Cement mortar early-stage shrinkage testing device capable of regulating and controlling evaporation area

Abstract

The utility model relates to a cement mortar early-stage shrinkage testing device capable of regulating and controlling an evaporation area. The method is suitable for concrete testing. According to the technical scheme, the cement mortar early-stage shrinkage testing device capable of regulating and controlling the evaporation area comprises a shrinkage mold, and the shrinkage mold is provided with a supporting base, a base plate and a clamping device, the cylindrical mold is annularly divided into a steel bottom film and a steel outer film, the steel bottom film is arranged on the supporting base, and the steel outer film is provided with an evaporation window; the steel side die can be combined and connected with the supporting base and can seal two end openings of the cylindrical die when being connected with the base; the flexible plastic partition plate is arranged to be cylindrical and tightly attached to the interior of the cylindrical mold, the flexible plastic partition plate is annularly divided into a plastic bottom partition plate body and a plastic outer partition plate body, and the position of the plastic outer partition plate body corresponds to the evaporation window in the steel outer film; the waterproof film covers the inner wall of a pouring cavity defined by the flexible plastic partition plate and the steel side molds at the two ends.

Description

TECHNICAL FIELD

[0001] The utility model relates to a cement mortar early shrinkage testing device of adjustable evaporation area, which is suitable for the technical field of concrete testing. BACKGROUND

[0002] Cement mortar is a kind of multiphase composite material composed of cement, fine aggregate and water, which is widely used in the field of construction engineering. Due to the deficiency of material preparation technology, the water-binder ratio of cement mortar was usually high in the last century, and the porosity in the hardened paste was large, so the compressive strength of the mortar was low, and the long-term shrinkage problem of high water-binder ratio mortar was more obvious than the early shrinkage. After that, with the advent of high-efficiency water reducing agent, the agglomeration problem of cement particles was effectively solved, most of the free water wrapped by cement particles was released, the water consumption of cement mortar was greatly reduced, and at the same time, the industry development trend of reducing backward production capacity and optimizing product performance was met, low water-binder ratio high-strength and super-high-strength cement mortar was gradually popularized to meet the engineering construction needs of building structure repair and reinforcement, bridge waterproofing and leakage repair, pipeline repair and river regulation. However, low water-binder ratio cement-based materials generally have the problem of large early shrinkage, which is easy to induce the initiation and development of internal micro-cracks when the base resistance is low, which brings significant cracking risk and endangers the long-term durability of the material, so it is of great scientific significance to accurately determine the early shrinkage of high-strength cement mortar under different working conditions.

[0003] The early shrinkage of cement-based materials after setting is closely related to the evaporation of internal free water, and the structure of cement mortar products is diverse, so it is difficult to scientifically define the influence of external environment on the early shrinkage of materials by only using single evaporation amount or evaporation area, therefore, some specifications use the ratio of evaporation area to volume of the test piece as a key parameter index to evaluate the early shrinkage rule of cement-based materials. The current domestic standard mainly focuses on the long-term shrinkage problem of high water-binder ratio cement mortar, and there are few test methods for the early shrinkage of low water-binder ratio mortar, and in order to improve the convenience of testing, the shape of the related shrinkage test piece is usually a prism, but the distance from each part of the side surface of the prism test piece to the center of the test piece is different, which cannot well realize the goal of adjusting the evaporation area of the test piece with a set of molds, and thus it is difficult to accurately determine the material shrinkage under different evaporation area and volume ratios, considering that the parameter ratio has important engineering value, it is necessary to propose a shrinkage testing device with adjustable evaporation area to meet the testing requirements of low water-binder ratio cement mortar early shrinkage under different working conditions as much as possible under the premise of controlling cost and ensuring analysis accuracy.

[0004] The prism body shrinkage test method has a wide application range in the prior art, but the method cannot well measure the mortar shrinkage under different evaporation area and volume ratios, and has functional limitations. In addition, the corrugated pipe shrinkage test method is also common, and the method is mainly used for testing material autogenous shrinkage, and has a high implementation cost, and also cannot meet the above test requirements. The evaporation area and volume ratio parameter is an important index for analyzing the early shrinkage of high-strength cement mortar under different structural forms, but the current test technology rarely considers the influence of the research parameter, and cannot provide a convenient and efficient test way, which is not conducive to mastering the shrinkage and cracking causes of the material at the early age stage from the theoretical level, and is difficult to provide complete technical guidance for the engineering practice of high-strength and super-high-strength mortar. Practical new content

[0005] The technical problem to be solved by the present application is to provide a cement mortar early shrinkage test device capable of adjusting and controlling evaporation area in view of the above problems.

[0006] The technical scheme adopted by the present application is: a cement mortar early shrinkage test device capable of adjusting and controlling evaporation area, characterized in that it comprises a shrinkage mold, which has:

[0007] a support base;

[0008] a cylindrical mold, which is circumferentially divided into a steel bottom film and a steel outer film, wherein the steel bottom film is arranged on the support base, and the steel outer film is provided with an evaporation window;

[0009] a steel side mold, which can be connected to the support base in combination and can close the two end ports of the cylindrical mold when connected to the base;

[0010] a flexible plastic partition plate arranged in a cylindrical shape and arranged tightly inside the cylindrical mold, and the flexible plastic partition plate is annularly divided into a plastic bottom partition plate and a plastic outer partition plate, wherein the position of the plastic outer partition plate corresponds to the evaporation window on the steel outer film;

[0011] a water-impermeable film covering the inner wall of the pouring chamber surrounded by the flexible plastic partition plate and the steel side mold at both ends.

[0012] The steel bottom film and the steel outer film are spliced to form the cylindrical mold by the cooperation of the clamping groove and the clamping strip.

[0013] A clamping groove perpendicular to the axis of the cylindrical mold is arranged on the support base corresponding to the two ends of the cylindrical mold, and a clamping strip adapted to the clamping groove on the support base is arranged on the steel side mold.

[0014] The cross section of the steel bottom film is a poor arc cross section; and the cross section of the steel outer film is a good arc cross section.

[0015] A lubricant is applied on the inner wall of the pouring chamber.

[0016] The thickness of the flexible plastic partition plate is not more than 2mm.

[0017] The shrinkage mold is vertically arranged, and the lower end thereof is placed on a mold support provided with a supporting ring for supporting the shrinkage mold.

[0018] The center of the steel side mold is provided with a through circular hole.

[0019] The plastic bottom partition plate and the plastic outer partition plate are spliced to form the cylindrical flexible plastic partition plate through the cooperation of the clamping groove and the clamping strip.

[0020] A testing method based on the cement mortar early shrinkage testing device with adjustable evaporation area, characterized in that, comprising:

[0021] 1) preparing a shrinkage mold assembly;

[0022] 2) assembling and erecting the shrinkage mold: placing the steel bottom mold and the supporting base, splicing the steel outer mold and the steel bottom mold into a cylindrical mold, and allowing the shrinkage measuring head to pierce the film along the through circular hole in the center of the steel side mold, and splicing a piece of steel side mold with the shrinkage measuring head and the supporting base, and sealing one end of the cylindrical mold through the steel side mold, and then erecting the shrinkage mold, and placing the end with the installed steel side mold on the mold support, and controlling the shrinkage measuring head to penetrate into the supporting ring;

[0023] 3) pouring and curing the test piece: pouring the cement mortar along the open end of the cylindrical mold, and after filling the mold, splicing another piece of steel side mold with the shrinkage measuring head and the cylindrical mold, and then preparing the setting testing sample, and placing the shrinkage mold together with the support and the setting testing sample into the curing chamber.

[0024] 4) setting time testing: after the cement mortar is formed, the penetration resistance value of the setting testing sample is measured every predetermined time interval, when the penetration resistance value of the sample approaches the preset value, the time interval is shortened, and when the penetration resistance value reaches the preset value, the initial setting time is recorded;

[0025] 5) adjusting the evaporation area of the test piece: when the cement mortar is close to initial setting, the shrinkage mold erected on the mold support is taken down and placed flat, the steel side mold at both ends of the mold is disassembled, and then the steel outer mold is disassembled, the plastic outer partition plate is removed, the evaporation area line is drawn in the evaporation window of the steel outer film, and then the film is lightly drawn along the line with a graver to obtain the evaporation surface of the test piece;

[0026] 6) shrinkage testing: the test piece is moved to the shrinkage testing chamber, and the micrometer is erected at the shrinkage measuring head at both ends of the test piece, and the initial reading of the micrometer is recorded, and then the shrinkage deformation of the test piece is observed to 72h after initial setting.

[0027] The beneficial effects of the utility model are:

[0028] The utility model discloses a steel bottom mould, steel outer mould, steel side mould form the cylindrical retractable mould that can be disassembled, further simplify the formwork removal operation in combination with flexible plastic partition and water -tight film, avoid disturbing test piece in early age stage, and effectively reduce the friction between cylindrical test piece and steel mould, thereby improve the contraction test precision greatly.

[0029] In the utility model, after the plastic outer partition is taken out, the preset size film is drawn on the water -tight film through the evaporation window on the steel outer film, so that the preset size evaporation area is formed quickly.

[0030] The utility model discloses a steel bottom mould, steel outer mould, steel side mould form the cylindrical retractable mould that can be disassembled, further simplify the formwork removal operation in combination with flexible plastic partition and water -tight film, avoid disturbing test piece in early age stage, and effectively reduce the friction between cylindrical test piece and steel mould, thereby improve the contraction test precision greatly.

[0031] The utility model discloses a steel bottom mould, steel outer mould, steel side mould form the cylindrical retractable mould that can be disassembled, further simplify the formwork removal operation in combination with flexible plastic partition and water -tight film, avoid disturbing test piece in early age stage, and effectively reduce the friction between cylindrical test piece and steel mould, thereby improve the contraction test precision greatly. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 It is steel mould assembly schematic diagram of the utility model;

[0033] Figure 2 It is component splicing local schematic diagram of the utility model;

[0034] Figure 3 It is partition and steel mould combination schematic diagram of the utility model;

[0035] Figure 4 It is mould vertical casting top surface schematic diagram of the utility model;

[0036] Figure 5 It is mould vertical casting bottom surface schematic diagram of the utility model;

[0037] Figure 6 It is the appearance schematic diagram of the utility model after pouring mould;

[0038] Figure 7 It is test piece schematic diagram after removing steel outer mould, side mould and outer partition of the utility model;

[0039] Figure 8 Evaporation surface after the shrinkage test schematic diagram is set for the utility model;

[0040] Figure 9 Steel outer mold opening shrinkage mold schematic diagram is set for the utility model;

[0041] Figure 10 Steel outer mold disconnecting structure and shrinkage test schematic diagram is set for the utility model;

[0042] Figure 11 Mold support with fixture schematic diagram is set for the utility model.

[0043] In the drawing: 1, steel bottom mold; 1-1, support base; 2, steel outer mold; 3, steel side mold; 3-1, the center hole of side mold; 4, mold support; 4-1, foot base; 4-2, vertical steel pole; 4-3, horizontal steel pole; 4-4, support steel ring; 5, flexible plastic partition; 5-1, plastic bottom partition; 5-2, plastic outer partition; 6, impermeable film; 7, cylindrical mold; 7-1, inferior arc section; 7-2, superior arc section; 8, clamping groove; 9, shrinkage probe; 10, pouring opening; 11, shrinkage test piece; 12, test piece evaporation surface; 13, micrometer; 14, fixture. DETAILED DESCRIPTION

[0044] In order to better understand the technical scheme of the present application, the embodiments of the present application will be described in detail below with reference to the drawings.

[0045] It should be clear that the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0046] The terms used in the embodiments of the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0047] It should be noted that the "up", "down", "left", "right" and other orientation words described in the embodiments of the present application are described from the angle shown in the drawings, and should not be understood as limiting the embodiments of the present application. In addition, in the context, it is also understood that when referring to an element connected to another element "on" or "under", it can be directly connected to another element "on" or "under" or indirectly connected to another element "on" or "under" through an intermediate element.

[0048] The embodiment 1 is a cement mortar early shrinkage testing device with adjustable evaporation area, which comprises a shrinkage mold and a mold support.

[0049] The shrinkage mold in the embodiment comprises a support base 1-1, a cylindrical mold 7, a steel side mold 3, a flexible plastic partition 5, a water-impermeable film 6, and the like.

[0050] In the embodiment, the cylindrical mold 7 is circumferentially divided into a steel bottom film 1 and a steel outer film 2, the cross section of the steel bottom film is a minor arc cross section 7-1 formed by dividing a cylindrical cross section, the cross section of the steel outer film is a major arc cross section 7-2 formed by dividing the minor arc cross section, and the wall thickness of the minor arc cross section 7-1 of the bottom film and the major arc cross section 7-2 of the outer film is the same. The inner diameter of the cylindrical mold 7 is 40 mm, the outer diameter is 45 mm, the wall thickness is 2.5 mm, the length is 300 mm, the corresponding central angle of the minor arc cross section 7-1 of the bottom film 1 is 120°, and the corresponding central angle of the major arc cross section 7-2 of the outer film 2 is 240°.

[0051] In the embodiment, the cylindrical mold 7 is formed by splicing the steel bottom film 1 and the steel outer film 2 in a detachable connection mode. The detachable splicing of the mold includes bolt connection, clamp connection, latch connection, slot connection or buckle connection, wherein the slot 8 includes a rectangular slot, a T-shaped slot, a circular slot or a V-shaped slot, and is provided with a clamping strip matched with the slot, the slot 8 is arranged at the circumferential two ends of the steel bottom film 1 and is parallel to the axis, and the clamping strip is arranged at the circumferential two ends of the steel outer film 2; the buckle includes a snap buckle, a hoop buckle, a splicing buckle or a pressing buckle.

[0052] In the embodiment, the steel bottom film 1 and the support base 1-1 arranged below it are of an integral structure, the support base 1-1 has a length of 310 mm, a width of 45 mm and a height of 20 mm, and the square side mold 3 has a side length of 45 mm and a wall thickness of 5 mm.

[0053] In the embodiment, the steel outer film 2 is provided with an evaporation window, which is a rectangular window, two long sides of the rectangular window are parallel to the axis of the cylindrical mold 7, and two short sides of the rectangular window are respectively located at the two ends of the steel outer film 2.

[0054] In the embodiment, the steel side mold 3 can be connected with the support base 1-1 and can close the two end ports of the cylindrical mold 7 when connected with the base. The steel side mold 3 is connected through the slot on the clamping strip base, and after splicing with the support base 1-1, the steel side mold 3 is in contact with the two ends of the cylindrical mold 7, and the length of the two pieces of steel side mold 3 after being in contact with the two ends of the cylindrical mold 7 is equal to the length of the support base 1-1.

[0055] The steel side mold 3 is aligned with the center of the cylindrical mold 7 in this embodiment, and a through-hole 3-1 is arranged at the center of the steel side mold 3 for the shrinkage probe 9 extending out of the cylindrical mold 7. The diameter of the through-hole 3-1 is 8 mm, and the through-hole 3-1 and the shrinkage probe 9 are spaced apart by 3 mm in the diameter direction.

[0056] In this embodiment, the flexible plastic partition plate 5 is arranged in a cylindrical shape, which is circumferentially divided into a bottom partition plate 5-1 and an outer partition plate 5-2. The plastic bottom partition plate 5-1 and the outer partition plate 5-2 are arc-shaped plates, and the wall thickness of the plastic arc-shaped plate 5 is 1 mm. The plastic arc-shaped plate 5 is placed on the inner surface of the cylindrical mold 7 during testing and can be seamlessly attached to the inner surface of the cylindrical mold 7. The outer partition plate 5-2 can seal the evaporation window on the steel outer membrane 2.

[0057] In this embodiment, the mold support 4 is composed of a foot base 4-1, four vertical steel rods 4-2, four horizontal steel rods 4-3, and a support circular ring 4-4. One end of each of the four horizontal steel rods 4-3 is fixed to one of the four vertical steel rods 4-2, and the other end is fixed to the support circular ring 4-4. The inner diameter of the support circular ring 4-4 is 45 mm, and the support circular ring 4-4 is arranged in parallel with the foot base 4-1 and is about 130 mm higher than the foot base 4-1. When the shrinkage mold is arranged vertically, the lower end of the shrinkage mold can be supported on the support circular ring 4-4, and the central through-hole of the support circular ring 4-4 can provide installation space for the shrinkage probe 9.

[0058] The testing method of the cement mortar early shrinkage testing device based on adjustable evaporation area in this embodiment includes the following steps:

[0059] 1) Prepare the shrinkage mold assembly: attach the plastic bottom partition plate 5-1 and the outer partition plate 5-2 to the inner surface of the steel bottom mold 1 and the inner surface of the steel outer mold 2, respectively, then apply vaseline lubricant on the exposed surface of the plastic partition plate 5 and the inner surface of the steel side mold 3, and then evenly spread the water-impermeable film 6 on the plastic partition plate 5 and the steel side mold 3;

[0060] 2) Assemble and erect the shrinkage mold: place the steel bottom mold 1 on the support base 1-1, assemble the steel outer mold 2 and the steel bottom mold 1 into the steel cylindrical mold 7 through the sliding clamping slot, and make the shrinkage probe 9 pierce the film 6 along the circular hole 3-1 in the center of the steel side mold 3. Then, assemble the steel side mold 3 with the shrinkage probe 9 and the support base 1-1 through the clamping slot 8, and then erect the shrinkage mold. One end of the steel side mold 3 with the shrinkage probe 9 is mounted on the mold support 4, and the shrinkage probe 9 is inserted into the support circular ring 4-4 of the support 4;

[0061] 3) Pour and cure the test piece 11: pour the cement mortar along the open end of the cylindrical mold 7, and after filling the mold 7, assemble the steel cylindrical mold 7 and the steel side mold 3 with the shrinkage probe 9 through the clamping slot 8, and then prepare the setting test sample. Place the shrinkage mold together with the support 4 and the setting test sample in the curing chamber;

[0062] 4) Setting time test: The penetration resistance value of the setting test sample is measured after the cement mortar is formed, the time interval is 20 min, when the penetration resistance value of the sample approaches 0.3 MPa, the time interval is adjusted to 10 min, and when the penetration resistance value reaches 0.3 MPa, the initial setting time is recorded;

[0063] 5) Evaporation area of the test piece 11: When the cement mortar is close to initial setting, the shrinkage mold standing on the mold support 4 is removed and placed flat, the steel side mold 3 at both ends of the mold is first disassembled, then the steel outer mold 2 is disassembled, the plastic outer partition plate 5-2 is removed, and then the evaporation area line is drawn on the surface of the water-impermeable film 6 along the length direction of the test piece, and then the film 6 is lightly drawn along the line with a knife to obtain the evaporation surface 12 of the cylindrical test piece 11, so as to ensure that the distance from any point on the evaporation surface 12 to the center of the test piece 11 is the same.

[0064] 6) Shrinkage test: The test piece 11 is moved to the shrinkage test chamber, and the micrometer 13 is arranged at the shrinkage measuring head 9 at both ends of the test piece 11, and the initial reading of the micrometer 13 is recorded, and then the shrinkage deformation of the test piece 11 is observed to 72 h after initial setting.

[0065] In order to ensure that the area of the evaporation surface 12 drawn by the knife in step 5) is the preset area, an auxiliary mechanism is installed on the knife in this embodiment, which has a linear guide, a first slider, an arc guide, a second slider and a range limiting slider, etc. The linear guide can be detachably installed on the steel outer mold 2, and the linear guide is arranged parallel to the axis of the cylindrical mold 7, and the first slider is installed on the linear guide. The arc guide is concentrically arranged with the cylindrical mold 7, and one end of the arc guide is fixedly installed on the first slider. The arc guide is provided with an angle scale, and the second slider and the range limiting slider can be installed on the arc guide. The range limiting slider can move along the arc guide on the arc guide and be locked in position by cooperating with the locking mechanism thereon. The second slider can move along the arc guide between the range limiting slider and the first slider on the arc guide.

[0066] In this embodiment, the knife can be installed on the second slider, and when the knife is installed on the second slider, the tip of the knife faces the axis of the cylindrical mold 7.

[0067] In some special cases, the outer partition plate 5-2 cannot be pulled out, and the knife can be used to draw the evaporation surface on the outer partition plate 5-2 and the water-impermeable film 6.

[0068] Example 2: as Figure 9As shown, the difference from Example 1 is that the steel outer mold 2, the outer partition plate 5-2, and the top surface of the water-impermeable film 6 are provided with a pouring opening 10, the side length of the pouring opening 10 is 1 / 3-1 / 2 of the inner diameter of the cylindrical mold 7, the cement mortar is poured through the pouring opening 10, and the pouring opening 10 is sealed with the water-impermeable film after the slurry fills the mold, thereby simplifying the pouring process of the test piece and preparing the shrinkage test piece 11 without using the mold support 4. The cylindrical mold 7 in this example has the same size as that in Example 1, with an inner diameter of 40 mm and an outer diameter of 45 mm, and thus the length x width size of the pouring opening 10 is 20 x 20 mm. Compared with Example 1, this example eliminates the mold support 4, has lower requirements for equipment, and is more convenient to operate, but this example is mainly used for pouring cement mortar with good fluidity to ensure the pouring quality through the self-compaction of the slurry.

[0069] Example 3: as shown, Figure 10 The difference from Example 1 is that the steel outer mold 2 is disconnected along the longitudinal section and is divided into two parts, an evaporation window is formed between the two parts, the outer partition plate 5-2 inside the steel outer mold 2 remains unchanged and is used to support the pouring and forming of the shrinkage test piece 11, the distance between the two outer molds 2 at the break is not greater than the inner diameter of the cylindrical mold 7, the steel side mold 3 is removed after the slurry coagulates, then the outer mold 2 is retained, the outer partition plate 5-2 is directly pulled out, the empty area between the two outer molds 2 is exposed, and then the film 6 of the empty area is drawn by positioning with the outer mold 2 to obtain the evaporation surface of the shrinkage test piece 11. The cylindrical mold 7 in this example has the same size as that in Example 1, with an inner diameter of 40 mm and an outer diameter of 45 mm, and thus the distance between the two outer molds 2 at the break is 25 mm. Compared with Example 1, the mold 7 described in this example is more standardized, the size of the outer mold 2 has a corresponding relationship with the exposed evaporation area of the test piece 11, which is conducive to improving the comparability of the shrinkage test results and improving the accuracy of the shrinkage analysis.

[0070] Example 4: as shown, Figure 11 The difference from Example 1 is that a clamp 14 is arranged at the upper part of the mold support 4 to fix the vertical shrinkage mold, especially when the mold is long, to prevent it from falling due to pouring and improve the stability of the operation. Compared with Example 1, this example is mainly aimed at the slender cylindrical mold 7 with an aspect ratio greater than 8 to ensure the implementability and reliability of the vertical pouring of the test piece 11, meet different shrinkage test requirements, and support the diversification of test types.

Claims

1. A device for testing early-age shrinkage of cement mortar with adjustable evaporative area, characterized in that, The shrinkage mold comprises: a support base; a cylindrical mold, which is annularly divided into a steel bottom film and a steel outer film, wherein the steel bottom film is arranged on the support base, and the steel outer film is provided with evaporation windows; steel side molds, which are connected to the support base in combination and can close the two end ports of the cylindrical mold when connected to the support base; a flexible plastic partition plate arranged in a cylindrical shape and arranged in close contact with the inside of the cylindrical mold, and the flexible plastic partition plate is annularly divided into a plastic bottom partition plate and a plastic outer partition plate, wherein the plastic outer partition plate is located corresponding to the evaporation windows on the steel outer film; a water-impermeable film covering the inner wall of the pouring cavity surrounded by the flexible plastic partition plate and the steel side molds at both ends.

2. The early-age shrinkage of cement paste test device with controllable evaporative area according to claim 1, characterized in that: The steel bottom film and the steel outer film are spliced to form the cylindrical mold by the cooperation of the clamping groove and the clamping strip.

3. The early-age shrinkage of cement paste test device with controllable evaporative area according to claim 1, characterized in that: A clamping groove perpendicular to the axis of the cylindrical mold is arranged on the support base corresponding to the two ends of the cylindrical mold, and a clamping strip adapted to the clamping groove on the support base is arranged on the steel side mold.

4. The early-age shrinkage of cement paste test device with controllable evaporative area according to claim 1, characterized in that: The cross section of the steel bottom film is a poor arc cross section, and the cross section of the steel outer film is a good arc cross section.

5. The early-age shrinkage of cement paste test device with controllable evaporative area according to claim 1, characterized in that: The inner wall of the pouring cavity is coated with a lubricant.

6. The controllable evaporation area early age shrinkage of cement mortar testing device according to claim 1, characterized in that: The thickness of the flexible plastic partition plate is not more than 2 mm.

7. The controllable evaporation area early age shrinkage of cement mortar testing device according to claim 1, characterized in that: The shrinkage mold is vertically arranged, and the lower end thereof is placed on a mold support, which has a supporting ring for supporting the shrinkage mold, and the supporting ring is installed on a support frame.

8. The controllable evaporation area early age shrinkage of cement mortar testing device according to claim 1, characterized in that: A through circular hole is arranged at the center position of the steel side mold.

9. The controllable evaporation area early age shrinkage of cement mortar testing device according to claim 1, characterized in that: The plastic bottom partition plate and the plastic outer partition plate are spliced to form the flexible plastic partition plate in a cylindrical shape by the cooperation of the clamping groove and the clamping strip.

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