A high-slump-retaining high-fluidity concrete admixture compounding method

Abstract

The application discloses a high-slump high-fluidity concrete additive compounding method, which comprises the following steps: (1) adopting polycarboxylic acid water reducing agent mother liquor and sodium metabisulfite to adjust the concrete out-machine state, and determining the polycarboxylic acid water reducing agent mother liquor and sodium metabisulfite dosages; (2) adopting sodium gluconate, sodium tripolyphosphate and sodium hexametaphosphate to control the 30 min slump of the concrete, and determining the sodium gluconate, sodium tripolyphosphate and sodium hexametaphosphate dosages; (3) adopting polycarboxylic acid slump-retaining mother liquor to control the time loss of the concrete, and determining the polycarboxylic acid slump-retaining mother liquor dosage; and (4) adopting polycarboxylic acid slump-retaining mother liquor to control the 2 h slump of the concrete, and determining the polycarboxylic acid slump-retaining mother liquor dosage. The scheme provided by the application can relatively accurately determine the dosages of various components of the comprehensive concrete additive in modern engineering, so that the cost is reduced and the quality is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to building materials, in particular to concrete admixture compounding technology. BACKGROUND

[0002] At present, due to the serious decline in the quality of raw materials in the civil engineering industry, the use of a single admixture is not enough to make the comprehensive performance of concrete meet the construction requirements. In the production of concrete, the use of compounding method to obtain comprehensive admixture has become the most commonly used technical means in the field.

[0003] However, the current admixture compounding scheme mainly has the following problems:

[0004] (1) The compounding mainly relies on experience, and lacks systematic theory and method support.

[0005] (2) In the face of poor quality concrete materials, the compounding cost is extremely high, and there is a lack of effective cost control measures.

[0006] (3) The work performance is urgently guaranteed, so that the concrete admixture content is too high, which has an adverse effect on the durability of concrete.

[0007] Therefore, it is urgent to provide a concrete admixture compounding scheme which is easy to implement and the implementation effect is controllable. SUMMARY

[0008] In view of the problems existing in the compounding scheme used in the production of concrete at present, the purpose of the present application is to provide a high slump and high fluidity concrete admixture compounding method, which realizes efficient and high-quality completion of concrete admixture compounding.

[0009] In order to achieve the above purpose, the high slump and high fluidity concrete admixture compounding method provided by the present application comprises:

[0010] (1) The polycarboxylic acid water reducing agent mother liquor and sodium metabisulfite are used to adjust the concrete out-machine state, and the amount of polycarboxylic acid water reducing agent mother liquor and sodium metabisulfite is determined;

[0011] (2) Sodium gluconate, sodium tripolyphosphate and sodium hexametaphosphate are used to control the 30min slump of concrete, and the amount of sodium gluconate, sodium tripolyphosphate and sodium hexametaphosphate is determined;

[0012] (3) The polycarboxylic acid slump retaining mother liquor is used to control the loss over time of concrete, and the amount of polycarboxylic acid slump retaining mother liquor is determined;

[0013] (4) The polycarboxylic acid slump retaining mother liquor is used to control the 2-hour slump of concrete, and the amount of polycarboxylic acid slump retaining mother liquor is determined.

[0014] Furthermore, in step (1) of the compounding method, when determining the dosage of polycarboxylate superplasticizer mother liquor and sodium metabisulfite, if the slump of the concrete leaving the machine has not reached T, the dosage of polycarboxylate superplasticizer mother liquor is first increased according to the ratio; if the slump of the concrete leaving the machine reaches T, but after 5 to 10 minutes, the concrete bottoms out and the slump loss reaches more than 40%, the dosage of sodium metabisulfite is increased.

[0015] Furthermore, in step (2), the admixtures obtained in step (1) are used in the compounding method. After the mixed concrete is left to stand for 30 minutes after being discharged from the mixer, a slump test is performed, and sodium gluconate, sodium tripolyphosphate, and sodium hexametaphosphate are added according to the loss.

[0016] Furthermore, in step (2), sodium gluconate is first added to the compounding method, and the amount of sodium gluconate added is determined according to the slump of the concrete after it has been left to stand for 30 minutes after being discharged from the machine.

[0017] Furthermore, in step (2) of the compounding method, after adding sodium gluconate, severe bottoming and slurry-aggregate separation of the concrete occurred after it left the machine, sodium tripolyphosphate and sodium hexametaphosphate were added instead; and the dosage of sodium tripolyphosphate and sodium hexametaphosphate was determined according to the slump of the concrete after it had been left to stand for 30 minutes after leaving the machine.

[0018] Furthermore, in step (2) of the compounding method, sodium tripolyphosphate and sodium hexametaphosphate are added in a 1:1 ratio.

[0019] Furthermore, in step (3), the admixture obtained in step (2) is used in the compounding method. One hour after the concrete is discharged from the mixer, the slump is tested, and the amount of polycarboxylate slump-preserving mother liquor added is adjusted according to the loss.

[0020] Furthermore, the amount of the slump-preserving mother liquor used is positively correlated with the amount of adhesive material used.

[0021] Furthermore, in the compounding method, the admixture obtained in step (3) is used in step (4). Two hours after the concrete is discharged from the mixer, the slump is tested, and the amount of polycarboxylate slump-preserving mother liquor is adjusted according to the loss.

[0022] The high-slump-holding and high-fluidity concrete admixture compounding scheme provided by this invention has the following technical advantages over the prior art:

[0023] (1) The solution provided by the present invention can relatively accurately determine the dosage of each component of the comprehensive admixture for modern engineering concrete, so as to reduce costs and improve quality.

[0024] (2) The scheme provided by the application can match each component of the admixture with the state of the concrete at each time period, can play the efficiency of each component of the admixture, avoids invalid tests, and improves the compounding efficiency of the admixture. BRIEF DESCRIPTION OF DRAWINGS

[0025] The application will be further described below in combination with the drawings and specific embodiments.

[0026] Figure 1 The specific implementation flowchart of the application is as follows. DETAILED DESCRIPTION

[0027] In order to make the technical means, creative features, purposes and effects of the application easy to understand, the application is further described below in combination with specific drawings.

[0028] The application gives a high-slump high-fluidity concrete admixture compounding scheme in view of the problems of the admixture compounding scheme used in the production of concrete described in the background art, the admixture compounding scheme realizes the compounding of the admixture components in steps, and the admixture components and the amount of each step are determined in correspondence with the state of the concrete, that is, the realization of the correspondence between the admixture components and the state of the concrete in steps.

[0029] Specifically, the high-slump high-fluidity concrete admixture compounding scheme given by the application involves compounding components raw materials mainly including polycarboxylic acid water-reducing mother liquor, polycarboxylic acid slump-retaining mother liquor, sodium gluconate, sodium tripolyphosphate, sodium hexametaphosphate and sodium metabisulfite.

[0030] As a preferred, the polycarboxylic acid water-reducing mother liquor and the polycarboxylic acid slump-retaining mother liquor in the scheme meet the relevant requirements of GB8076 and GB8077, and the solid content reaches 40±2%; further, the sodium tripolyphosphate, the sodium hexametaphosphate and the sodium metabisulfite in the scheme are all industrial grade.

[0031] The object to which the compounding scheme is preferably directed is specifically concrete with a designed slump T≥200mm, a 2-hour slump loss less than 5% and a C50 or below.

[0032] Accordingly, the high-slump high-fluidity concrete admixture compounding scheme given by the application realizes the compounding of the admixture in four steps according to the performance state changes in the production of concrete, and the corresponding relationship between the admixture compounding components and the state of the concrete in each step is shown in Table 1:

[0033] Table 1: Corresponding relationship between admixture components and concrete performance

[0034] Step Concrete performance Main components of admixture 1 Slump in 0-10 min Polycarboxylic acid water-reducing mother liquor, sodium metabisulfite 2 Slump in 30 min Sodium gluconate, sodium tripolyphosphate, sodium hexametaphosphate 3 Loss over time Polycarboxylic acid slump-retaining mother liquor 4 Slump in 2 hours Polycarboxylic acid slump-retaining mother liquor

[0035] Therefore, the specific process of the high-slump-retaining high-fluidity concrete admixture compounding scheme provided by the application is as follows:

[0036] Step (1): The concrete out-of-machine state is adjusted by using polycarboxylate superplasticizer mother liquor and sodium metabisulfite, and the dosages of the polycarboxylate superplasticizer mother liquor and the sodium metabisulfite are determined.

[0037] Step (2): The 30 min slump of the concrete is controlled by using sodium gluconate, sodium tripolyphosphate and sodium hexametaphosphate, and the dosages of the sodium gluconate, the sodium tripolyphosphate and the sodium hexametaphosphate are determined.

[0038] Step (3): The time loss of the concrete is controlled by using polycarboxylate slump-retaining mother liquor, and the dosage of the polycarboxylate slump-retaining mother liquor is determined.

[0039] Step (4): The 2 h slump of the concrete is controlled by using polycarboxylate slump-retaining mother liquor, and the dosage of the polycarboxylate slump-retaining mother liquor is determined.

[0040] Based on the foregoing scheme, the implementation process of the high-slump-retaining high-fluidity concrete admixture compounding scheme provided by the application is specifically described as follows.

[0041] Referring to Figure 1 which is a specific implementation flowchart of the high-slump-retaining high-fluidity concrete admixture compounding scheme in the application.

[0042] As shown in the figure, the specific process of the high-slump-retaining high-fluidity concrete admixture compounding process is as follows:

[0043] Step 1. Adjustment of the concrete out-of-machine state.

[0044] In this step, the concrete is adjusted according to the corresponding regulations, and after the raw materials are fully stirred in the mixer (including only the addition of the superplasticizer mother liquor), the corresponding out-of-machine state is determined.

[0045] In some embodiments, the out-of-machine state is determined by the following sub-steps in this step 1.

[0046] (1.1) Out-of-machine slump test:

[0047] If the slump does not reach T, the dosage of the polycarboxylate superplasticizer mother liquor is increased in proportion.

[0048] Here, the dosage of the polycarboxylate superplasticizer mother liquor is increased according to the following formula:

[0049] Dosage of the superplasticizer mother liquor = (T / actual slump) * original dosage of the superplasticizer mother liquor.

[0050] Since the dosage of water-reducing mother liquor is basically in direct proportion to the water-reducing rate of the additive and the slump of the concrete out of the machine, the reasonable dosage of the water-reducing mother liquor can be effectively determined according to the proportional relationship between the dosage of the water-reducing mother liquor and the measured slump.

[0051] (1.2) Slump test after out of the machine:

[0052] If the slump out of the machine reaches T, but the concrete has a grab bottom and the slump loss reaches more than 40% within 5-10 minutes after out of the machine, it is determined that the content of gypsum in the glue material is insufficient, resulting in too large slump loss, and the dosage of sodium hydrosulfite is increased.

[0053] It should be noted here that the dosage of sodium hydrosulfite in this step is determined according to the content of C3A in the glue material, and does not exceed 0.91 times the mass of C3A in the glue material. As a preferred, generally 10-40 Kg of sodium hydrosulfite is added per ton of water-reducing agent to achieve good adjustment effect.

[0054] Through the cooperation of sub-step (1.1) and sub-step (1.2) in this step, the target of the out-of-machine state is "the slump of the concrete does not lose within 10 minutes after out of the machine"; and the dosage of the polycarboxylic acid water-reducing mother liquor and sodium hydrosulfite in the additive when the target is reached is determined.

[0055] Step 2. Adjustment of the state of the concrete out of the machine for thirty minutes.

[0056] In this step, the additive adjusted in step 1 is used to mix the concrete, and the slump is detected after the concrete is left for thirty minutes. According to the loss, sodium gluconate, sodium tripolyphosphate, sodium hexametaphosphate and other retarding components are added, and the dosage is determined.

[0057] In some embodiments, the out-of-machine state in this step 2 is determined by the following sub-steps:

[0058] (2.1) Gluconate sodium addition test.

[0059] Set the slump of the concrete out of the machine for thirty minutes without adding gluconate sodium as t301. In this step, gluconate sodium a kg is tentatively added to obtain the 30-minute slump t302; and the gluconate sodium addition amount A is determined as A=a+(T-t302) / [(t302-t301) / a].

[0060] Gluconate sodium is commonly used as a retarding admixture in concrete. In this example, gluconate sodium is added to the concrete within 30 minutes, and the gluconate sodium will simultaneously play a water-reducing and slump-retaining role

[0061] It is found through research and a large number of experiments that the amount of sodium gluconate and the slump loss of concrete in 30 minutes basically obey a linear relationship. In this example, the amount of sodium gluconate is determined according to the above linear equation, so that the amount of sodium gluconate can be effectively and accurately determined.

[0062] Accordingly, the specific amount of sodium gluconate in this step is determined according to the amount of glue material, and does not exceed 0.1% of the amount of glue material; at the same time, the general amount in each ton of additive does not exceed 40 kg.

[0063] If the concrete out of the machine appears serious bottom grabbing and paste stone separation phenomenon after adding sodium gluconate, sodium gluconate should not be used as a retarder, and sodium tripolyphosphate and sodium hexametaphosphate should be used instead.

[0064] (2.2) Add sodium tripolyphosphate and sodium hexametaphosphate test.

[0065] The amount of sodium tripolyphosphate and sodium hexametaphosphate in this step is determined in the same way as the amount of sodium gluconate in step (2.1). At the same time, sodium tripolyphosphate and sodium hexametaphosphate are added in a ratio of 1:1 to avoid serious impact on the acid-base degree of concrete paste.

[0066] Through the mutual cooperation of sub-step (2.1) and sub-step (2.2) in this step, the target of adjusting the state of concrete out of the machine in 30 minutes is "concrete out of the machine in 30 minutes, slump loss", and thus the amount of sodium gluconate, sodium tripolyphosphate, sodium hexametaphosphate and other retarding components in the additive when the target is reached is determined.

[0067] Step 3. Adjustment of concrete out of the machine in one hour.

[0068] In this step, the additive obtained by adjusting step 2 is used to mix concrete out of the machine in one hour, and the slump loss is detected and observed. According to the loss, the amount of polycarboxylic acid slump retention mother liquor is added. The amount of polycarboxylic acid slump retention mother liquor in this step is positively correlated with the amount of glue material.

[0069] Because the additive contains retarding components (sodium gluconate, sodium tripolyphosphate, sodium hexametaphosphate, etc. in step 2), the slump in one hour out of the machine will not decrease to 0 without adding the slump retention mother liquor. Accordingly, the amount of polycarboxylic acid slump retention mother liquor is determined by two exploratory additions in this step: adding slump retention mother liquor b1 kg and b2 kg, respectively, to obtain the slump T1 and T2 of concrete out of the machine in one hour; thus, the amount of polycarboxylic acid slump retention mother liquor B = (T-t2)*(b2-b1) / (t2-t1)+b2 is determined.

[0070] Through research and a large number of experiments, it is found that the dosage of the slump retention mother liquor and the time loss of the concrete are in linear relationship. Meanwhile, the water reducing mother liquor and sodium gluconate have certain slump retention capacity, so twice tentative additions are carried out to determine the dosage of the slump retention mother liquor based on the first step and the second step to ensure the accuracy of the dosage.

[0071] In this step, the target of adjusting the state of the concrete one hour after leaving the machine is "the concrete leaving the machine for one hour, and the slump loss is not lost". Thus, the dosage of the polycarboxylic slump retention mother liquor in the additive when the target is reached is determined.

[0072] Step 4. Adjustment of the state of the concrete two hours after leaving the machine.

[0073] In this step, the additive obtained by adjusting in step 3 is used to mix the concrete, and the slump loss is detected after the concrete leaves the machine for two hours. According to the loss, the dosage of the polycarboxylic slump retention mother liquor is adjusted.

[0074] In this step, first, the additive obtained by adjusting in step 3 is used to mix the concrete, and the slump loss test is carried out to determine whether the slump loss can be kept within 5%. If not, the dosage of the slump retention mother liquor is added according to the slump T+10mm:

[0075] That is, the dosage of the slump retention mother liquor is B=(T+10-t2)*(b2-b1) / (t2-t1)+b2.

[0076] Thus, the dosage of the polycarboxylic slump retention mother liquor in the additive is obtained.

[0077] Thus, according to the aforementioned steps 1-4, the dosages of the polycarboxylic water reducing mother liquor, the polycarboxylic slump retention mother liquor, sodium gluconate, sodium tripolyphosphate, sodium hexametaphosphate and sodium metabisulfite in the concrete additive can be determined.

[0078] The application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the application and are not used to limit the scope of the application. In the following examples, the experimental methods not specified are generally determined according to the national standards. If there is no corresponding national standard, the methods are carried out according to the general international standards, conventional conditions, or the conditions recommended by the manufacturers.

[0079] Unless otherwise defined or specified, all professional and scientific terms used herein have the same meaning as familiar to those skilled in the art. In addition, any method and material similar or equivalent to those described can be applied to the method of the application.

[0080] For convenience of description, in the following examples, the dosages of all components of the additive are represented in the mass of each component added in 1 ton of the additive, rather than the mass added in the concrete mixture.

[0081] Meanwhile, the polycarboxylic acid water-reducing mother liquor is referred to as water-reducing mother liquor, and the polycarboxylic acid slump-retaining mother liquor is referred to as slump-retaining mother liquor.

[0082] Example 1

[0083] The mixing ratio of a certain C30 concrete is cement: fly ash: sand: gravel: water = 267: 101: 817: 1053: 149. The designed slump is 200 ± 20 mm. The designed dosage of the admixture is 1%.

[0084] The initial admixture components are water-reducing mother liquor: slump-retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: water = 200: 0: 0: 0: 0: 0: 800.

[0085] Accordingly, the process of compounding the concrete admixture in this example is as follows:

[0086] Step 1, the concrete is discharged from the machine, and the slump is 210 mm. Within 10 minutes, the slump is not lost.

[0087] Step 2, the concrete is discharged from the machine for 30 minutes, and the slump is lost to 140 mm.

[0088] Add 10 kg of sodium gluconate, and discharge the machine for 30 minutes. The slump is lost to 170 mm. The dosage of sodium gluconate is 10 + (210-170) / [(170-140) / 10] = 23 kg.

[0089] Step 3, according to the admixture of water-reducing mother liquor: slump-retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: water = 200: 0: 23: 0: 0: 0: 777, mix the concrete and discharge the machine for one hour, and the slump is 160 mm. Add 60 kg of slump-retaining mother liquor, and the slump is 180 mm after one hour. Add 80 kg of slump-retaining mother liquor, and the slump is 200 mm after one hour. Therefore, the dosage of slump-retaining mother liquor is 90 kg.

[0090] Step 4, according to the admixture of water-reducing mother liquor: slump-retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: water = 200: 90: 23: 0: 0: 0: 800, mix the concrete and discharge the machine for two hours, and the slump is 210 mm. No further adjustment of the admixture is needed.

[0091] Accordingly, the admixture formula for the C30 concrete obtained in this example is water-reducing mother liquor: slump-retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: water = 200: 90: 23: 0: 0: 0: 687.

[0092] Example 2

[0093] The C25 concrete mix ratio is cement: fly ash: sand: gravel: water = 222: 100: 852: 1075: 152. The designed slump is 200 ± 20 mm. The designed dosage of admixture is 1%.

[0094] The initial admixture components are water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 180: 0: 0: 0: 0: 0: 820.

[0095] Accordingly, the process of compounding the concrete admixture in this example is as follows:

[0096] Step 1, the concrete is discharged from the machine, the slump is 210 mm, within 10 minutes, the slump loss is to 90 mm. Add 30 kg of sodium pyrosulfite, the concrete is discharged from the machine, the slump is 215 mm, after 10 minutes, the slump is not lost.

[0097] Step 2, according to the water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 180: 0: 0: 0: 0: 30: 790. Mix the concrete and discharge from the machine for 30 minutes, the slump loss is to 140 mm. Add 20 kg of sodium gluconate, discharge from the machine for 30 minutes, the slump loss is to 180 mm. The dosage of sodium gluconate is 20 + (210-180) / [(180-140) / 10] = 27.5 kg.

[0098] Step 3, according to the water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 180: 0: 27.5: 0: 0: 30: 762.5, admixture is compounded, mix the concrete and discharge from the machine for one hour, the slump is 160 mm. Add 60 kg of slump retaining mother liquor, the slump is 180 mm after one hour, add 80 kg of slump retaining mother liquor, the slump is 200 mm after one hour. The dosage of slump retaining mother liquor is 90 kg.

[0099] Step 4, according to the water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 180: 90: 27.5: 0: 0: 30: 672.5, admixture is compounded, mix the concrete and discharge from the machine for two hours, the slump is 190 mm. The dosage of slump retaining agent is adjusted to 100 kg.

[0100] Accordingly, the admixture formula for the C30 concrete obtained in this example is water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 180: 100: 27.5: 0: 0: 30: 662.5.

[0101] Example 3.

[0102] The mixing proportion of the C35 concrete is cement: fly ash: sand: gravel: water = 290: 102: 793: 1055: 150. The designed slump is 200 ± 20 mm. The designed dosage of the admixture is 1%.

[0103] The initial admixture components are water-reducing mother liquor: slump-keeping mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 250: 0: 0: 0: 0: 0: 750.

[0104] Accordingly, the process of compounding the concrete admixture in this example is as follows:

[0105] Step 1: The concrete is discharged from the machine, and the slump is 210 mm. Within 10 minutes, the slump is not lost.

[0106] Step 2: The concrete is discharged from the machine for 30 minutes, and the slump is lost to 140 mm. 20 kg of sodium gluconate is added, and the concrete is discharged from the machine for 15 minutes. The paste and stone are separated. 10 kg of sodium tripolyphosphate and 10 kg of sodium hexametaphosphate are added, and the concrete is discharged from the machine for 30 minutes, and the slump is not lost.

[0107] Step 3: According to the admixture compounding formula of water-reducing mother liquor: slump-keeping mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 250: 0: 0: 10: 10: 0: 730, the admixture is compounded, and the concrete is discharged from the machine for one hour, and the slump is 160 mm. 60 kg of slump-keeping mother liquor is added, and the slump is 180 mm after one hour. 80 kg of slump-keeping mother liquor is added, and the slump is 200 mm after one hour. Therefore, the dosage of the slump-keeping mother liquor is 90 kg.

[0108] Step 4: According to the admixture compounding formula of water-reducing mother liquor: slump-keeping mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 250: 90: 0: 10: 10: 0: 640, the admixture is compounded, and the concrete is discharged from the machine for two hours, and the slump is 210 mm. No further adjustment of the admixture is needed.

[0109] Accordingly, the admixture formula for the C30 concrete obtained in this example is water-reducing mother liquor: slump-keeping mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 250: 90: 0: 10: 10: 0: 640.

[0110] The scheme of the present application is further illustrated by the following comparative examples.

[0111] Comparative Example 1:

[0112] The example 1-1 and the example 1-2 given in the comparative example 1 are comparative schemes of the admixture formula design under normal conditions of raw materials.

[0113] Example 1-1:

[0114] The mix proportion of a certain C30 concrete is cement: fly ash: sand: gravel: water = 267: 101 : 817: 1053: 149. The designed slump is 200 ± 20 mm. The designed dosage of admixture is 1%.

[0115] The initial admixture components are water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: water = 200: 0: 0: 0: 0: 0: 800.

[0116] Step 1, the concrete is discharged from the machine, the slump is 210 mm, within 10 minutes, the slump is not lost.

[0117] Step 2, the concrete is discharged from the machine for 30 minutes, the slump is lost to 140 mm. Add 10 kg of sodium gluconate, discharge from the machine for 30 minutes, the slump is lost to 170 mm. The dosage of sodium gluconate is 10 + (210 - 170) / [(170 - 140) / 10] = 23 kg.

[0118] Step 3, according to the admixture formula of water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: water = 200: 0: 23: 0: 0: 0: 777, mix the concrete and discharge from the machine for one hour, the slump is 160 mm. Add 60 kg of slump retaining mother liquor, the slump is 180 mm after one hour, add 80 kg of slump retaining mother liquor, the slump is 200 mm after one hour. Therefore, the dosage of slump retaining mother liquor is 90 kg.

[0119] Step 4, according to the admixture formula of water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: water = 200: 90: 23: 0: 0: 0: 800, mix the concrete and discharge from the machine for two hours, the slump is 210 mm. No further adjustment of the admixture is needed.

[0120] The admixture formula for the C30 concrete is water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: water = 200: 90: 23: 0: 0: 0: 687.

[0121] Example 1-2:

[0122] The mix proportion of a certain C30 concrete is cement: fly ash: sand: gravel: water = 267: 101 : 817: 1053: 149. The designed slump is 200 ± 20 mm. The designed dosage of admixture is 1%.

[0123] Using the common admixture compounding method in the current market, the formula design process is as follows:

[0124] The initial admixture components are, water-reducing mother liquor: slump-retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: water = 200: 200: 0: 0: 0: 0: 600.

[0125] Step 1, concrete out of machine, slump 210mm.

[0126] Step 2, concrete out of machine 1 hour, slump loss.

[0127] Step 3, concrete out of machine 2 hours, slump loss.

[0128] Determine the admixture formula, water-reducing mother liquor: slump-retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: water = 200: 200: 0: 0: 0: 0: 800.

[0129] See Table 1 for specific comparison:

[0130] Table 1

[0131] Serial number Water-reducing amount Slump-retaining amount Sodium gluconate Water Total amount of admixture solutes 1-1 200 90 23 687 313 1-2 200 200 0 600 400

[0132] As shown in Table 1, the total amount of solute in the admixture prepared by the method of the present application is less than 20% than the general market method. The use amount of functional solute of the admixture is reduced, on the one hand, the cost is saved by more than 20%, on the other hand, the durability of the concrete is less affected.

[0133] Comparative case 2:

[0134] This case 2 is an admixture compounding case under the condition that the sand and stone material contains a large amount of mud, and sodium metabisulfite is added on the basis of case 1.

[0135] Example 2-1.

[0136] The mixing ratio of a certain C25 concrete is cement: fly ash: sand: gravel: water = 222: 100: 852: 1075: 152. The designed slump is 200±20mm. The designed dosage of admixture is 1%.

[0137] The initial admixture components are, water-reducing mother liquor: slump-retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: water = 180: 0: 0: 0: 0: 0: 820.

[0138] Step 1, concrete out of machine, slump 210mm, within 10 minutes, slump loss to 90mm. Add 30kg sodium metabisulfite, concrete out of machine, slump 215mm, no slump loss after 10 minutes.

[0139] Step 2, according to the water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 180: 0: 0: 0: 0: 30: 790. Mix the concrete out of the machine for 30 minutes, and the slump loss is to 140 mm. Add 20 kg of sodium gluconate, and the concrete out of the machine for 30 minutes, and the slump loss is to 180 mm. The dosage of sodium gluconate is 20 + (210-180) / [(180-140) / 10] = 27.5 kg.

[0140] Step 3, according to the water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 180: 0: 27.5: 0: 0: 30: 762.5, add admixtures, mix the concrete out of the machine for one hour, and the slump is 160 mm. Add 60 kg of slump retaining mother liquor, and the one hour slump is 180 mm. Add 80 kg of slump retaining mother liquor, and the one hour slump is 200 mm. Then the dosage of slump retaining mother liquor is 90 kg.

[0141] Step 4, according to the water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 180: 90: 27.5: 0: 0: 30: 672.5, add admixtures, mix the concrete out of the machine for two hours, and the slump is 190 mm. Then the dosage of slump retaining agent is adjusted to 100 kg.

[0142] The admixture formula for the C30 concrete is obtained, water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 180: 100: 27.5: 0: 0: 30: 662.5.

[0143] Example 2-2.

[0144] The mixing proportion of a certain C25 concrete is cement: fly ash: sand: gravel: water = 222: 100: 852: 1075: 152. The designed slump is 200 ± 20 mm. The designed dosage of admixture is 1%.

[0145] The initial admixture components are water reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 200: 200: 0: 0: 0: 0: 600.

[0146] Step 1, the concrete out of the machine, the slump is 210 mm, and the slump loss is to 90 mm within 10 minutes. Add 100 kg of slump retaining agent, and the concrete out of the machine, the slump is 215 mm, and the slump loss is not lost after 10 minutes.

[0147] Step 2, mix the concrete out of the machine for 1 hour, and the slump loss is to 180 mm. Add 30 kg of sodium gluconate, and there is no loss for 1 hour.

[0148] Step 3, the concrete 2 hours slump loss to 200 mm, basically in line with the requirements.

[0149] The admixture formula for the C30 concrete is obtained, and the water-reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 200: 300: 30: 0: 0: 0: 470.

[0150] Specific comparison, see Table 2:

[0151] Table 2

[0152] Serial number Water-reducing amount Slump-retaining amount Sodium gluconate Sodium metabisulfite Water Total amount of admixture solutes 2-1 180 100 27.5 30 662.5 337.5 2-2 200 300 0 0 0 500

[0153] As shown in Table 2, compared with the conventional method, the cost of admixture materials is reduced by more than 30%. And the idea is clear, the means is accurate. In the case of large adsorbability of concrete sand and gravel to admixture, if the slurry extraction measure of the present method is not used, the amount of slump retaining mother liquor will increase sharply.

[0154] Comparative case 3:

[0155] In the comparative case 3, through specific examples 3-1 and 3-2, the admixture formula design comparison is carried out under the condition of cement lacking sulfur. Based on the comparative case, it can be determined that if the stage judgment method given by the present application is not used, the determination of the cement lacking sulfur will be difficult, and the admixture formula design is also carried out by the cumulative method, which will result in a great production cost. Specifically,

[0156] Case 3-1.

[0157] The mixing ratio of a C35 concrete is cement: fly ash: sand: gravel: water = 290: 102: 793: 1055: 150. The designed slump is 200 ± 20 mm. The admixture design dosage is 1%.

[0158] The initial admixture components are water-reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 250: 0: 0: 0: 0: 0: 750.

[0159] Step 1, the concrete is discharged from the machine, and the slump is 210 mm. Within 10 minutes, the slump is not lost.

[0160] Step 2, the concrete is discharged from the machine for 30 minutes, and the slump is lost to 140 mm. 20 kg of sodium gluconate is added, and the concrete is discharged from the machine for 15 minutes, the bottom is grabbed, and the slurry and stone are separated. 10 kg of sodium tripolyphosphate and 10 kg of sodium hexametaphosphate are added, and the concrete is discharged from the machine for 30 minutes, and the slump is not lost.

[0161] Step 3, according to the water-reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 250: 0: 0: 10: 10: 0: 730, admixing admixtures, mixing concrete out of the machine for one hour, the slump is 160 mm. Add 60 kg of slump retaining mother liquor, the one-hour slump is 180 mm, add 80 kg of slump retaining mother liquor, the one-hour slump is 200 mm. Then the amount of slump retaining mother liquor is 90 kg.

[0162] Step 4, according to the water-reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 250: 90: 0: 10: 10: 0: 640 admixing admixtures, mixing concrete out of the machine for two hours, the slump is 210 mm. No further adjustment of admixtures is needed.

[0163] The admixture formula for this C30 concrete is obtained, water-reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 250: 90: 0: 10: 10: 0: 640.

[0164] Case 3-2.

[0165] A C35 concrete mix proportion is cement: fly ash: sand: gravel: water = 290: 102: 793: 1055: 150. The designed slump is 200 ± 20 mm. The designed admixture dosage is 1%.

[0166] Using the common admixture compounding method in the current market, the formula design process is as follows:

[0167] The initial admixture components are water-reducing mother liquor: slump retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium pyrosulfite: water = 250: 250: 0: 0: 0: 0: 500.

[0168] Step 1, concrete out of the machine, the slump is 210 mm, within 10 minutes, the slump loss is to 90 mm. Keep the water-reducing mother liquor unchanged, increase the slump retaining mother liquor to 300 kg. The slump loss is not improved. Increase the sodium gluconate to 30 kg. The slump loss is intensified, the slump is 0 within 10 minutes out of the machine.

[0169] Step 2, using the thickening method. Increase sodium thiosulfate and sodium pyrosulfite by 20 kg each. The out-of-machine slump reaches 220 mm, the 15-minute slump loss is to 60 mm, and the concrete is severely grabbed.

[0170] Step 3, increase the dispersant. Increase sodium tripolyphosphate and sodium hexametaphosphate by 20 kg each. The concrete loss is 0 over time. The 2-hour slump is 180 mm.

[0171] Step 4, increase sodium tripolyphosphate, ammonium hexametaphosphate to 30 kg each, reduce sodium gluconate to 20 kg. The concrete loss is 0.2 hours. The slump is 180 mm.

[0172] The admixture formula for the C30 concrete is obtained, and the water-reducing mother liquor: slump-retaining mother liquor: sodium gluconate: sodium tripolyphosphate: sodium hexametaphosphate: sodium metabisulfite: sodium thiosulfate: water = 250: 300: 20: 30: 30: 20: 20: 330.

[0173] Specific comparison, see Table 3:

[0174] Table 3

[0175]

[0176] As shown in Table 3, the method provided by the application reduces the cost of admixture materials by more than 46% compared with the conventional method, and the idea is clear and the means is precise.

[0177] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A method for compounding a high slump retention high fluidity concrete admixture, characterized in that, The method uses the following four sub-steps to complete the compounding of the admixture according to the performance state changes in the concrete production: (1) The concrete out-machine state adjustment stage; The poly-carboxylic acid water-reducing agent mother liquor and sodium metabisulfite are used to adjust the concrete out-machine state, and the poly-carboxylic acid water-reducing agent mother liquor and sodium metabisulfite dosages are determined; when the out-machine concrete slump does not reach T, the poly-carboxylic acid water-reducing agent mother liquor dosage is first increased according to the proportion, and the poly-carboxylic acid water-reducing agent mother liquor dosage is specifically increased according to the following formula: water-reducing agent mother liquor dosage = (T / actual measured slump) * original water-reducing agent mother liquor dosage; when the out-machine concrete slump reaches T, but 5-10 minutes after the out-machine, the concrete has a serious grabbing bottom and the slump loss reaches 40% or more, the sodium metabisulfite dosage is increased; the slump T is greater than or equal to 200 mm; (2) The concrete out-machine 30 min slump adjustment stage; The sodium gluconate, sodium tripolyphosphate and sodium hexametaphosphate are used to control the 30 min slump of the concrete, and the sodium gluconate, sodium tripolyphosphate and sodium hexametaphosphate dosages are determined; the admixture obtained by the adjustment in step (1) is used to mix the concrete, and the slump is detected after the concrete is out of the machine and is left for thirty minutes, and the sodium gluconate, sodium tripolyphosphate and sodium hexametaphosphate are added according to the loss; when the sodium gluconate is added, the sodium gluconate a kg is first added tentatively to obtain the 30 min slump t302; the sodium gluconate dosage is determined as A = a + (T-t302) / [(t302-t301) / a], wherein t301 is the 30 min slump of the concrete out of the machine without adding the sodium gluconate; (3) The concrete out-machine one hour state adjustment; The poly-carboxylic acid slump-retaining mother liquor is used to control the loss over time of the concrete, and the poly-carboxylic acid slump-retaining mother liquor dosage is determined; the admixture obtained by the adjustment in step (2) is used to mix the concrete, and the slump is detected after the concrete is out of the machine and is left for one hour, and the poly-carboxylic acid slump-retaining mother liquor dosage is adjusted according to the loss; (4) The concrete out-machine two hours state adjustment; The poly-carboxylic acid slump-retaining mother liquor is used to control the 2 hour slump of the concrete, and the poly-carboxylic acid slump-retaining mother liquor dosage is determined; the admixture obtained by the adjustment in step (3) is used to mix the concrete, and the slump is detected after the concrete is out of the machine and is left for two hours, and the poly-carboxylic acid slump-retaining mother liquor dosage is adjusted according to the loss.

2. The method for compounding high-slump concrete admixture according to claim 1, wherein In step (2) of the compounding method, the sodium gluconate is first added, and the sodium gluconate dosage is determined according to the slump of the concrete left for thirty minutes out of the machine.

3. The method for compounding high slump retention high fluidity concrete admixture according to claim 2, characterized in that, In step (2) of the compounding method, after the sodium gluconate is added, the concrete out of the machine has a serious grabbing bottom and paste-stone separation phenomenon, and then the sodium tripolyphosphate and sodium hexametaphosphate are used; and the sodium tripolyphosphate and sodium hexametaphosphate dosages are determined according to the slump of the concrete left for thirty minutes out of the machine.

4. The method for compounding high slump retention high fluidity concrete admixture according to claim 3, characterized in that, In step (2) of the compounding method, the sodium tripolyphosphate and sodium hexametaphosphate are added according to a 1:1 ratio.

5. The method for compounding superplasticizer for high flowability and high slump retention concrete according to claim 1, wherein The poly-carboxylic acid slump-retaining mother liquor dosage is positively correlated with the glue material dosage.

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