A temperature and humidity adjustable cement-based material self-shrinkage deformation measuring device
By introducing heating lamps and humidifiers for temperature and humidity regulation into the self-shrinkage deformation measurement device for cement-based materials, and combining them with dial gauges and camera data acquisition, the problems of existing devices being unable to simulate complex environments and high costs have been solved, achieving efficient and low-cost measurement of self-shrinkage deformation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHANGSHA PUBLIC WORKS CONSTR CENT
- Filing Date
- 2025-04-18
- Publication Date
- 2026-06-02
AI Technical Summary
Existing self-shrinkage deformation measurement devices for cement-based materials lack active temperature and humidity control modules, making it impossible to simulate complex and ever-changing engineering environments. Furthermore, these devices are expensive, complex to operate, and difficult to popularize in small and medium-sized laboratories.
A temperature and humidity adjustable self-shrinkage deformation measurement device for cement-based materials was designed. It uses heating lamps and humidifiers for active temperature and humidity regulation, combined with a transparent acrylic box, temperature and humidity probes, and a dial indicator and a rechargeable camera for data acquisition, simplifying the operation process and reducing costs.
It achieves active temperature and humidity regulation and high-precision measurement, significantly reduces equipment costs, simplifies operation procedures, supports unattended monitoring, and obtains continuous temperature and humidity-shrinkage deformation relationship curves.
Smart Images
Figure CN224317558U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of civil engineering materials technology, specifically a temperature and humidity adjustable cement-based material self-shrinkage deformation measuring device. Background Technology
[0002] The autogenous shrinkage deformation of cement-based materials (such as ultra-high performance concrete, UHPC) during the hardening process is a key factor initiating internal microcracks and leading to strength degradation. With the widespread application of high-strength concrete in engineering, accurately measuring the autogenous shrinkage deformation under different temperature and humidity conditions has become an important research topic for optimizing material mix proportions and improving structural durability.
[0003] Traditional methods for measuring self-shrinkage often rely on constant temperature and humidity laboratory environments combined with manual recording by a measuring mechanism, which suffers from problems such as limited environmental conditions and low data acquisition efficiency. In recent years, Chinese patent CN214845281U proposed a one-piece concrete corrugated pipe testing device, which achieves automatic data acquisition through parallel testing instruments and displacement sensors, significantly improving testing efficiency.
[0004] However, this technology still has significant limitations:
[0005] 1. The device lacks an active temperature and humidity control module, which cannot simulate the complex and ever-changing environmental conditions in actual engineering, resulting in deviations between the test data and the actual working conditions; the environmental parameter control and deformation measurement systems are independent of each other, making it difficult to achieve synchronous and precise control and correlation analysis of temperature, humidity and shrinkage deformation.
[0006] 2. Reliance on high-precision displacement sensors and supporting data acquisition systems results in high equipment costs. Furthermore, sensors exposed to high humidity environments for extended periods are prone to drift, affecting measurement stability. The use of precision electronic components in pursuit of automation increases device costs and complicates operating procedures, limiting the widespread application of this technology in small and medium-sized laboratories. Utility Model Content
[0007] The purpose of this invention is to provide a temperature and humidity adjustable self-shrinkage deformation measuring device for cement-based materials that is easy to operate, low in cost, and highly accurate.
[0008] This utility model provides a temperature and humidity adjustable self-shrinkage deformation measuring device for cement-based materials, comprising an environmental simulation chamber, a self-shrinkage test component, and a monitoring component. The environmental simulation chamber includes a sealed enclosure with temperature and humidity control functions, and a temperature probe and a humidity probe are installed inside the enclosure. The self-shrinkage test component includes a non-expansion material support frame installed inside the enclosure, at least one set of horizontally placed corrugated pipe specimens, a screw adjustment mechanism connected to the end of the corrugated pipe specimens, and a displacement measuring gauge in contact with the other end of the corrugated pipe specimens. The monitoring component includes an image acquisition device positioned directly opposite the displacement measuring gauge. The screw adjustment mechanism includes a screw fixedly connected to the corrugated pipe specimens and a nut threadedly engaged with the support frame, and the end of the measuring rod of the displacement measuring gauge maintains contact and limitation with the end cap of the corrugated pipe specimen.
[0009] In one embodiment of the above-mentioned device, the support frame includes two vertically arranged steel plates, and multiple sets of horizontal connecting rods are provided between the two steel plates. The corrugated pipe specimen is placed on two connecting rods of the same set.
[0010] In one embodiment of the above-mentioned device, a heating lamp is provided on the top of the box, and a humidifier is provided on the side wall of the box.
[0011] In one embodiment of the above-described device, the support frame, screw, and nut are made of ferritic stainless steel.
[0012] In one embodiment of the above-mentioned device, the side wall of the housing is provided with an opening that matches the side plate of the support frame, and the dial portion of the mechanical displacement measuring instrument extends out of the outside of the housing.
[0013] In one embodiment of the above-described device, the image acquisition device is a rechargeable camera with a built-in storage battery.
[0014] In one embodiment of the above-mentioned device, the displacement measuring instrument is a dial gauge, and each dial gauge is set up in a one-to-one correspondence with the corrugated pipe specimen.
[0015] In one embodiment of the above-mentioned device, the horizontal connecting rods are provided in three sets, each set containing two parallel rods, and each set of rods corresponds to supporting one corrugated pipe specimen.
[0016] In one embodiment of the above-mentioned device, the chamber is made of transparent acrylic sheet, and the temperature probe and humidity probe are set in close contact with the corrugated pipe specimen.
[0017] In one embodiment of the above-described device, the nut is rotatably connected to the side plate of the support frame via a bearing.
[0018] The beneficial effects of this utility model are as follows:
[0019] 1. It integrates adjustable temperature and humidity environment with high-precision measurement functions; it achieves active temperature and humidity adjustment through built-in heating lamps and humidifiers, and monitors environmental parameters in real time with temperature and humidity probes; it adopts direct contact measurement between dial indicator and specimen, combined with non-expansion steel frame and screw, effectively eliminating measurement errors caused by thermal expansion of metal parts;
[0020] 2. Significantly reduces equipment costs and simplifies operation procedures; the use of a dial indicator to replace the high-precision displacement sensor, combined with the housing and non-expansion stainless steel components, greatly reduces the cost of the device; the specimen positioning can be completed by rotating the nut to adjust the screw, and with the end cap, the specimen can be quickly installed and sealed, and operators can complete the test preparation without professional training;
[0021] 3. Enables unattended monitoring; continuously captures readings through a rechargeable camera facing the dial, and with the built-in battery ensuring continuous recording for 24 hours after power failure, replacing manual meter reading; environmental parameters and deformation data are collected simultaneously, and complete and continuous temperature, humidity and shrinkage deformation relationship curves can be obtained without human intervention during the test. Attached Figure Description
[0022] Figure 1 This is a schematic diagram of the overall structure of one embodiment of the present utility model.
[0023] Figure 2 for Figure 1 A schematic diagram of the structure of the medium-environment simulation chamber.
[0024] Figure 3 for Figure 1 A schematic diagram of the structure of a parallel self-shrinking device.
[0025] Explanation of reference numerals in the attached figures:
[0026] 1. Environmental simulation chamber, 11. Chamber body, 12. Heating lamp, 13. Humidifier, 14. Temperature probe, 15. Humidity probe; 2. Self-shrinkage test assembly, 21. Steel frame, 22. Corrugated pipe, 23. Screw, 24. Nut, 25. Dial gauge; 3. Monitoring assembly. Detailed Implementation
[0027] The relevant technical solutions will now be clearly and completely described with reference to the accompanying drawings of the embodiments of this utility model. Obviously, the described embodiments are only a part of the embodiments, and not all of the embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this utility model.
[0028] like Figures 1 to 3As shown, the temperature and humidity adjustable cement-based material self-shrinkage deformation measuring device disclosed in this embodiment includes an environmental simulation chamber 1, a self-shrinkage test component 2, and a monitoring component 3.
[0029] The self-shrinkage test assembly 2 is placed inside the environmental simulation chamber 1, and the data acquisition and monitoring assembly 3 is fixed directly above the self-shrinkage test assembly.
[0030] The environmental simulation chamber 1 includes a chamber body 11, a heating lamp 12, a humidifier 13, a temperature probe 14, and a humidity probe 15.
[0031] The box 11 is a rectangular box made of transparent acrylic sheet. A heating lamp 12 is installed on the top surface inside the box, and a humidifier 13 is installed on the side. A panel is set on the box to control the heating lamp and humidifier inside the box, so that the environmental conditions can be adjusted.
[0032] Temperature probe 14 and humidity probe 15 are installed inside the chamber and fixed near the self-shrink test component 2 to monitor the temperature and humidity of the environment in which the test specimen is located in real time.
[0033] The self-shrinkage test assembly 2 includes a steel frame 21, a bellows 22, a screw 23, a nut 24, and a dial indicator 25.
[0034] The steel frame 21 includes two vertically arranged steel plates facing each other, with multiple sets of horizontal connecting rods evenly spaced between the two steel plates. Each set of connecting rods consists of two rods. In this embodiment, three sets are provided.
[0035] One bellows 22 is placed on a set of connecting rods. Both ends of each bellows are sealed with bellows heads of the appropriate size to ensure that the specimen is isolated from the outside environment, prevent moisture exchange, and ensure test accuracy.
[0036] One end cap of each bellows 22 is fixedly connected to a screw 23; holes are opened on the corresponding side of the steel plate of the steel frame 21, and nuts 24 are rotatably connected to the inside of the holes via bearings. The screws of the bellows are threadedly connected to the nuts, and the relative position between the bellows and the steel frame can be adjusted by rotating the nuts.
[0037] Multiple dial indicators 25 are fixedly installed on the other side of the steel frame 21, with each dial indicator corresponding to a bellows 22. The end of the dial indicator's measuring rod contacts the bellows end cap, holding the bellows in place and limiting its movement. This is used to measure the displacement changes caused by the shrinkage or expansion of the specimen.
[0038] The side of the enclosure 11 has a pre-drilled opening that matches the dimensions of the side panel of the steel frame 21, allowing the dial indicator 25 to extend outside the enclosure. This facilitates monitoring and recording of the dial indicator data and also prevents the dial indicator from being damaged by changes in temperature and humidity inside the enclosure.
[0039] The steel frame 21, screw 23 and nut 24 are made of non-expansion stainless steel, such as ferritic stainless steel of grade 430, to ensure structural stability and corrosion resistance, and to avoid errors caused by temperature effects on the steel frame and screw during the experiment.
[0040] Monitoring component 3 includes a camera and its built-in battery. The camera is located directly above the dial indicator 25 and records the dial indicator readings in real time, enabling automatic data acquisition. The built-in battery module allows for 24 hours of continuous operation after a power outage, ensuring experimental continuity.
[0041] The steps for measuring the autogenous shrinkage deformation of cement-based materials using this device are as follows:
[0042] 1. Specimen preparation and installation:
[0043] Pour the freshly mixed cement-based material into the corrugated pipe. During pouring, use a vibrating table to fully compact the material and remove internal air bubbles. Immediately seal both ends with corrugated pipe end caps of matching size to form a sealed specimen. Quickly place the sealed corrugated pipe specimen horizontally on the two connecting rods of the same group on the steel frame, ensuring that the axis of the corrugated pipe is aligned with the dial indicator rod. Rotate the nut at the fixed end of the corrugated pipe and adjust the relative position of the corrugated pipe and the steel frame through the screw, so that the end cap at the other end of the specimen is in close contact with the dial indicator rod.
[0044] 2. Environmental parameter setting and monitoring:
[0045] Set the target temperature and humidity values through the panel of the environmental simulation chamber, and turn on the heating lamp and humidifier; fix the temperature probe and humidity probe near the corrugated pipe specimen to provide real-time feedback on the environmental data inside the chamber; close the chamber and ensure that the dial gauge dial is exposed to the outside of the chamber through the reserved opening;
[0046] 3. Data acquisition system debugging:
[0047] Ensure the camera is directly facing the dial indicator and can clearly capture the readings; reset each dial indicator to zero and record the initial timestamp; activate the camera's built-in battery to ensure continuous data recording for 24 hours after power failure.
[0048] 4. Continuous measurement and data extraction:
[0049] The experiment continuously captures images of the dial of a dial indicator using a camera to record displacement changes caused by the shrinkage / expansion of the specimen; these changes are then viewed in real time on an external device; after the experiment, the correlation between environmental parameters and self-shrinkage deformation is analyzed by combining monitoring data from temperature and humidity probes.
[0050] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A temperature and humidity adjustable device for measuring the self-shrinkage deformation of cement-based materials, characterized in that: It includes an environmental simulation chamber, a self-shrinkage test assembly, and a monitoring assembly; The environmental simulation chamber includes a sealed chamber with temperature and humidity control functions, and the chamber is equipped with a temperature probe and a humidity probe. The self-shrinkage test assembly includes a non-expansion material support frame disposed inside a chamber, at least one set of horizontally placed bellows specimens, a screw adjustment mechanism connected to one end of the bellows specimens, and a displacement measuring gauge in contact with the other end of the bellows specimens. The monitoring component includes an image acquisition device positioned directly opposite the displacement measurement meter; The screw adjustment mechanism includes a screw fixedly connected to the bellows specimen and a nut threadedly engaged with the support frame. The end of the measuring rod of the displacement gauge is kept in contact with the end cap of the bellows specimen for limiting.
2. The temperature and humidity adjustable cement-based material self-shrinkage deformation measuring device as described in claim 1, characterized in that: The support frame comprises two vertical steel plates arranged opposite each other, with multiple sets of horizontal connecting rods between the two steel plates, and the corrugated pipe specimen is placed on the two connecting rods in the same set.
3. The temperature and humidity adjustable cement-based material self-shrinkage deformation measuring device as described in claim 1, characterized in that: The top of the chamber is equipped with a heating lamp, and the side wall of the chamber is equipped with a humidifier.
4. The temperature and humidity adjustable cement-based material self-shrinkage deformation measuring device as described in claim 1, characterized in that: The support frame, screw, and nut are made of ferritic stainless steel.
5. The temperature and humidity controlled cementitious material autoshrinkage deformation measuring device of claim 1, wherein: The side wall of the box is provided with an opening that matches the side plate of the support frame, and the dial of the displacement measuring instrument extends out of the outside of the box.
6. The temperature and humidity adjustable cement-based material self-shrinkage deformation measuring device as described in claim 1, characterized in that: The image acquisition device is a rechargeable camera with a built-in battery.
7. The temperature and humidity adjustable cement-based material self-shrinkage deformation measuring device as described in claim 1, characterized in that: The displacement measuring instruments are dial gauges, and each dial gauge is set up in a one-to-one correspondence with the corrugated pipe specimen.
8. The temperature and humidity adjustable cement-based material self-shrinkage deformation measuring device as described in claim 2, characterized in that: The horizontal connecting rods are provided in three sets, each set containing two parallel rods, and each set of rods corresponds to supporting one corrugated pipe specimen.
9. The temperature and humidity adjustable cement-based material self-shrinkage deformation measuring device as described in claim 1, characterized in that: The enclosure is made of transparent acrylic sheet, and the temperature probe and humidity probe are set in close contact with the corrugated pipe specimen.
10. The temperature and humidity adjustable self-shrinkage deformation measuring device for cement-based materials as described in claim 1, characterized in that: The nut is rotatably connected to the side plate of the support frame via a bearing.