CN111157403B - Method for detecting flocculating agent in sand - Google Patents
Method for detecting flocculating agent in sand Download PDFInfo
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- CN111157403B CN111157403B CN201911336311.4A CN201911336311A CN111157403B CN 111157403 B CN111157403 B CN 111157403B CN 201911336311 A CN201911336311 A CN 201911336311A CN 111157403 B CN111157403 B CN 111157403B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N11/00—Investigating flow properties of materials, e.g. viscosity, plasticity; Analysing materials by determining flow properties
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/38—Concrete; ceramics; glass; bricks
- G01N33/383—Concrete, cement
Abstract
The invention discloses a method for detecting a flocculating agent in sand, which comprises the following steps: drying sand to be detected, and then sieving to remove broken stone; adding water into the sieved sand, stirring to homogenize, and standing to obtain a supernatant; stirring and mixing cement and water uniformly to obtain cement paste, and measuring the viscosity of the cement paste to obtain t1(ii) a Stirring and mixing the cement and the supernatant liquid uniformly to obtain cement paste, and measuring the viscosity of the cement paste to obtain t2；t3＝t2‑t1When t is3When the content of the flocculant in the sand to be detected is larger than the set value, the content of the flocculant in the sand to be detected is unqualified; when t is3And when the content of the flocculant in the sand to be detected is less than or equal to the set value, the content of the flocculant in the sand to be detected is qualified. The lower limit of the content of the flocculant in the machine-made sand for the building measured by the method is high, and the flocculant still has sensitivity to the flocculant with the concentration of four ten-thousandth in the sand; selecting t according to the concrete slump requirement3Different set values, based on the measured t3And judging whether the content of the flocculant in the machine-made sand to be detected is qualified or not, and quickly judging whether the content of the flocculant in the machine-made sand under different use conditions is qualified or not.
Description
Technical Field
The invention relates to the technical field of building materials, in particular to a method for detecting a flocculating agent in sand and content of the flocculating agent.
Background
Sand, which typically accounts for 30% and more of the volume of the concrete, is an important raw material component of concrete. As river sand mining is limited, machine-made sand made from crushed stone is brought to the market on a large scale. The machine-made sand raw material stone is usually mixed with pug and needs to be washed by water to remove the pug, and because of the requirement of environmental protection, the water used in the machine-made sand yard can not be discharged and needs to be recycled, so that the water formed by production is usually treated by flocculating agents such as polyacrylamide and the like, so that the water can be clarified and recycled in a sedimentation tank, and in the process of washing the machine-made sand to remove the pug by circulating water in the machine-made sand yard, the flocculating agents in the circulating water exist in the machine-made sand in the form of water solution or mud absorbed in the sand, and the water content and the mud content of the machine-made sand are higher, so that the machine-made sand produced in the machine-made sand yard contains more flocculating agent components.
The flocculating agents such as polyacrylamide have extremely obvious influence on concrete, and as a water-soluble high polymer, the polyacrylamide molecular chain has a bridging effect and the charge effect of an anionic group, when the polyacrylamide is dissolved in water, not only the coil-shaped macromolecular structure of the polyacrylamide is changed into a curve shape, the viscosity of the solution is increased, but also the polyacrylamide can be dissociated into ions with multiple charges and large molecular weight, the ionization balance of a water body is broken, and the cement colloid particles are flocculated. Tests show that the expansion degree of the mortar can be reduced from 310mm to 260mm by mixing three-ten-thousandth mass of the polyacrylamide into the concrete cementing material, and the flow property of cement slurry is seriously influenced. Therefore, if the building sand contains a certain flocculating agent component, the flow performance of the produced concrete is greatly influenced. The working performance is an important factor for measuring commercial concrete, and not only influences the working state and the pumping performance of the concrete, but also influences the construction difficulty of the concrete. Therefore, the commercial concrete mixing plant strictly controls the flowing performance of concrete, and if the sand contains flocculating agent components, the commercial concrete mixing plant brings difficulty in controlling the working performance of the concrete, and simultaneously increases the difficulty of pumping and construction, thereby causing hidden troubles of pipe blockage and pipe explosion quality problems.
At the present stage, the flocculating agent of the building sand is below one thousandth of the concentration of water, mainly exists in mud and water in the sand, general chemical analysis is difficult to detect due to extremely low concentration and interference of other factors, and if sand containing the flocculating agent and clean sand are used for simultaneously carrying out trial test, the working performance of concrete is compared, so that the content of the flocculating agent in the building sand and a method for measuring the influence of the flocculating agent have larger errors; on the other hand, the experimental result is also very easily influenced by the operation technique and skill level of an operator, and the direct judgment of the working performance of the added mixture cannot judge whether the used sand contains the flocculating agent and the influence degree of the flocculating agent on the mixture, so that the quality of the purchased sand is difficult to judge by a commercial concrete mixing plant, and the condition of the flocculating agent of the purchased sand is limited to control the quality of the commercial concrete.
Disclosure of Invention
The invention aims to provide a method for detecting a flocculating agent in sand, which can simply, accurately and quickly detect the content of the flocculating agent in the sand and measure the influence degree of the flocculating agent on the working performance of concrete.
The technical scheme adopted by the invention for solving the technical problems is as follows: a method for detecting a flocculating agent in sand comprises the following steps:
(1) drying the sand to be detected, and then sieving to remove broken stones;
(2) adding water into the sieved sand, stirring to homogenize, and standing to obtain a supernatant; the mass ratio of the sand to the water is 1: 1;
(3) uniformly stirring and mixing the cement and the water according to the mass ratio of 2: 1 to obtain the cement paste, and measuring the viscosity of the cement paste to obtain t1；
(4) Uniformly stirring and mixing the cement and the supernatant obtained in the step (2) according to the mass ratio of 2: 1 to obtain the cement paste, and measuring the viscosity of the cement paste to obtain t2；
(5)t3＝t2-t1When t is3When the content of the flocculant in the sand to be detected is larger than the set value, the content of the flocculant in the sand to be detected is unqualified; when t is3And when the content of the flocculant in the sand to be detected is less than or equal to the set value, the content of the flocculant in the sand to be detected is qualified.
Further, in the step (1), the sand to be detected is dried until the water content is lower than 0.5%, and the drying temperature is less than or equal to 40 ℃.
Further, in the step (2), the dried sand is sieved by a 4.75mm sieve, and broken stones in the sand are removed.
Further, the stirring in the step (2) adopts a cement paste stirrer, and the stirring is carried out for 5-10min in a rapid stirring mode.
And (3) further, stirring water and cement in the cement paste stirrer in a slow stirring mode for 2-5min, taking out the stirring pot, uniformly scraping the cement paste by using a scraper, then reinstalling the stirring pot into the stirrer, and stirring for 3-6min in a rapid stirring mode.
Further, the step (3) adopts a mud viscometer to measure the viscosity of the obtained cement paste, and the average value t is obtained by measuring three times1。
And (3) further, stirring the supernatant and the cement in a cement paste stirrer in a slow stirring mode for 2-5min, taking out the stirring pot, uniformly scraping the cement paste by using a scraper, then reinstalling the stirring pot into the stirrer, and stirring for 3-6min in a rapid stirring mode. Namely, the mixing time of the supernatant and the cement is the same as the mixing time of the water and the cement.
Further, in the step (4), the viscosity of the obtained cement paste is measured by a mud viscometer, and the average value t is obtained by measuring three times2。
Further, the cements in the steps (2) and (3) are the same reference cement.
Further, the content of the flocculant in the sand to be detected is obtained by the following formula,
y＝4.166E-3*exp(t3/1217.9)-4.157E-3
wherein y is the mass ratio of the flocculating agent to the sand.
The invention has the beneficial effects that: the method is simple to operate, has accurate test results, and can detect the machine-made sand to be adopted at any time in the actual concrete preparation process; the lower limit of the content of the flocculant in the machine-made sand for the building measured by the method is high, and the machine-made sand for the building still has sensitivity to the flocculant with the concentration of four hundred thousandths of sand, thereby solving the problem that the general titration analysis is difficult to detect; selecting t according to the concrete slump requirement3Different set values, based on the measured t3Judging whether the content of the flocculant in the machine-made sand to be detected is qualified or not, quickly judging whether the content of the flocculant in the machine-made sand under different use conditions is qualified or not, and establishing t3The flocculant content in the sand can be quantified by correlating with the numerical value of the flocculant content in the sand.
Drawings
FIG. 1 is a graph of the effect of flocculant content on the delayed cement paste run-out time;
FIG. 2 is a numerical correlation of the delayed cement paste discharge time with the specific gravity of the flocculant in the sand.
Detailed Description
The invention is further illustrated with reference to the following figures and examples.
A method for detecting a flocculating agent in sand comprises the following steps:
(1) drying the sand to be measured until the water content is lower than 0.5 percent and the drying temperature is less than or equal to 40 ℃, and then sieving the sand by a 4.75mm sieve to remove broken stones in the sand;
the sand to be tested is machine-made sand, molecular chain conformation of polyacrylamide water-soluble high molecular compounds commonly existing in the machine-made sand is changed and molecular weight is reduced at a temperature of 75 ℃ or higher, viscosity of a solution formed by dissolving the polyacrylamide water-soluble high molecular compounds in water is reduced, flocculation capacity is changed, and a test result is further influenced, so that a method for slowly drying the sand to be tested at a lower temperature is adopted, the water content in the sand to be tested is controlled to be lower than 0.5%, the main body of the sand to be tested under the test procedure is sand and partial stone powder and mud, the water content is lower than 0.5%, and the phenomenon of poor repeatability caused by test result deviation formed by water content difference is avoided; according to the standard requirements of GB/T14684 plus 2011 building sand, the particle size of the building sand is not more than 4.75mm, so the sand to be detected is screened, and in addition, the flocculant adsorbed by the building sand is influenced by the mud content and the specific surface area, so that the content fluctuation of the flocculant in the sand to be detected is avoided, and the particle component with the particle size of more than 4.75mm is removed, wherein the large particles which have great influence on the specific surface area of the sand possibly exist in the sand to be detected.
(2) Adding water into the sieved sand, stirring for 5-10min in a rapid stirring mode by using a cement paste stirrer, stirring to a homogeneous state, and standing to obtain a supernatant; the mass ratio of the sand to the water is 1: 1;
the flocculant used in the machine-made sand is a water-soluble polymeric flocculant which is soluble in water, so that the flocculant can be partially dissolved in supernatant liquid after being stirred.
(3) Preparing materials of cement and water according to the mass ratio of 2: 1, stirring the water and the cement in a cement paste stirrer for 2-5min in a slow stirring mode, taking out a stirring pot, uniformly scraping the cement paste by a scraper, then installing the cement paste into the stirrer again, stirring for 3-6min in a fast stirring mode to obtain the cement paste, measuring the viscosity of the obtained cement paste by using a slurry viscometer, measuring the viscosity of the obtained cement paste for three times, and taking the average value t1。
(4) Mixing cement with the steps(2) Preparing materials of the obtained supernatant according to the mass ratio of 2: 1, firstly stirring the supernatant and cement in a cement paste stirrer for 2-5min in a slow stirring mode, taking out a stirring pot, uniformly scraping the cement paste by a scraper, then installing the cement paste into the stirrer again, stirring for 3-6min in a fast stirring mode, measuring the viscosity of the obtained cement paste by using a slurry viscometer, measuring three times, and taking the average value t2(ii) a The cement in the steps (2) and (3) is reference cement;
the used slurry viscometer is funnel-shaped, the outflow pipe diameter is 4.75mm, the pipe length is 100mm, and the capacity is 500 ml; the slurry viscosity meter is a funnel-shaped instrument, and the liquid viscosity is measured by measuring the outflow time of liquid in the funnel from an outflow pipe orifice, so that the instrument is low in price, wide in source, light, convenient and fast, and is beneficial to the use of the test method in a commercial concrete mixing plant;
the stirrer is a universal cement paste stirrer, the revolution stirring speed is 140 +/-5 r/min and the rotation stirring speed is 62 +/-3 r/min in a slow stirring mode, the revolution stirring speed is 285 +/-5 r/min and the rotation stirring speed is 120 +/-5 r/min in a rapid stirring mode;
in order to reduce errors of test results caused by different instruments, the clear water flowing out for 15 +/-0.5 seconds is taken as the qualified standard of the instrument, if the clear water flowing out is unqualified, the outflow port is cleaned and checked, and the test result is not qualified again, the slurry viscometer needs to be replaced; the subsequent test of the outflow time of the cement paste is more accurate;
the concrete steps of measuring the viscosity of the cement paste by using a mud viscometer are as follows: quickly taking 500ml of stirred cement paste by using a measuring cup, then injecting the cement paste into a vertical slurry viscometer, simultaneously blocking an outlet of the viscometer by using a finger, after the 500ml of the paste is poured into the viscometer, placing the measuring cup below the outlet of the viscometer, releasing the blocked outlet of the viscometer by using the finger, starting a stopwatch to time, observing the state in the viscometer, stopping the time counting when the paste completely flows out, performing the operation for three times, and taking an average value to obtain the outflow time of the cement paste from the funnel-shaped viscometer, namely the viscosity of the cement paste;
the used cement is reference cement, the proportion of water to cement is 0.5, the volume of the mixed slurry is more than 500ml, the mineral components of the reference cement are tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite and gypsum, no mixed material is added, the components are fixed, the test result is more accurate, and the repeatability is strong; the proportion of water and cement is fixed, and the outflow time of the cement paste body mixed by clear water and cement is fixed, so that the outflow time and the viscosity of the sand leaching solution mixed by cement can be conveniently measured, and the influence of flocculation components in sand on the fluidity of the cement paste body can be quantified; the purpose of stirring twice is that the rotating blades of the stirrer can not completely stir the cement sinking at the bottom of the stirring pot, the stirring pot is taken out, the bottom cement is hung by a scraper, and the cement paste can be stirred more uniformly by stirring again; in addition, the flocculation micelle in the cement paste can be opened by stirring in a quick mode, so that the outlet blockage caused in the test is prevented, and the test error is reduced;
after the cement paste is stirred, the paste needs to be injected into a mud flow meter within 15 seconds, the test operation is started, and the deviation of the results of three tests is not more than 5%;
after the supernatant and the cement paste are mixed, because the curve-shaped molecules of the flocculating agent contained in the supernatant not only increase the viscosity of the solution, but also dissociate into multi-charge high molecular weight ions to break the ionization balance of the paste and enable the cement gel to flocculate, which is also the reason that the building sand containing the flocculating component influences the working performance of the mixed concrete, the testing method eliminates other interference factors, only selects two components which interact with each other in the concrete, and the flocculating agent and the cement in the supernatant are mixed to measure the interaction degree of the two through the flowing performance of the paste formed by mixing the two, and the flowing performance of the cement paste is quantified and determined by adopting the outflow time, thereby being convenient for determining the influence degree of the flocculating agent in the building sand on the working performance of the concrete.
(5)t3＝t2-t1When t is3When the content of the flocculant in the sand to be detected is larger than the set value, the content of the flocculant in the sand to be detected is unqualified; when t is3When the content of the flocculant in the sand to be detected is less than or equal to a set value, the content of the flocculant in the sand to be detected is qualified;
in the present detection method, t3＝t2-t1The difference in viscosity between the neat cement paste prepared for the supernatant and the neat cement paste prepared with the clear water is also the delayed outflow time, t, of the slurry prepared from 500ml of the supernatant of the machine-made sand for construction relative to the neat cement paste prepared with the clear water3Has high correlation with slump loss of concrete prepared from the machine-made sand, and delays the outflow time t through multiple tests3About 20mm slump loss of the C30 concrete of the tested initial 200mm slump caused by 32 seconds, so the outflow time t is delayed3When the time is more than 32 seconds, the flocculating component contained in the building sand is too much, the influence on the working performance of concrete is too great, and the building sand is unqualified sand;
the delayed outflow time of the cement neat paste prepared by the machine-made sand supernatant to be tested compared with the cement neat paste prepared by clean water is obviously related to the slump loss of the concrete compounded by the sand containing the flocculant (compared with the concrete compounded by clean sand), because the reasons of the reduction of the fluidity of the mixture caused by the two are flocculation components in the sand to be tested; thus, the slump test of C30 concrete and the soak solution outflow time delay time test were carried out using different sands containing flocculants, and the correlation between the delay time of soaking and the slump loss of the compounded concrete was measured; the slump test is carried out according to GB/T50080-2016 Standard test method for common concrete mixtures, the C30 concrete is prepared from cement, water, mineral powder, fine aggregate, coarse aggregate 301, 165, 53, 877, 1052 and a high-performance polycarboxylic acid water reducer in an amount of 1.5%, and the slump of the clean sand concrete is 200 mm. The variable is controlled by adopting a method of externally doping the flocculant in the clean sand, so that other characteristics of the sand containing the flocculant are the same as those of the clean sand, and after multiple tests, when the slump loss of the C30 concrete prepared by the sand containing the flocculant is 20mm, the delayed outflow time of the clean slurry prepared by a corresponding soaking solution is about 32 seconds, so that when the delayed outflow time of the machine-made sand to be tested in the test program is more than 32 seconds, the slump loss of the C30 concrete caused by the sand to be tested is more than 20mm, the influence on the working performance of the concrete is large, the sand is unqualified, a commercial concrete mixing plant can be screened, the sand is not received for production, when the slump loss is less than 20mm, the machine-made sand to be tested has less influence on the working performance of the concrete, and the machine-made sand can be received for production as appropriate.
Dissolving a polyacrylamide flocculant commonly used in a machine-made sand field in water to prepare cement paste for parallel test, wherein when the delayed outflow time of a flocculant solution and a sand soaking solution under the test program is equal, the flocculation component contents of the flocculant solution and the sand soaking solution are equal; the influence of the flocculant on the delayed outflow time of the clean slurry is shown in fig. 1, and as can be seen from fig. 1, the delayed outflow time of the test method is very sensitive to the content of the flocculant in the sand, the delayed outflow time (about 20 seconds) can be still measured for a solution containing four ten-thousandths of sand, and the delayed outflow time of a flocculant simulation solution with two-ten-thousandths of sand quality is increased to about 50 seconds, so that the test flow has high sensitivity and is still effective for extremely low content of flocculant components; in order to quantify the content of the flocculant in the sand, a plurality of tests are carried out on the basis of preparing a simulated sand soaking solution by dissolving a polyacrylamide solution in water, the delayed outflow time and the flocculant in the sand are plotted as shown in fig. 2, and a numerical correlation is established, wherein the relationship between the delayed outflow time and the specific gravity of the flocculant in the sand is that y-4.166E-3·exp(t3/1217.9)-4.157E-3，R2The correlation between the two values indicates that the formula can well react, so that the specific gravity of the flocculant contained in the sand can be reversely deduced according to the delayed outflow time of the cement paste prepared from the manufactured sand supernatant according to the formula.
The content of the flocculant in the sand to be measured is obtained by the following formula,
y＝4.166E-3·exp(t3/1217.9)-4.157E-3
wherein y is the mass ratio of the flocculating agent to the sand, and E-3Is 1 × 10-3。
Example 1:
s1: drying the sand manufactured by the sand field machine at 40 ℃ to ensure that the water content is lower than 0.5%;
s2: sieving the dried sand sample by a 4.75mm sieve to remove broken stones in the sand;
s3: taking about 1kg of sieved sand, putting the sieved sand into a stirring pot on a cement paste mixer, then adding 1kg of water, installing the stirring pot into a backwater cement paste mixer, turning on a power supply of the mixer, stirring for 5min in a rapid stirring mode, then taking down the stirring pot, putting the stirring pot on a horizontal table, standing for 1h, and taking supernatant for later use;
s4: taking a funnel-shaped slurry viscometer, washing the slurry viscometer and a measuring cup with water, and then carrying out detection operation;
s5: the slurry viscometer is vertical, 500ml clear water is injected into the viscometer by using a measuring cup, the outflow port of the viscometer is blocked by fingers so that the clear water does not flow out, the measuring cup is placed below the outflow port, the outflow port of the viscometer is blocked by releasing the fingers, the stopwatch timing is started, the internal state of the viscometer is observed, when the water completely flows out, the timing is stopped, the outflow time is 15.3 seconds, the slurry viscometer is qualified, and the next step of testing can be carried out;
s6: weighing 1kg of reference cement, putting the reference cement into a cement paste stirring pot, adding 500g of water into the stirring pot filled with the cement, starting a stirrer, stirring for 2min in a slow stirring mode, taking out the stirring pot, scraping cement paste uniformly by a scraper, then reinstalling the stirring pot into the stirrer, and stirring for 3min in a rapid stirring mode.
S7: after stirring, taking 500ml of slurry in a stirring pot, injecting the slurry into a vertical slurry viscometer, simultaneously blocking an outlet of the viscometer by fingers, after 500ml of slurry is poured into the viscometer, placing a measuring cup below the outlet of the viscometer, releasing the blocked outlet of the viscometer by the fingers, starting stopwatch timing at the same time, observing the state in the viscometer, stopping timing when the slurry completely flows out, performing the operation for three times, wherein the three measurement results are 120 seconds, 116 seconds and 117 seconds respectively, and taking an average value to obtain the outflow time of pure water mixed pure slurry from a funnel-shaped viscometer to be 117.7 seconds, thereby obtaining the viscosity t of the cement pure slurry1117.7;
s8: cleaning the viscometer and a cone, weighing 1kg of reference cement and 500g S3 supernatant, repeating the operations S6 and S7 for three times, wherein the three times are respectively 178 seconds, 181 seconds and 177 seconds, averaging to obtain the outflow time of the pure cement slurry mixed with the supernatant water from the funnel-shaped viscometer, which is 178.6 seconds, and obtaining the viscosity t of the pure cement slurry2178.6;
s9: the delayed outflow time caused by the sand leaching solution is t3Is 61.7 secondsIf the specific gravity of the flocculating agent in the sand is more than 32 seconds, calculated by the formula (1)E-4The sand has a large influence on the fluidity of the mixed concrete, and is judged to be unqualified, and the commercial concrete mixing plant cannot be purchased.
The accuracy of the concrete trial-mix verification test method is respectively carried out by adopting the sand-yard machine-made sand and the clean sand without flocculant, the concrete with the label of C30 is trial-mixed, the concrete is tested for slump after being uniformly mixed, the weight ratio of cement to water is that mineral powder to sand is that coarse aggregate is 301: 165: 53: 877: 1052, the mixing amount of the high-performance polycarboxylic acid water reducing agent is 1.5%, the cement is P.O 42.5 grade cement, the mineral powder is S95 grade mineral powder, the sand is medium coarse sand and the coarse aggregate is 5-31.5mm macadam; through detection, the slump of the concrete prepared from the clean sand is 200mm, the slump of the concrete prepared from the sand yard machine-made sand is 175mm, the influence degree of the sand on the working performance of the concrete is large, the sand is indeed unqualified machine-made sand, a commercial concrete mixing plant cannot be purchased, and the test method is accurate.
Example 2:
s1: drying the sand manufactured by the sand field machine at 40 ℃ to ensure that the water content is lower than 0.5%;
s2: sieving the dried sand sample by a 4.75mm sieve to remove broken stones in the sand;
s3: taking about 1kg of sieved sand, putting the sieved sand into a stirring pot on a cement paste mixer, then adding 1kg of water, installing the stirring pot into a backwater cement paste mixer, turning on a power supply of the mixer, stirring for 5min in a rapid stirring mode, then taking down the stirring pot, putting the stirring pot on a horizontal table, standing for 1h, and taking supernatant for later use;
s4: taking a funnel-shaped slurry viscometer, washing the slurry viscometer and a measuring cup with water, and then carrying out detection operation;
s5: the slurry viscometer is erected, 500ml of clean water is injected into the viscometer by using a measuring cup, the outflow port of the viscometer is blocked by fingers so that the clean water does not flow out, the measuring cup is placed below the outflow port, the fingers are released to block the outflow port of the viscometer, the stopwatch timing is started, the internal state of the viscometer is observed, when the water completely flows out, the timing is stopped, the outflow time is 16 seconds, the slurry viscometer is unqualified, after the outflow pipe of the viscometer is cleaned, the operation is repeated, the flow time is 15.2 seconds, the slurry viscometer is qualified, and the next step of testing can be carried out;
s6: weighing 1kg of reference cement, putting the reference cement into a stirring pot of a cement paste stirring machine, adding 500g of water into the stirring pot filled with the cement, starting the stirring machine, stirring for 2min in a slow stirring mode, taking out the stirring pot, scraping cement paste uniformly by a scraper, then reinstalling the stirring pot into the stirring machine, and stirring for 3min in a rapid stirring mode.
S7: after stirring, taking 500ml of slurry in a stirring pot, injecting the slurry into a vertical slurry viscometer, simultaneously blocking an outlet of the viscometer by fingers, after 500ml of slurry is poured into the viscometer, placing a measuring cup below the outlet of the viscometer, releasing the blocked outlet of the viscometer by the fingers, simultaneously starting stopwatch timing, observing the state in the viscometer, stopping timing when the slurry completely flows out, performing the operation for three times, wherein the measurement results of the three times are respectively 115.4 seconds, 114.8 seconds and 116.3 seconds, and the outflow time of pure water-mixed pure slurry from a funnel-shaped viscometer is 115.5 seconds by taking an average value, namely measuring the viscosity t of the slurry1Is 115.5;
s8: cleaning viscometer and cone, weighing 1kg of reference cement and 500g S3 supernatant, repeating S6 and S7 for three times, wherein the three times are 142.3 seconds, 139.8 seconds and 144.2 seconds respectively, and averaging to obtain the outflow time t of the pure slurry mixed with sand leaching solution supernatant from funnel-shaped viscometer2142.1 seconds, i.e., the slurry viscosity t2142.1;
s9: the delayed outflow time caused by the supernatant of the sand leaching solution is t326.6 seconds and less than 32 seconds, and the specific gravity of the flocculating agent in the sand is 1E calculated by the formula (1)-4The sand has little influence on the fluidity of the mixed concrete, and can be purchased in commercial concrete mixing plants.
The accuracy of the concrete trial-mix verification test method is respectively carried out by adopting the sand-yard machine-made sand and the clean sand without flocculant, the concrete with the label of C30 is trial-mixed, the concrete is tested for slump after being uniformly mixed, the weight ratio of cement to water is that mineral powder to sand is that coarse aggregate is 301: 165: 53: 877: 1052, the mixing amount of the high-performance polycarboxylic acid water reducing agent is 1.5%, the cement is P.O 42.5 grade cement, the mineral powder is S95 grade mineral powder, the sand is medium coarse sand and the coarse aggregate is 5-31.5mm macadam; through the detection, the slump of the concrete prepared from the clean sand is 200mm, the slump of the concrete prepared from the sand yard machine-made sand is 190mm, the influence degree of the sand on the working performance of the concrete is small, and the concrete is qualified machine-made sand and can be purchased by a commercial concrete mixing plant.
Example 3:
s1: drying the sand manufactured by the sand field machine at 40 ℃ to ensure that the water content is lower than 0.5%;
s2: sieving the dried sand sample by a 4.75mm sieve to remove broken stones in the sand;
s3: taking about 1kg of sieved sand, putting the sieved sand into a stirring pot on a cement paste mixer, then adding 1kg of water, installing the stirring pot into a backwater cement paste mixer, turning on a power supply of the mixer, stirring for 5min in a rapid stirring mode, then taking down the stirring pot, putting the stirring pot on a horizontal table, standing for 1h, and taking supernatant for later use;
s4: taking a funnel-shaped slurry viscometer, washing the slurry viscometer and a measuring cup with water, and then carrying out detection operation;
s5: the slurry viscometer is erected, 500ml of clean water is injected into the viscometer by using a measuring cup, the outflow port of the viscometer is blocked by fingers so that the clean water does not flow out, the measuring cup is placed below the outflow port, the fingers are released to block the outflow port of the viscometer, the stopwatch timing is started, the internal state of the viscometer is observed, when the water completely flows out, the timing is stopped, the outflow time is 16 seconds, the slurry viscometer is unqualified, after the outflow pipe of the viscometer is cleaned, the operation is repeated, the flow time is 14.8 seconds, the slurry viscometer is qualified, and the next step of testing can be carried out;
s6: weighing 1kg of reference cement, putting the reference cement into a cement paste stirring pot, adding 500g of water into the stirring pot filled with the cement, starting a stirrer, stirring for 2min in a slow stirring mode, taking out the stirring pot, scraping cement paste uniformly by a scraper, then reinstalling the stirring pot into the stirrer, and stirring for 3min in a rapid stirring mode.
S7: after stirring, taking 500ml of slurry in a stirring pot, injecting the slurry into a vertical slurry viscometer,simultaneously using fingers to block the outlet of the viscometer, pouring 500ml of slurry into the viscometer, placing a measuring cup below the outlet of the viscometer, releasing the blocked outlet of the viscometer by fingers, simultaneously starting a stopwatch to time, observing the state in the viscometer, stopping the time measurement when the slurry completely flows out, performing the operation for three times, wherein the three measurement results are respectively 112.1 seconds, 114.2 seconds and 113.5 seconds, and taking the average value to obtain the outflow time of pure water-mixed pure slurry from the funnel-shaped viscometer to be 113.3 seconds, namely measuring the viscosity t of the cement pure slurry1Is 113.3;
s8: cleaning the viscometer and a cone, weighing 1kg of reference cement and 500g S3 supernatant, repeating the operations S6 and S7 for three times, wherein the three times are 253.7 seconds, 253.2 seconds and 252.5 seconds respectively, averaging to obtain the average value, and the outflow time of the clean slurry mixed with the sand leaching solution supernatant from the funnel-shaped viscometer is 253.1 seconds, namely measuring the viscosity t of the cement clean slurry2Is 253.1; (ii) a
S9: the delayed outflow time caused by the supernatant of the sand leaching solution is t3139.8 seconds and more than 32 seconds, and the specific gravity of the flocculant in the sand is 5.16 calculated by the formula (1)E-4The sand has a large influence on the fluidity of the mixed concrete, and is judged to be unqualified, and the commercial concrete mixing plant cannot be purchased.
The accuracy of the concrete trial-mix verification test method is respectively carried out by adopting the sand-yard machine-made sand and the clean sand without flocculant, the concrete with the label of C30 is trial-mixed, the concrete is tested for slump after being uniformly mixed, the weight ratio of cement to water is that mineral powder to sand is that coarse aggregate is 301: 165: 53: 877: 1052, the mixing amount of the high-performance polycarboxylic acid water reducing agent is 1.5%, the cement is P.O 42.5 grade cement, the mineral powder is S95 grade mineral powder, the sand is medium coarse sand and the coarse aggregate is 5-31.5mm macadam; through detection, the slump of the concrete prepared from the clean sand is 200mm, the slump of the concrete prepared from the sand yard machine-made sand of the embodiment is 170mm, the influence degree of the sand on the working performance of the concrete is large, the sand is determined to be unqualified sand, and a commercial concrete mixing plant cannot be purchased.
Claims (9)
1. A method for detecting a flocculating agent in sand is characterized by comprising the following steps: the method comprises the following steps:
(1) drying sand to be detected, and then sieving to remove broken stone;
(2) adding water into the sieved sand, stirring to homogenize, and standing to obtain a supernatant; the mass ratio of the sand to the water is 1: 1;
(3) uniformly stirring and mixing the cement and the water according to the mass ratio of 2: 1 to obtain the cement paste, and measuring the viscosity of the cement paste to obtain t1；
(4) Uniformly stirring and mixing the cement and the supernatant obtained in the step (2) according to the mass ratio of 2: 1 to obtain the pure cement paste, and measuring the viscosity of the pure cement paste to obtain t2；
（5）t3= t2- t1When t is3When the content of the flocculant in the sand to be detected is larger than the set value, the content of the flocculant in the sand to be detected is unqualified; when t is3When the content of the flocculant in the sand to be detected is less than or equal to a set value, the content of the flocculant in the sand to be detected is qualified;
the content of the flocculant in the sand to be measured is obtained by the following formula,
y=4.166E-3·exp(t3/1217.9)-4.157E-3
wherein y is the mass ratio of the flocculating agent to the sand, E-3Is 1 × 10-3。
2. The method for detecting the flocculating agent in the sand according to claim 1, which is characterized in that: and (2) drying the sand to be detected until the water content is lower than 0.5% and the drying temperature is less than or equal to 40 ℃.
3. The method for detecting the flocculating agent in the sand according to claim 1, which is characterized in that: and (2) sieving the dried sand by a 4.75mm sieve to remove broken stones in the sand.
4. The method for detecting the flocculating agent in the sand according to claim 1, which is characterized in that: and (3) stirring in the step (2) by adopting a cement paste stirrer for 5-10min in a rapid stirring mode.
5. The method for detecting the flocculating agent in the sand according to claim 1, which is characterized in that: and (3) firstly stirring water and cement in a cement paste stirrer for 2-5min in a slow stirring mode, taking out the stirring pot, uniformly scraping the cement paste by using a scraper, then reinstalling the stirring pot into the stirrer, and stirring for 3-6min in a rapid stirring mode.
6. The method for detecting the flocculating agent in the sand according to claim 1, which is characterized in that: and (3) measuring the viscosity of the obtained cement paste by adopting a mud viscometer, and taking the average value t in three times of measurement1。
7. The method for detecting the flocculating agent in the sand according to claim 1, which is characterized in that: and (4) firstly stirring the supernatant and the cement in a cement paste mixer for 2-5min in a slow stirring mode, taking out the mixing pot, uniformly scraping the cement paste by using a scraper, then reinstalling the cement paste in the mixer, and stirring for 3-6min in a rapid stirring mode.
8. The method for detecting the flocculating agent in the sand according to claim 1, which is characterized in that: and (4) measuring the viscosity of the obtained cement paste by adopting a mud viscometer, and taking the average value t in three times of measurement2。
9. The method for detecting the flocculating agent in the sand according to claim 1, which is characterized in that: the cement in the steps (2) and (3) is the same reference cement.
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| CN112198302B (en) * | 2020-10-25 | 2022-12-16 | 中铁二局第一工程有限公司 | Method and measuring tool for rapidly detecting mud content of fine aggregate |
| CN113720804B (en) * | 2021-07-29 | 2024-03-26 | 成都宏基建材股份有限公司 | Method for rapidly detecting residual quantity of flocculant in sand for concrete |
| CN114509367B (en) * | 2021-12-31 | 2024-02-09 | 成都宏基建材股份有限公司 | Method for rapidly detecting powder content of sand for concrete |
| CN114994298A (en) * | 2022-05-10 | 2022-09-02 | 中国矿业大学 | Method for detecting residual amount of flocculating agent in machine-made sand |
| CN114965849B (en) * | 2022-05-12 | 2023-08-29 | 江苏奥莱特新材料股份有限公司 | Test powder for judging existence of flocculant in water-washed sand and judging method |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4196614A (en) * | 1978-01-20 | 1980-04-08 | Mclaughlin Robert R | Process and device for quantitative analysis of cement and water content in fresh concrete |
| CN102353616A (en) * | 2011-06-23 | 2012-02-15 | 中国石油天然气股份有限公司 | Intrinsic viscosity number measuring method for polyacrylamide polymers for oil displacement |
| CN102466607A (en) * | 2010-11-15 | 2012-05-23 | 李波 | Method for measuring intrinsic viscosity number of cationic flocculant |
| CN103884626A (en) * | 2014-02-21 | 2014-06-25 | 大连大学 | Method for carrying out quantitative classification and qualitative analysis on flocculating constituent |
| EP2840395A1 (en) * | 2013-08-22 | 2015-02-25 | Savannah River Nuclear Solutions, LLC | Method for characterization of the rate of movement of an oxidation front in cementitious materials |
| CN106977160A (en) * | 2017-05-08 | 2017-07-25 | 天津市滨涛混凝土有限公司 | A kind of non-dispersible underwater concrete and preparation method thereof |
| CN110261265A (en) * | 2019-06-25 | 2019-09-20 | 成都建工赛利混凝土有限公司 | Flocculant detection method and its detection device in a kind of sand |
-
2019
- 2019-12-23 CN CN201911336311.4A patent/CN111157403B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4196614A (en) * | 1978-01-20 | 1980-04-08 | Mclaughlin Robert R | Process and device for quantitative analysis of cement and water content in fresh concrete |
| CN102466607A (en) * | 2010-11-15 | 2012-05-23 | 李波 | Method for measuring intrinsic viscosity number of cationic flocculant |
| CN102353616A (en) * | 2011-06-23 | 2012-02-15 | 中国石油天然气股份有限公司 | Intrinsic viscosity number measuring method for polyacrylamide polymers for oil displacement |
| EP2840395A1 (en) * | 2013-08-22 | 2015-02-25 | Savannah River Nuclear Solutions, LLC | Method for characterization of the rate of movement of an oxidation front in cementitious materials |
| CN103884626A (en) * | 2014-02-21 | 2014-06-25 | 大连大学 | Method for carrying out quantitative classification and qualitative analysis on flocculating constituent |
| CN106977160A (en) * | 2017-05-08 | 2017-07-25 | 天津市滨涛混凝土有限公司 | A kind of non-dispersible underwater concrete and preparation method thereof |
| CN110261265A (en) * | 2019-06-25 | 2019-09-20 | 成都建工赛利混凝土有限公司 | Flocculant detection method and its detection device in a kind of sand |
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