water consumption, but the excessive slurry can be caused, the problems of segregation, bleeding, strength loss and the like are caused, and the adjustment of the sand ratio or the admixture can be a more fundamental solution. Therefore, the concrete production industry has long faced with a prominent difficulty of quickly and accurately responding to real-time fluctuation of the machine-made sand characteristics in the actual continuous production process, and not only relying on single moisture compensation, but also being capable of systematically and adaptively dynamically adjusting the concrete mixing ratio. The difficulty in achieving this is that firstly, an effective method capable of sensing key influencing factors (especially the influence of material characteristics outside the water content) on line in real time needs to be established, secondly, a clear and executable decision logic needs to be established between complex material characteristic changes and adjustment amounts of various mixing ratio p