CN110715872A

CN110715872A - Method and device for measuring water-cement ratio of fresh concrete

Info

Publication number: CN110715872A
Application number: CN201911102449.8A
Authority: CN
Inventors: 朴志海; 姚瑞珊; 陈彦君; 孙明刚; 计伟帅; 池波
Original assignee: Heilongjiang Shengshi Xinyu Hi Tech Development Co Ltd; Longjian Road and Bridge Co Ltd
Current assignee: Heilongjiang Shengshi Xinyu Hi Tech Development Co Ltd; Longjian Road and Bridge Co Ltd
Priority date: 2019-11-12
Filing date: 2019-11-12
Publication date: 2020-01-21

Abstract

A method and a device for measuring the water-cement ratio of fresh concrete belong to the technical field of concrete performance test. The calibration cylinder is matched with the circular table type separation sleeve screen and the cylinder type separation sleeve screen for use, and the circular table type separation sleeve screen or the cylinder type separation sleeve screen is matched with the vibration screening device for use; wiping all the instruments, equally dividing four parts of concrete and placing the four parts of concrete into calibration cylinders, pouring the concrete in the two calibration cylinders into a cylinder type separation sleeve screen, placing the sleeve screen into a vibration screening device and fixing, starting a vibration motor, separating the concrete until mortar is completely screened, unloading the sleeve screen, pouring the mortar into the calibration cylinders, and repeating the steps for the other two calibration cylinders; uniformly stirring the obtained mortar, equally dividing the obtained mortar into six parts, dividing the six parts into two groups, performing a drying test on one group of mortar, and calculating the average mass of water; and (3) performing a washing test on the other group of mortar, calculating the average mass of the cement and other mineral admixtures, and finally calculating the water-to-gel ratio. The invention ensures the use quality of the concrete and improves the safety of the concrete.

Description

Method and device for measuring water-cement ratio of fresh concrete

Technical Field

The invention relates to a method and a device for measuring the water-cement ratio of fresh concrete, belonging to the technical field of concrete performance test.

Background

The concrete is artificial stone which is prepared by taking cement as a main cementing material, adding water, sand, stones and chemical additives and mineral admixtures if necessary, mixing the materials according to a proper proportion, uniformly stirring, densely forming, curing and hardening. Concrete is mainly divided into two stages and states: plastic state before setting and hardening, namely fresh concrete or concrete mixture; hardened, i.e. hardened concrete or concrete. The concrete water-cement ratio refers to the ratio of water consumption per cubic meter of concrete to the consumption of all cementing materials.

The water-cement ratio of concrete is an extremely important factor influencing the strength and quality of concrete. In many links of concrete stirring, transportation, pouring and the like, the actual water-cement ratio is often greatly fluctuated compared with the designed water-cement ratio due to natural or artificial reasons, and the actual water-cement ratio is larger than the designed water-cement ratio in most cases, so that the design strength and quality of the concrete are difficult to ensure; in addition, it is difficult to accurately control the water-cement ratio during the concrete mixing process for various reasons during the construction.

Disclosure of Invention

In order to solve the problems in the background art, the invention provides a method and a device for measuring the water-cement ratio of fresh concrete.

The invention adopts the following technical scheme: a measuring device for the water-cement ratio of fresh concrete comprises a vibrating screen, a cylindrical separating sleeve screen, a circular truncated cone type separating sleeve screen and a plurality of calibration cylinders, wherein the calibration cylinders are matched with the circular truncated cone type separating sleeve screen and the cylindrical separating sleeve screen for use, and the circular truncated cone type separating sleeve screen or the cylindrical separating sleeve screen is matched with the vibrating screen for use; the vibrating screen comprises a base, a placing seat, a vibrating motor, a water outlet pipe, a pressing plate, a top beam, a locking screw rod, a plurality of damping springs and a plurality of auxiliary sliding rods; the base is connected with the placing seat through the damping springs of a plurality of vertical settings, the bottom of placing the seat is fixed with vibrating motor and sets up with the outlet pipe intercommunication to supplementary slide bar and back timber fixed connection through a plurality of vertical settings, the limit portion sliding connection and the accessible locking screw of a plurality of supplementary slide bars and clamp plate carry out spacing fixed to the two.

The invention discloses a method for measuring a water-cement ratio of fresh concrete, which comprises the following steps:

the method comprises the following steps: wiping and wetting the vibration screening device, the cylinder type separation sleeve screen, the circular truncated cone type separation sleeve screen and the plurality of calibration cylinders by using clean wet cloth;

step two: taking 15L-20L of fresh concrete to be measured, uniformly stirring and dividing into four parts;

step three: respectively placing the four fresh concrete in the step two into the corresponding cylinders of the four calibration cylinders, and sealing the cylinders through corresponding sealing covers, wherein the operation time is shorter than 120 s;

step four: pouring the fresh concrete in two of the calibration cylinders in the third step into an upper screen of the cylinder type separation sleeve screen, and sealing by using a screen cover;

step five: placing the cylindrical separation sleeve screen in the fourth step into a vibration screening device and fixing;

step six: starting a vibration motor, and starting to vibrate and separate the fresh concrete in the cylindrical separation sleeve screen until the mortar in the concrete is screened;

step seven: unloading the cylindrical separation sleeve screen in the sixth step, pouring the mortar in the first screen bottom prepared in the sixth step into a cylinder body of a new calibration cylinder, and sealing through a corresponding sealing cover;

step eight: taking fresh concrete of the other two calibration cylinders in the third step, and repeating the fourth step to the seventh step;

step nine: quickly and uniformly mixing the mortar prepared in the seventh step and the mortar prepared in the eighth step, uniformly dividing the mixture into six parts, and respectively filling the six parts into corresponding containers for sealing;

step ten: dividing the six parts of mortar in the ninth step into two groups randomly;

step eleven: performing a drying test on the group of the mortar in the step ten, and calculating the average mass of water in three parts of the mortar in the group;

step twelve: performing a washing test on the other group of mortar in the step ten, and calculating the average mass of cement and other mineral admixtures in three mortar samples in the group;

step thirteen: and calculating the water-cement ratio of the concrete according to a water-cement ratio formula.

Compared with the prior art, the invention has the beneficial effects that:

the method solves the technical problem of actually measuring the water-cement ratio of the fresh concrete in the concrete construction, has strong operability, is convenient, real-time, quick and accurate, can quickly detect the water-cement ratio of the concrete in the construction, quickly judges whether the water-cement ratio meets the design requirements or not, ensures the use quality of the concrete and improves the safety of the concrete.

Drawings

FIG. 1 is an isometric view of the overall construction of a calibration cylinder;

FIG. 2 is an isometric view of the overall construction of the vibratory screen;

FIG. 3 is a schematic view of the internal structure of the pressure plate when it is freely movable;

FIG. 4 is a schematic view of the internal structure of FIG. 3 when locked;

FIG. 5 is an isometric view of the overall construction of a cartridge separation jacket screen, with the screen cover not drawn for clarity;

figure 6 is an isometric view of the overall construction of a frusto-conical separating jacket screen.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the invention, rather than all embodiments, and all other embodiments obtained by those skilled in the art without any creative work based on the embodiments of the present invention belong to the protection scope of the present invention.

The first embodiment is as follows: as shown in fig. 1 to 6, the invention discloses a device for measuring the water-cement ratio of fresh concrete, which comprises a vibrating screen, a cylindrical separating sleeve screen, a circular truncated cone type separating sleeve screen and a plurality of calibration cylinders, wherein the calibration cylinders are matched with the circular truncated cone type separating sleeve screen and the cylindrical separating sleeve screen for use, and the circular truncated cone type separating sleeve screen or the cylindrical separating sleeve screen is matched with the vibrating screen for use; the vibrating screen comprises a base 21, a placing seat 23, a vibrating motor 24, a water outlet pipe 25, a pressing plate 27, a top beam 28, a locking screw 29, a plurality of damping springs 22 and a plurality of auxiliary sliding rods 26; the upper end of base 21 is connected with the lower extreme of placing seat 23 through a plurality of damping spring 22 of vertical setting, the bottom of placing seat 23 is fixed with vibrating motor 24 and sets up with outlet pipe 25 intercommunication to through a plurality of vertical setting's supplementary slide bar 26 and back timber 28 fixed connection, the limit portion sliding connection of a plurality of supplementary slide bars 26 and clamp plate 27 and accessible locking screw 29 carry out spacing fixed to the two.

The second embodiment is as follows: as shown in fig. 1, the present embodiment is further described with respect to the first embodiment, each of the calibration cylinders includes a cylinder body 11 and a sealing cover 12, each of the cylinder bodies 11 is in a shape of an inverted circular truncated cone, and each of the cylinder bodies 11 seals concrete through the corresponding sealing cover 12; when the mortar is used, concrete in the corresponding calibration cylinder is poured into the cylinder type separation sleeve screen, or mortar separated by the cylinder type separation sleeve screen is poured into the corresponding calibration cylinder.

The third concrete implementation mode: as shown in fig. 2, in the present embodiment, a plurality of inner legs 210 are disposed in the placing seat 23, and the inner legs 210 are uniformly distributed along the circumferential direction of the placing seat 23.

The fourth concrete implementation mode: as shown in fig. 3 and 4, this embodiment is a further description of the third embodiment, the edge of the pressing plate 27 is slidably sleeved on the plurality of auxiliary sliding rods 26, a plurality of sliding grooves 271 are arranged in the pressing plate 27 along the radial direction, a locking sliding rod 272 is slidably arranged in each sliding groove 271, a contact block moving groove 273 is arranged in the middle of the pressing plate 27, the collision block movable groove 273 is communicated with the sliding grooves 271, the middle part of the groove top surface of the collision block movable groove 273 penetrates through the upper surface of the pressing plate 27 and is provided with a threaded hole, the threaded hole is in threaded connection with a vertically arranged locking screw 29, the lower end of the locking screw 29 is fixed with a collision block 291, the contact block 291 is an isosceles trapezoid structure and is located in the contact block moving groove 273, and each locking slide bar 272 and the adjacent end of the contact block 291 are provided with wedge-shaped surfaces matched with the isosceles trapezoid.

The fifth concrete implementation mode: as shown in fig. 5, this embodiment is further described with respect to the third embodiment, the cylindrical separation sleeve includes a cover, an upper screen 31, a lower screen 32 and a first screen bottom 33, the cover, the upper screen 31, the lower screen 32 and the first screen bottom 33 have the same diameter and are sleeved and connected from top to bottom, the upper screen 31 and the lower screen 32 are both square-hole screens, and the side length of the mesh of the upper screen 31 is greater than that of the mesh of the lower screen 32; when the cylindrical separating sleeve sieve is used, the cylindrical separating sleeve sieve is placed on the inner support legs 210 in the vibrating sieving device and is pressed and fixed through the pressing plate 27, the side length of the mesh opening of the upper sieve 31 is 9.5mm, and the side length of the mesh opening of the lower sieve 32 is 4.75 mm.

The sixth specific implementation mode: as shown in fig. 6, in this embodiment, a third embodiment is further described, the circular truncated cone type separating sleeve sieve includes a circular truncated cone sieve 41 and a second sieve bottom 42, a sieve bottom surface of the circular truncated cone sieve 41 and the second sieve bottom 42 have the same diameter, and the circular truncated cone sieve 41 and the second sieve bottom 42 are connected in a sleeved manner from top to bottom; the second sieve bottom 42 is provided with a water outlet; when the circular truncated cone type separating sleeve sieve is used, the circular truncated cone type separating sleeve sieve is placed on the inner support legs 210 in the vibrating sieving device and is compressed and fixed through the pressing plate 27, and the circular truncated cone type separating sleeve sieve 41 is a square-hole sieve with meshes with side length of 0.075 mm.

The seventh embodiment: an assay method according to any one of the first to sixth embodiments, comprising the steps of:

preparation work

1. The concrete construction mixing ratio for mixing the concrete is prepared.

2. And (3) detecting the mud content and the mud block content of the fine aggregate (sand). If the field inspection of the concrete raw material is finished, the test can be omitted, and the finished detection data can be directly taken to be applied to the calculation of the water-cement ratio. The test adopts a sand-stone set screen (the test method adopts the current national standard GB/T14684-2011 construction sand, the 7 th item 4 on the 7 th page and the 7 th item 6 on the 9 th page).

3. Detecting the content of screen residue which is larger than 0.075mm in cement and other mineral admixtures. In order to cooperate with the work of flushing mortar in the detection process, a water sieve method is adopted for detecting the content of the residue on sieve which is larger than 0.075mm in cement and other mineral admixtures (the test method can refer to the current national standard GB/T1345-2005 sieve analysis method for cement fineness test method, item 5-8 on page 1-5), and the sieve for detecting the content of the residue on sieve which is larger than 0.075mm in cement and the content of fine aggregate mud adopt 0.075mm square-hole sieves, which is the same as the step 2. And the content of the screen residue which is larger than 0.075mm in the cement is detected by adopting vibration and combining a water screening method. This is the original creation of the present invention.

4. It should be noted that the above-mentioned detection method is only applicable to the present invention, and must not be used as a basis for determining whether the fineness of cement and other mineral admixtures is qualified or not, because the above-mentioned detection method is specified according to the current national standard: the screen hole diameter of the screen for detecting the fineness of the cement and other mineral admixtures is 0.08mm square hole screen instead of 0.075mm square hole screen.

5. The present invention does so because: in the process of measuring the water-cement ratio, when the mortar is washed by vibration and a water sieving method, cement particles smaller than 0.075mm in cement and soil smaller than 0.075mm in fine aggregate are washed to the position below a sieve together. The invention is convenient for detection operation and subsequent calculation work.

6. The amount of oversize material greater than 0.075mm in cement and other mineral admixtures was measured not for the actual fineness of the cement but for the calculation of the amount of oversize material greater than 0.075mm in the cement. This fraction of particles is contained in the particulate screen residue greater than 0.075mm after washing and drying of the mortar, mixed with the fine aggregate.

7. After the 2 nd work and the 6 th work are finished, the mass of mud and mud blocks smaller than 0.075mm in the fine aggregate and the mass of screen residue larger than 0.075mm in the cement can be calculated by combining the theoretical mixing proportion of the concrete, and a foundation is laid for measuring and calculating the mass of the cement in the mortar.

8. After the work is finished, the quality of the cement in the mortar can be calculated.

(II) Main instrument

1. A plurality of concrete calibration cylinders are provided;

2. a cylinder type separating sleeve screen (comprising a screen cover, an upper screen 31 (a 4.75mm square hole screen), a lower screen 32 (a 9.5mm square hole screen) and a screen bottom 33;

3. the circular truncated cone type separating sleeve screen comprises a circular truncated cone screen 41 (a 0.075mm square hole screen) and a second screen bottom 42;

4. a vibratory screen;

5. an electronic balance: weighing one table at maximum by 10kg, and sensing quantity by 0.01 g; weighing one table at maximum of 5kg, and sensing quantity of 0.01 g; one piece of the powder was weighed at maximum 1kg, and the sensory quantity was 0.01 g.

6. One blast drying box and three electric furnaces are arranged;

7. auxiliary equipment: tap, iron plate, spade, small shovel, brush, rag, air conditioner and humidifier

(III) laboratory Environment

1. Temperature: 20 +/-5 DEG C

2. Humidity: 70% RH is less than or equal to 85% RH

(IV) method for measuring water-cement ratio of fresh concrete

The method comprises the following steps: wiping and wetting the vibration screening device, the cylinder type separation sleeve screen, the circular truncated cone type separation sleeve screen and the plurality of calibration cylinders by using clean wet cloth so as to ensure that the fresh concrete is not absorbed when contacting with the fresh concrete;

step three: respectively placing the four fresh concrete in the step two into the cylinder bodies 11 of the corresponding four calibration cylinders, and sealing the four fresh concrete through the corresponding sealing covers 12, wherein the operation time is shorter than 120 s;

taking 15L-20L of representative fresh concrete with the water-gel ratio to be measured, pouring the concrete on a wet iron plate in advance, stirring the concrete quickly and fully, and piling the concrete into a cake shape with the middle gradually higher. Then, the concrete is divided into four parts by a quartering method, four concrete calibration cylinders are evenly filled in the four parts of the concrete at opposite corners, the concrete in the four concrete calibration cylinders is weighed by a balance to ensure the same quality, and the concrete is sealed by a sealing cover 12. The whole operation process is guaranteed to be completed within 120 s.

Step four: pouring the fresh concrete in two of the calibration cylinders in the third step into an upper screen 31 of the cylinder type separation sleeve screen, and sealing by using a screen cover;

the cylindrical separation nested screen is placed on a plurality of inner supporting legs 210 of the vibrating screen separator, the pressing plate 27 is pushed to be completely pressed on the screen cover, the locking screw 29 is rotated to move upwards, then the contact block 291 is driven to move upwards, then the locking sliding rods 272 are pushed to extrude the corresponding auxiliary sliding rods 26, and then the position of the pressing plate 27 is fixed, namely the cylindrical separation nested screen is fixed.

Step six: starting a vibration motor 24, and starting to vibrate and separate the fresh concrete in the cylindrical separation sleeve screen until the mortar in the concrete is screened;

step seven: unloading the cylindrical separation nested screen in the sixth step, pouring the mortar in the first screen bottom prepared in the sixth step into a cylinder body 11 of a new calibration cylinder, and sealing through a corresponding sealing cover 12;

pouring the concrete in two of the concrete calibration cylinders into a cylinder type separation sleeve screen, wherein the sleeve screen consists of a 9.5mm square hole screen, a 4.75mm square hole screen and a screen bottom, covering a screen cover, and simultaneously placing the sleeve screen on a vibration screening device and fixing the sleeve screen. And starting the vibrating screen, and starting to vibrate the concrete in the separating cylinder type separating sleeve screen until the mortar in the concrete is basically screened out. And (4) unloading the set of screen, pouring all mortar in the first screen bottom into the spare concrete calibration cylinder, and simultaneously covering the sealing cover 12 of the concrete calibration cylinder. The operation is then repeated with the remaining two concrete calibration cylinders.

combining the mortar sieved by 4.75mm after twice sieving into a concrete calibration cylinder for rapid and uniform mixing, uniformly weighing 6 parts of the uniformly stirred mortar, wherein each part is 500g in mass, and subpackaging the uniformly weighed mortar into 6 enamel plates with proper size. And dividing the weighed 6 parts of samples into two groups randomly, and keeping three parts of mortar in each group for later use.

The mass of the components (composition components) of the two groups of three parts of mortar, namely six parts of mortar, is assumed to be completely the same, so that the data of the same components and the same mass are shared in a washing test and a drying test by using an equivalent substitution method, and finally, the water-cement ratio of the concrete is accurately calculated. The method for calculating the water-cement ratio of fresh concrete is that the ratio of concrete mixing water to cement and other mineral admixtures.

And (3) respectively carrying out drying and washing tests on the two groups of mortar. After the drying test is finished, the average mass of water in the three mortar samples can be calculated, after the washing test is finished, the average mass of cement and other mineral admixtures in the three mortar samples can be calculated, and the water-cement ratio of the concrete can be calculated according to a water-cement ratio formula. The specific test procedures and methods are described below.

The specific implementation mode is eight: the assay method according to embodiment seven, the step eleven comprising the steps of:

the method comprises the following steps: randomly selecting the group of mortar, respectively weighing the three mortar masses, simultaneously placing the mortar masses into a blast drying box which is heated to 105 +/-5 ℃ in advance, and drying the mortar masses to constant weight; the constant weight means that the difference between two adjacent times of weighing is less than the weighing precision required by the test when the time interval between two adjacent times of weighing is more than 3h, and the following is the same.

Step two: taking out the mortar in the first step, putting the mortar into a dryer, cooling the mortar to room temperature, and weighing the mortar; to the nearest 0.01g of the total amount of the particles,

step three: calculating the average mass of the three parts of the mortar in the group after drying,

for the dried three-part mortar, the mass of the three-part mortar before drying is m₁、m₂、m₃Wherein the mass of three dried mortar is m'₁、m′₂、m′₃The average mass of the three parts of mortar after drying is

It is calculated as

Setting the mass of water in the three parts of mortar as w1, w2 and w3 respectively, then w₁＝m₁-m′₁、w₂＝m₂-m′₂、w₃＝m₃-m′₃. The average mass of water in the three parts of mortar is set as

Then

In the above formulas, the mass units of the mortar and the water are all g, and the calculation is accurate to 0.01 g. The arithmetic mean of the masses of water in the three mortar samples was used as the measured value.

The specific implementation method nine: the assay method according to embodiment seven, the step twelve comprising the steps of:

the method comprises the following steps: randomly selecting one mortar from the other group of mortars and pouring the mortar into a circular table sieve 41 of the circular table type separation sleeve sieve;

step two: putting the circular truncated cone type separating sleeve screen in the first step into a vibrating screen separator and fixing;

step three: fixing a circular truncated cone type separating sleeve screen, fully washing mortar in a circular truncated cone type screen 41 by using water flow flowing out of a faucet which is right opposite to the sleeve screen, simultaneously starting a vibration motor 24, and washing the mortar in the sleeve screen by using water flow while vibrating and screening until fine aggregates, cement and other mineral admixtures in the mortar are completely washed, and the water flowing out of a water outlet at the bottom of the sleeve screen is completely changed into clear water flow, wherein the working time is about 200-300 s;

step four: turning off the power supply and the water flow, and putting the residual substances on the circular truncated cone type separating sleeve sieve into a corresponding container;

step five: repeating the second step to the fourth step on the other two portions of mortar;

step six: carefully transferring the residual substances on the three mortar sieves in the fourth step and the fifth step into proper enamel trays respectively (taking care not to cause any loss of the residues on the sieves), and simultaneously putting the residual substances in the three containers into a blast drying box which is heated to 105 +/-5 ℃ in advance, and drying to constant weight;

step seven: taking out the mortar in the sixth step, putting the mortar into a dryer, cooling the mortar to room temperature, and weighing the mortar; to the nearest 0.01g

Step eight: calculating the average mass of the three dried residual substances in the group,

the average mass of the dried substances after washing the residual substances in the three parts of mortar is set as

Corresponding washed-off mud and mud lumps have an average mass of

The average mass of the dry state of cement and other mineral admixtures in the three washed mortar samples before washing is set as

It is washed with water and separated into two parts, one part is the part under the sieve of less than 0.075mm, and the other part is used

Indicating that the part has been washed away by water during the water wash and that its mass is not considered when weighing; the other part is larger than 0.075mmIndicating that the fraction is a reject.

Calculating the average mass of cement and other mineral admixtures:

in the formula:

the average mass of cement and other mineral admixtures in the three washed mortar samples is accurate to 0.01g in unit g.

The average mass of the three dried mortar samples in unit g is accurate to 0.01g, and the value can be directly calculated by the third step in the eighth embodiment.

The average mass of the sieve residue of the three washed mortar samples is dried, the unit g is accurate to 0.01g, and the value can be directly obtained by the eighth step in the ninth embodiment.

The average mass of the mud and the mud blocks smaller than 0.075mm in the three parts of mortar fine aggregate is accurate to 0.01g in unit g. This data can be obtained from step 2 in the preparation work.

The average mass of the residue of the sieve with the sieve holes larger than 0.075mm, unit g, of the cement and other mineral admixtures in the three parts of mortar is accurate to 0.01 g. This data can be obtained from step 3 in the preparation work (a).

Calculating the water-cement ratio of concrete

The water-to-cement ratio of concrete is defined as the mass of water divided by the mass of cement and other mineral admixtures. Namely:

in the formula:

the average mass of water in the three mortar samples for drying, in g, is accurate to 0.01g, and the value can be directly calculated by the specific embodiment eight.

The average mass of cement and other mineral admixtures in the three washed mortar samples, unit g, is accurate to 0.01g, and the value is obtained by calculating according to the ninth embodiment.

(V) description of the invention

1. When a blast drying oven is used for drying mortar or drying the oversize materials on the sieve in the steps, an electric furnace can be used for drying to improve the working efficiency, the materials are dried by the method, and all tests can be completed within 100-120 min; the former drying method is adopted, and the completion of all tests needs about 210min to 240 min. The material is dried by an electric furnace drying method, and the work efficiency can be improved by about 2 times. The method for drying materials by using a blast drying box is a standard method, and the method for drying materials by using an electric furnace is a substitute method. The user can select and choose by himself.

2. The invention is tested by engineering practice for many years and is proved by combining a large number of tests: the absolute error between the actual measured water-cement ratio and the theoretical water-cement ratio of the fresh concrete is +/-0.002-0.008. Has high practical value.

Second, other explanations

Concrete calibration cylinder

1. Basic information of concrete calibration cylinder:

the material is Q235C carbon structural steel with the surface roughness of R_a3.2, with a volume of about 2.2L.

2. The concrete calibration cylinder has the following functions:

(1) the method is used for calibrating the quality of concrete so as to ensure that the quality of the concrete for separating mortar is the same.

(2) Is used for uniformly distributing the components of the concrete so as to ensure that the contents and the qualities of the components of the mortar for separating the fine aggregate, the cement and the mineral admixture are basically the same.

(3) The device is used for temporarily storing concrete and keeping the mixing water in the concrete nonvolatile, and is used for ensuring that the mixing water contained in the fresh concrete is not lost before the drying test, so as to ensure the accuracy of the test of the invention.

(4) And temporarily storing the mortar, and keeping the mixing water in the mortar not volatile so as to ensure that the mixing water contained in the mortar is not lost before the drying test, thereby ensuring the accuracy of the test of the invention.

(5) Used as a mortar mixer for uniformly mixing mortar.

3. The use method of the concrete calibration cylinder comprises the following steps:

(1) taking 15L-20L of representative fresh concrete with the water-gel ratio to be measured, pouring the concrete on a wet iron plate in advance, stirring the concrete quickly and fully, and piling the concrete into a cake shape with the middle gradually higher. Then dividing the concrete into four parts by a quartering method, evenly filling four concrete calibration cylinders into the four diagonal corners of the concrete, weighing the concrete in the four concrete calibration cylinders by a balance to ensure the same quality, and sealing and covering the upper openings of the four concrete calibration cylinders for later use. The whole operation process is guaranteed to be completed within 120 s.

(2) The concrete in two of the concrete calibration cylinders is poured into a cylinder type separation sleeve screen, a screen cover is covered, and the sleeve screen is placed on a vibration screening device and fixed. And starting the vibrating screen to vibrate the concrete in the separating sleeve screen until the mortar in the concrete is basically screened out. The set of screen is disassembled, the mortar in the screen bottom is poured into the spare concrete calibration cylinder, and the sealing cover 12 of the concrete calibration cylinder is covered at the same time. The operation is then repeated with the remaining two concrete calibration cylinders.

(3) Combining the mortar sieved by 4.75mm after twice sieving into a concrete calibration cylinder for rapid and uniform mixing, uniformly weighing 6 parts of the uniformly stirred mortar, wherein each part is 500g in mass, and subpackaging the 6 parts of the mortar into 6 enamel trays with proper size. And dividing the weighed 6 parts of samples into two groups randomly, and keeping three parts of mortar in each group for later use.

(II) cylinder type separating screen set

1. Basic information of the cylindrical separation screen:

the material is Q235C carbon structural steel, and the roughness of the inner surface is R_a3.2。

2. The function of the cylinder type separation sleeve screen is as follows:

(1) used for separating coarse aggregate and mortar in concrete.

(2) Because the concrete has more coarse aggregate content and larger mass, two screens, namely a 9.5mm square-hole screen and a 4.75mm square-hole screen, are selected during screening, so that the operation is quicker and more convenient.

3. The application method of the cylinder type separation sleeve screen comprises the following steps:

(III) round platform type separating sleeve screen

1. Basic information of the circular truncated cone type separating sleeve screen:

the material is Q235C carbon structural steel with the surface roughness of R_a3.2。

2. The function of the circular table type separating sleeve screen is as follows:

used for separating fine aggregate and cement and other mineral admixtures in the mortar.

3. The use method of the circular truncated cone type separating sleeve screen comprises the following steps:

(1) taking out any one of the other three mortar samples for later use, and pouring into the circular truncated cone type separating sleeve sieve. Fixing the set screen, opening a water tap opposite to the set screen, fully flushing the mortar in the set screen by tap water, simultaneously starting a power supply of the vibration screening device, flushing the mortar in the set screen by the tap water while vibrating and screening for about 200-300 s until all gelled materials such as fine aggregate cement and other mineral admixtures in the mortar are flushed, and completely changing water flowing out from a water outlet of the second 42 bottom of the set screen into clear water flow. The power supply and the faucet can be turned off at this time. And then, respectively and sequentially finishing the washing test of the two residual mortar to be washed by water according to the steps.

(2) Three parts of fine aggregate such as the sieved fine aggregate on the washed mortar are carefully transferred into a proper enamel tray respectively (the sieved residue on the sieve is not lost), and then the three parts are put into a blast drying box which is heated to 105 +/-5 ℃ in advance at the same time, dried to constant weight, carefully taken out and put into a dryer, and weighed respectively after being cooled to be accurate to 0.01 g.

(IV) vibrating screen

1. Basic information of vibratory screen:

the placing seat 23, the pressing plate 27, the top beam 28 and the auxiliary sliding rods 26 are all made of Q235C carbon structural steel;

the base 21 is made of 12^#And 8^#Channel steel;

a plurality of shock absorbing springs 22 of 70^#Steel wire spring steel;

the power of the vibration motor 24 is 0.5kw, the rotating speed is 1460r/min, and the voltage is 380 v.

2. The function of the vibrating screen:

used for assisting in separating coarse aggregate and mortar in concrete; to assist in the separation of fine aggregate and cement and other mineral admixtures in the mortar.

3. The use method of the vibrating screen comprises the following steps:

(3) Taking out any one of the other three mortar samples for later use, pouring the mortar sample into a circular truncated cone type separating sleeve screen, fixing the sleeve screen, opening a water tap opposite to the sleeve screen, fully washing the mortar in the sleeve screen by tap water, simultaneously starting a power supply of a vibrating screen device, washing the mortar in the sleeve screen by tap water while vibrating and screening for about 200-300 s until all gelled materials such as fine aggregate cement and other mineral admixtures in the mortar are completely washed, and completely changing water flowing out from a water outlet of the second 42 sieve bottom into clear water flow. The power supply and the faucet can be turned off at this time. And then, respectively and sequentially finishing the washing test of the two residual mortar to be washed by water according to the steps.

It is obvious to a person skilled in the art that the invention is not restricted to details of the above-described exemplary embodiments, but that it can be implemented in other carrier forms without departing from the spirit or essential characteristics of the invention. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. The utility model provides a survey device of fresh concrete water-cement ratio which characterized in that: the circular platform type separation sleeve screen or the cylindrical separation sleeve screen is matched with the vibration screening device; the vibrating screen comprises a base (21), a placing seat (23), a vibrating motor (24), a water outlet pipe (25), a pressing plate (27), a top beam (28), a locking screw (29), a plurality of damping springs (22) and a plurality of auxiliary sliding rods (26); the base (21) is connected with a placing seat (23) through a plurality of vertically arranged damping springs (22), the bottom of the placing seat (23) is fixed with a vibration motor (24) and is communicated with a water outlet pipe (25) and is fixedly connected with a top beam (28) through a plurality of vertically arranged auxiliary sliding rods (26), and the auxiliary sliding rods (26) are in sliding connection with the edges of a pressing plate (27) and can be limited and fixed through locking screw rods (29).

2. The apparatus for measuring the water-cement ratio of fresh concrete according to claim 1, wherein: each calibration cylinder comprises a cylinder body (11) and a sealing cover (12), and each cylinder body (11) is in an inverted circular truncated cone shape and is sealed through the corresponding sealing cover (12); when the mortar is used, concrete in the corresponding calibration cylinder is poured into the cylinder type separation sleeve screen, or mortar separated by the cylinder type separation sleeve screen is poured into the corresponding calibration cylinder.

3. The apparatus for measuring the water-cement ratio of fresh concrete according to claim 1, wherein: a plurality of inner support legs (210) are arranged in the placing seat (23), and the inner support legs (210) are uniformly distributed along the circumferential direction of the placing seat (23).

4. The apparatus for measuring the water-cement ratio of fresh concrete according to claim 3, wherein: the edge of the pressing plate (27) is slidably sleeved on the auxiliary sliding rods (26), a plurality of sliding grooves (271) are arranged in the pressing plate (27) along the radial direction of the pressing plate, a locking sliding rod (272) is slidably arranged in each sliding groove (271), a contact block moving groove (273) is arranged in the middle of the pressing plate (27), the contact block moving groove (273) is communicated with the sliding grooves (271), the middle part of the groove top surface of the contact block moving groove (273) penetrates through the upper surface of the pressing plate (27) and is provided with a threaded hole, the threaded hole is in threaded connection with a locking screw rod (29) which is vertically arranged, a contact block (291) is fixed at the lower end of the locking screw rod (29), the contact block (291) is of an isosceles trapezoid structure and is located in the movable groove (273) of the contact block, and each locking sliding rod (272) and one end, adjacent to the contact block (291), of each locking sliding rod are provided with wedge-shaped surfaces matched with the isosceles trapezoids.

5. The apparatus for measuring the water-cement ratio of fresh concrete according to claim 3, wherein: the cylindrical separating nested screen comprises a screen cover, an upper screen (31), a lower screen (32) and a screen bottom I (33), wherein the screen cover, the upper screen (31), the lower screen (32) and the screen bottom I (33) have the same diameter and are connected in a nested manner from top to bottom, the upper screen (31) and the lower screen (32) are both square-hole screens, and the side length of meshes of the upper screen (31) is greater than that of meshes of the lower screen (32); in use, the cylindrical separating screen is placed on a plurality of inner support legs (210) in the vibrating screen and is pressed and fixed by a pressing plate (27).

6. The apparatus for measuring the water-cement ratio of fresh concrete according to claim 3, wherein: the circular truncated cone type separating sleeve sieve comprises a circular truncated cone sieve (41) and a sieve bottom II (42), the sieve bottom surface of the circular truncated cone sieve (41) has the same diameter as the sieve bottom II (42), and the circular truncated cone sieve (41) and the sieve bottom II (42) are connected in a sleeved mode from top to bottom; the second sieve bottom (42) is provided with a water outlet; when the circular truncated cone type separating sleeve screen is used, the circular truncated cone type separating sleeve screen is placed on a plurality of inner supporting legs (210) in the vibrating screening device and is compressed and fixed through the pressing plate (27).

7. An assay method using the assay device according to any one of claims 1 to 6, characterized in that: the method comprises the following steps:

step three: respectively placing the four fresh concrete in the step two into the corresponding cylinder bodies (11) of the four calibration cylinders, and sealing the four fresh concrete through corresponding sealing covers (12), wherein the operation time is shorter than 120 s;

step four: pouring the fresh concrete in two of the calibration cylinders in the third step into an upper screen (31) of the cylinder type separation sleeve screen, and sealing by using a screen cover;

step six: starting a vibration motor (24) to vibrate and separate the fresh concrete in the cylindrical separation sleeve screen until the mortar in the concrete is screened;

step seven: unloading the cylindrical separation nested screen in the sixth step, pouring the mortar in the first screen bottom prepared in the sixth step into a cylinder body (11) of a new calibration cylinder, and sealing through a corresponding sealing cover (12);

8. The method for measuring according to claim 7, wherein: the eleventh step comprises the following steps:

the method comprises the following steps: randomly selecting the group of mortar, respectively weighing the three mortar masses, simultaneously placing the mortar masses into a blast drying box which is heated to 105 +/-5 ℃ in advance, and drying the mortar masses to constant weight;

step two: taking out the mortar in the first step, putting the mortar into a dryer, cooling the mortar to room temperature, and weighing the mortar;

9. the method for measuring according to claim 8, wherein: the twelfth step includes the steps of:

the method comprises the following steps: one part of mortar is selected from the other group of mortar and poured into a circular table sieve (41) of the circular table type separation sleeve sieve;

step three: washing the mortar in the circular truncated cone sieve (41) by water flow, and simultaneously starting the vibration motor (24) until the water flowing out of the water outlet pipe (25) is completely changed into clear water flow;

step six: putting the residual substances in the three containers into a blast drying box which is heated to 105 +/-5 ℃ in advance, and drying to constant weight;

step seven: taking out the mortar in the sixth step, putting the mortar into a dryer, cooling the mortar to room temperature, and weighing the mortar;

step eight:calculating the average mass of the three dried residual substances in the group,