Cement-based sensing material, and preparation method and application thereof

Abstract

This invention discloses a cement-based sensing material, its preparation method, and its applications. The cement-based sensing material of this invention comprises the following components in parts by weight: cementitious material: 100 parts; porous aggregate: 50-300 parts; sensing functional particles: 1-3 parts; water-reducing agent: 0.3-4 parts; the sensing functional particles consist of a hydrogel polymer and conductive fillers. The preparation method of the cement-based sensing material of this invention includes the following steps: mixing the cementitious material, porous aggregate, sensing functional particles, water-reducing agent, and water evenly, followed by molding and curing. The cement-based sensing material of this invention has advantages such as good structural compatibility, high moisture sensitivity, excellent electrical response stability, and good long-term service stability. It is suitable for monitoring seepage risks in hydraulic structures, and its preparation method is simple and has low production costs, making it suitable for prefabrication and large-scale engineering applications.

Description

Technical Field

[0001] This invention relates to the field of hydraulic structure health monitoring technology, specifically to a cement-based sensing material, its preparation method, and its application. Background Technology

[0002] Seepage is a common and significant risk factor for hydraulic structures during long-term service. In earth-rock dams, concrete dams, gate piers, construction joints, contact zones, and weak points in the anti-seepage system, localized abnormal seepage often leads to increased pore water migration, fine particle loss, and the gradual development of seepage channels. In severe cases, it can further induce problems such as piping, seepage failure, and local instability. Therefore, long-term, continuous, and early monitoring of seepage risks in hydraulic structures is of great importance.

[0003] Currently, seepage monitoring of hydraulic structures mainly employs techniques such as piezometer monitoring, flow meter monitoring, fiber optic sensing monitoring, and resistivity tomography monitoring. However, these techniques all have significant drawbacks, specifically: Piezometer and flow meter monitoring are mostly point-based methods with limited monitoring range, making it difficult to promptly reflect early-stage abnormal seepage; while fiber optic monitoring technologies have high sensitivity, they have high requirements for encapsulation methods, installation conditions, and construction environment, and the system structure is relatively complex and costly; resistivity tomography technology typically relies on external electrode arrays and subsequent inversion analysis, and it is difficult to form small-scale, embedded long-term monitoring units suitable for internal structures.

[0004] Studies have shown that one of the most direct material-level changes when a hydraulic structure experiences seepage risk is the abnormal alteration of its local water content. Therefore, if a conductive cement-based sensing material with a significant electrical response to changes in water content, good compatibility with the hydraulic structure's bulk material, and suitability for long-term burial could be developed, it would be possible to directly monitor seepage risk. However, existing conductive cement-based sensing materials typically construct conductive networks by incorporating conductive phases such as carbon fibers, graphite, and carbon black, and utilize changes in resistivity for sensing. When used for seepage monitoring, these materials suffer from problems such as difficulty in dispersing conductive components, insufficient stability of the conductive network, insignificant response to local water content changes, and limited water migration efficiency, making it difficult to fully meet practical application requirements.

[0005] Therefore, it is of great significance to develop a cement-based sensing material that has strong responsiveness to changes in the local water content of hydraulic structures, good long-term service stability, and is suitable for monitoring seepage risks in hydraulic structures. Summary of the Invention

[0006] The purpose of this invention is to provide a cement-based sensing material, its preparation method, and its application.

[0007] The technical solution adopted in this invention is: A cement-based sensing material comprising the following components in parts by weight: Cementitious material: 100 parts; Porous aggregate: 50 parts to 300 parts; Sensing functional particles: 1 to 3 parts; Water-reducing agent: 0.3 to 4 parts; The sensing functional particles are composed of hydrogel polymers and conductive fillers.

[0008] Preferably, the cementing material is at least one of ordinary Portland cement, Portland cement, slag Portland cement, and fly ash Portland cement; or, the cementing material is a mixture of at least one of ordinary Portland cement, Portland cement, slag Portland cement, and fly ash Portland cement with at least one of fly ash, granulated blast furnace slag powder, silica fume, and limestone powder.

[0009] Preferably, the porous aggregate is at least one of porous ceramsite, porous glass particles, and porous mineral particles.

[0010] Preferably, the porous aggregate has a particle size of 0.5 mm to 10 mm.

[0011] Preferably, the hydrogel polymer in the sensing functional particles is at least one of polyacrylamide, polyacrylic acid, and acrylamide-acrylic acid copolymer.

[0012] Preferably, the conductive filler in the sensing functional particles is at least one of graphite, polypyrrole particles, and carbon black.

[0013] Preferably, the particle size of the conductive filler in the sensing functional particles is 2μm to 10μm.

[0014] Preferably, the particle size of the sensing functional particles is 10μm to 40μm.

[0015] Preferably, the sensing functional particles are prepared by a method comprising the following steps: mixing monomers, crosslinking agents, initiators, accelerators, conductive fillers and surfactants for polymerization reaction, followed by freeze drying and pulverization to obtain sensing functional particles.

[0016] Preferably, the mass ratio of the monomer to the conductive filler is 1:0.05 to 0.15.

[0017] Preferably, the mass ratio of the monomer, crosslinking agent, initiator, and accelerator is 1:0.005~0.03:0.002~0.02:0.0005~0.01.

[0018] Preferably, the crosslinking agent is at least one of N,N′-methylenebisacrylamide and polyethylene glycol diacrylate.

[0019] Preferably, the initiator is at least one of potassium persulfate and ammonium persulfate.

[0020] Preferably, the accelerator is at least one of N,N,N′,N′-tetramethylethylenediamine and sodium bisulfite.

[0021] Preferably, the mass ratio of the conductive filler to the surfactant is 1:0.005 to 0.1.

[0022] Preferably, the surfactant is at least one of sodium dodecyl sulfate and hexadecyltrimethylammonium bromide.

[0023] Preferably, the polymerization reaction is carried out at a temperature of 40°C to 70°C for a reaction time of 0.5 h to 3 h.

[0024] Preferably, the water-reducing agent is a polycarboxylate water-reducing agent.

[0025] Preferably, the resistivity of the cement-based sensing material is 24.9 Ω·m to 33.1 Ω·m at a moisture content of 70%, and 10 Ω·m to 18 Ω·m at a moisture content of 100%, with a moisture sensitivity ≥40% and a characteristic response time t. 90 ≤10min.

[0026] Preferably, the cement-based sensing material maintains good response stability and reusability under wet-dry cycling conditions, wherein the stability coefficient of the 10th cycle is 95% to 105% and the baseline drift rate is ≤15%.

[0027] A method for preparing a cement-based sensing material as described above includes the following steps: The cementitious material, porous aggregate, sensing functional particles, water-reducing agent and water are mixed evenly, and then molded and cured to obtain cement-based sensing material.

[0028] Preferably, the mass ratio of the cementitious material to water is 1:0.3 to 0.5.

[0029] A cement-based sensor comprising the aforementioned cement-based sensing material.

[0030] An application of a cement-based sensing material as described above for health monitoring of hydraulic structures.

[0031] The principle of this invention: This invention introduces porous aggregates and sensing functional particles into a cement matrix. The porous aggregates accelerate moisture migration, amplifying the moisture exchange between the monitored concrete and the cement-based sensing material, thereby improving the moisture content sensing sensitivity of the cement-based sensing material. Simultaneously, the sensing functional particles, composed of hydrogel polymers and conductive fillers, form a moisture-sensitive conductive network within the cement matrix. When seepage occurs in the hydraulic structure, causing a change in local moisture content, moisture migrates into the cement-based sensing material through the pores of the porous aggregates and cement matrix. This causes changes in the structural state and conductive pathways of the sensing functional particles, ultimately resulting in a change in the resistivity of the cement-based sensing material, thus enabling the monitoring of seepage risks in hydraulic structures.

[0032] The beneficial effects of the present invention are: the cement-based sensing material of the present invention has the advantages of good structural compatibility, high moisture sensitivity, excellent electrical response stability and good long-term service stability, and is suitable for seepage risk monitoring of hydraulic structures. Moreover, its preparation method is simple and the production cost is low, making it suitable for prefabrication and large-scale engineering applications.

[0033] Specifically: 1) The cement-based sensing material of the present invention has good compatibility with the hydraulic structure body material in terms of composition and service environment, and is suitable for long-term burial. 2) The porous aggregate in the cement-based sensing material of the present invention can promote the migration of external moisture into the interior of the cement-based sensing material and can amplify the local water content changes caused by seepage, thereby improving the ability to perceive seepage risks. 3) The sensing functional particles in the cement-based sensing material of the present invention can form a moisture-sensitive conductive network in the cement matrix, thereby enabling the cement-based sensing material to produce a significant resistivity response to abnormal moisture intrusion. 4) The cement-based sensing material of the present invention has a stable basic resistivity after standard curing and under different moisture content control conditions, can produce obvious response to changes in external moisture, and can maintain good response stability and reusability under dry and wet cycle conditions. 5) The preparation process of the cement-based sensing material of the present invention is simple, and it is easy to achieve small-size prefabrication, which facilitates embedded deployment in construction joints, contact zones, seepage-sensitive areas and other locations. Detailed Implementation

[0034] The present invention will be further explained and described below with reference to specific embodiments.

[0035] Example 1: A cement-based sensing material, the composition of which is shown in the table below: Table 1. Composition of a cement-based sensing material

[0036] Note: The preparation method of the sensing functional particles is as follows: Acrylamide, N,N′-methylenebisacrylamide, potassium persulfate, N,N,N′,N′-tetramethylethylenediamine, graphite (particle size of 2μm to 10μm) and sodium dodecyl sulfate are stirred and mixed evenly. The mass ratio of acrylamide to graphite is 1:0.1, the mass ratio of acrylamide, N,N′-methylenebisacrylamide, potassium persulfate, and N,N,N′,N′-tetramethylethylenediamine is 1:0.01:0.01:0.001, and the mass ratio of graphite to sodium dodecyl sulfate is 1:0.02. The mixture is then reacted at 55℃ for 1.5h, followed by freeze drying and pulverization to obtain the sensing functional particles.

[0037] The preparation method of the above-mentioned cement-based sensing material is as follows: Ordinary silicate cement, pumice particles, and sensing functional particles are mixed evenly. Then, polycarboxylate superplasticizer is dissolved in water and added to the system. The mass ratio of ordinary silicate cement to water is 1:0.4. The mixture is stirred evenly to form a paste. The paste is then poured into a mold for molding. After demolding, it is cured according to standard to obtain cement-based sensing material (size 1cm×1cm×6cm).

[0038] Example 2: A cement-based sensing material, the composition of which is shown in the table below: Table 2 Composition of a cement-based sensing material

[0039] Note: The preparation method of the sensing functional particles is as follows: Acrylamide, N,N′-methylenebisacrylamide, potassium persulfate, N,N,N′,N′-tetramethylethylenediamine, polypyrrole particles (particle size of 2μm to 10μm) and sodium dodecyl sulfate are stirred and mixed evenly. The mass ratio of acrylamide to polypyrrole particles is 1:0.12, the mass ratio of acrylamide, N,N′-methylenebisacrylamide, potassium persulfate, and N,N,N′,N′-tetramethylethylenediamine is 1:0.015:0.01:0.0015, and the mass ratio of polypyrrole particles to sodium dodecyl sulfate is 1:0.03. The mixture is then reacted at 55℃ for 1.5h, followed by freeze drying and pulverization to obtain the sensing functional particles.

[0040] The preparation method of the above-mentioned cement-based sensing material is as follows: Ordinary silicate cement, fly ash, porous ceramsite, and sensing functional particles are mixed evenly. Then, polycarboxylate superplasticizer is dissolved in water and added to the system. The ratio of the total mass of ordinary silicate cement and fly ash to the mass of water is 1:0.42. The mixture is stirred evenly to form a paste. The paste is then poured into a mold for molding. After demolding, it is cured according to standard to obtain cement-based sensing material (size 1cm×1cm×6cm).

[0041] Example 3: A cement-based sensing material, the composition of which is shown in the table below: Table 3 Composition of a cement-based sensing material

[0042] Note: The preparation method of the sensing functional particles is as follows: Acrylamide, N,N′-methylenebisacrylamide, potassium persulfate, N,N,N′,N′-tetramethylethylenediamine, carbon black (particle size of 2μm to 10μm) and sodium dodecyl sulfate are stirred and mixed evenly. The mass ratio of acrylamide to carbon black is 1:0.15, the mass ratio of acrylamide, N,N′-methylenebisacrylamide, potassium persulfate, and N,N,N′,N′-tetramethylethylenediamine is 1:0.02:0.012:0.002, and the mass ratio of carbon black to sodium dodecyl sulfate is 1:0.05. The mixture is then reacted at 55℃ for 1.5h, followed by freeze drying and pulverization to obtain the sensing functional particles.

[0043] The preparation method of the above-mentioned cement-based sensing material is as follows: Ordinary silicate cement, slag powder, porous glass particles, and sensing functional particles are mixed evenly. Then, polycarboxylate superplasticizer is dissolved in water and added to the system. The ratio of the total mass of ordinary silicate cement and slag powder to the mass of water is 1:0.42. The mixture is stirred evenly to form a paste. The paste is then poured into a mold for molding. After demolding, it is cured according to standard to obtain cement-based sensing material (size 1cm×1cm×6cm).

[0044] Comparative Example 1: A cement-based sensing material is identical to the cement-based sensing material of Example 1, except that it does not contain sensing functional particles.

[0045] Comparative Example 2: A cement-based sensing material is identical to the cement-based sensing material of Example 1, except that it does not contain pumice particles.

[0046] Comparative Example 3: A cement-based sensing material is identical to the cement-based sensing material of Example 1, except that the "sensing functional particles" are replaced with "hydrogel polymer particles".

[0047] Note: The preparation method of hydrogel polymer particles is as follows: Acrylamide, N,N′-methylenebisacrylamide, potassium persulfate and N,N,N′,N′-tetramethylethylenediamine are stirred and mixed evenly. The mass ratio of acrylamide, N,N′-methylenebisacrylamide, potassium persulfate and N,N,N′,N′-tetramethylethylenediamine is 1:0.02:0.012:0.002. The mixture is then reacted at 55℃ for 1.5 h, followed by freeze drying and pulverization to obtain hydrogel polymer particles.

[0048] Performance testing: 1) Performance testing methods: a) Moisture content control test: After curing, the specimen (cement-based sensing material with dimensions of 1cm×1cm×6cm) was placed in a drying oven and dried at 40℃~60℃ until constant weight. The constant weight was recorded as m. d Then, the specimen is soaked with water until it is internally saturated and the surface is wiped dry with no visible free water. The saturated mass is recorded as m. s Then, the specimen mass is adjusted to the target m by controlling the drying time or constant humidity environment. t The moisture content is calculated using the following formula: W = (m t -m d ) / (m s -m d )×100%, where W is the moisture content of the specimen, m d m is the mass of the specimen after drying to constant weight. s Let m be the mass of the specimen when it is internally saturated with water and has no free water on its surface. t The quality of the specimen under the target test conditions was determined. Conditions with 100% moisture content and 70% moisture content were set to simulate high water content seepage and normal service conditions, respectively. b) Resistivity testing under different moisture contents: The specimens were adjusted to 70% and 100% moisture contents respectively, and the quality was kept stable. The resistance of the specimens was then measured using an electrochemical workstation, and the resistivity was calculated based on the specimen dimensions. The resistivity was calculated using the following formula: ρ = R × A / L, where ρ is the resistivity, R is the resistance, A is the cross-sectional area of ​​the specimen, and L is the effective length in the test direction. The resistivity at 70% moisture content is used to characterize the basic electrical properties of cement-based sensing materials under normal service conditions and serves as a reference baseline for judging seepage anomalies. The resistivity at 100% moisture content is used to characterize the electrical performance of cement-based sensing materials under high moisture content conditions. c) Moisture sensitivity test: Measure the resistivity of the specimen at 70% and 100% moisture content respectively, and calculate the moisture sensitivity using the following formula: =(ρ 70 -ρ 100 ) / ρ 70 ×100%, where, For moisture sensitivity, ρ 70 ρ is the resistivity of the specimen at 70% moisture content. 100 The resistivity of the specimen at 100% moisture content is given. Moisture sensitivity is used to characterize the ability of cement-based sensing materials to distinguish between different moisture states. The higher the value, the more sensitive the cement-based sensing material is to changes in moisture state, and the better it is for identifying local moisture anomalies caused by seepage in hydraulic structures. d) Characteristic response time t 90 Test: During the process of the specimen switching from one stable moisture content state to another, the change in resistance was recorded in real time, and the rate of change of resistance was calculated using the following formula: R / R0=(R t -R0) / R0×100%, where, R / R0 is the rate of change of resistance, where R0 is the resistance in the initial steady state, and R... t Let be the resistance at time t. The time when the rate of change of resistance reaches 90% of its final stable value is defined as the characteristic response time t. 90 ,Right now:( R / R0)t 90 =0.9×( R / R0)∞, where, ( R / R0)∞ is the final steady-state resistance change rate. t 90 The smaller the value, the faster the cement-based sensing material responds to changes in the external moisture content. e) Wet-dry cycle stability test: The specimen was subjected to multiple cycles between 70% and 100% moisture content, and the response amplitude between the two moisture contents was recorded in each cycle. The cycle stability coefficient S of the nth cycle was determined. n Calculate S using the following formula: n =|( R / R0) n | / |( R / R0)1|×100%, where S n Let be the cycle stability coefficient for the nth cycle, ( R / R0)1 is the magnitude of the rate of change of resistance in the first cycle, ( R / R0) nThis represents the magnitude of the rate of change of resistance in the nth cycle. The closer the cyclic stability coefficient is to 100%, the better the response stability of the cement-based sensing material under repeated wet-dry cycling conditions. f) Baseline drift rate test: Record the baseline resistivity at 70% moisture content at the start of each cycle, using the initial resistivity of the first cycle as a reference. The baseline drift rate is calculated using the following formula: D n =|ρ 0,n -ρ 0,1 | / |ρ 0,1 |×100%, where D n Let ρ be the baseline drift rate in the nth cycle. 0,1 The baseline resistivity at the start of the first cycle, ρ 0,n The baseline resistivity is the starting value for the nth cycle. A smaller baseline drift rate indicates better baseline stability of the cement-based sensing material during long-term repeated use.

[0049] 2) Performance test results and analysis: The performance test data of the cement-based sensing materials of Examples 1-3 and Comparative Examples 1-3 are shown in the table below: Table 4 Performance test data of cement-based sensing materials

[0050] As shown in Table 4: a) The cement-based sensing materials of Examples 1-3 have a relatively stable basic resistivity at 70% moisture content, while the resistivity is significantly reduced at 100% moisture content, indicating that they can produce a significant electrical response to changes in moisture content caused by external moisture intrusion. (b) The cement-based sensing material of Example 1 contains both porous aggregate and sensing functional particles, and the sensing functional particles contain conductive fillers, thus forming a relatively complete moisture-sensitive conductive network system. The resistivity of the cement-based sensing material of Example 1 is 33.1 Ω·m at 70% moisture content and 14.0 Ω·m at 100% moisture content, with a moisture sensitivity of 57.7%, indicating that it has a good ability to distinguish state changes caused by increased moisture content. Meanwhile, its t 90 The response time is 7.8 minutes, indicating that it has a relatively fast response speed; c) The cement-based sensing material in Example 2 appropriately increased the amount of porous aggregate and sensing functional particles, and used polypyrrole particles as conductive fillers. Its resistivity was 28.6 Ω·m at 70% moisture content and 11.7 Ω·m at 100% moisture content, achieving a moisture sensitivity of 59.1%. 90The response time was 5.8 min, which showed better performance in terms of distinguishing water content and response rate. This indicates that under the formulation conditions of this embodiment, a higher amount of porous aggregate and sensing functional particles is beneficial to improving the response ability of cement-based sensing materials to changes in water content. d) The dosage of sensing functional particles in the cement-based sensing material of Example 3 was further increased, and its basic resistivity was further reduced, but its moisture sensitivity decreased to 47.8%, and t 90 The increase to 8.9 min indicates that when the dosage of sensing functional particles is high and there are many conductive pathways, the relative electrical differences under different water content states may be weakened, which is not conducive to further improving the ability of cement-based sensing materials to identify changes in water content. e) In Comparative Example 1, the cement-based sensing material did not introduce sensing functional particles, relying solely on the cement matrix and porous aggregate. It exhibited high resistivity at both 70% and 100% moisture content, and its moisture sensitivity was only 17.8%. 90 The response time of 18.6 minutes indicates that relying solely on porous structures is insufficient to form an effective moisture-sensitive conductive network, resulting in a small response amplitude and slow response speed to changes in water content. Although the baseline drift rate of the cement-based sensing material in Comparative Example 1 is small, its overall resistivity is high, its moisture sensitivity is low, and its response speed is slow. This suggests that its small baseline drift mainly stems from its overall insensitivity to changes in water content and does not necessarily indicate superior seepage monitoring performance. f) No porous aggregate was introduced into the cement-based sensing material of Comparative Example 2. Although it has a certain electrical response capability due to the presence of sensing functional particles, its moisture sensitivity and response speed are lower than those of the cement-based sensing material of Example 1. This indicates that porous aggregate plays an important role in promoting the rapid migration of external moisture into the interior of the cement-based sensing material and amplifying the influence of moisture content changes. g) The cement-based sensing material of Comparative Example 3 does not contain conductive fillers, but only hydrogel polymers. Its moisture sensitivity and cycling stability are lower than those of the cement-based sensing material of Example 1, and t 90 The relatively large value indicates that conductive fillers are of great significance for forming a stable and continuous conductive network, improving the response capability of cement-based sensing materials to changes in water content, and maintaining the ability to retain cyclic response.

[0051] It is evident that the cement-based sensing material in Comparative Example 1 lacks sensing functional particles, making it difficult to form an effective moisture-sensitive conductive network; the cement-based sensing material in Comparative Example 2 lacks porous aggregate, making it difficult to achieve rapid migration and amplification of external moisture into the internal conductive network; and the cement-based sensing material in Comparative Example 3 lacks conductive filler, making it difficult to form a stable and continuous conductive path. This demonstrates that the synergistic design among porous aggregate, sensing functional particles, and conductive filler in this invention is key to achieving lower base resistivity, higher moisture sensitivity, faster response speed, and better cycle stability.

[0052] Furthermore, the cyclic stability coefficient of the cement-based sensing materials in Examples 1-3 remained between 95% and 105% after the 10th dry-wet cycle, and the baseline drift rate was controlled within 15%, indicating that the cement-based sensing materials of the present invention have good response repeatability and long-term monitoring potential under repeated dry-wet conditions.

[0053] In summary, the present invention, through the synergistic design of porous aggregate and sensing functional particles, enables the resulting cement-based sensing material to simultaneously possess significant static resistivity differences, high moisture sensitivity, fast response speed, and good cyclic stability, thereby well meeting the application requirements for seepage risk monitoring of hydraulic structures.

[0054] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A cement-based sensing material, characterized in that, The components include the following parts by weight: Cementitious material: 100 parts; Porous aggregate: 50 parts to 300 parts; Sensing functional particles: 1 to 3 parts; Water-reducing agent: 0.3 to 4 parts; The sensing functional particles are composed of hydrogel polymers and conductive fillers.

2. The cement-based sensing material according to claim 1, characterized in that: The hydrogel polymer in the sensing functional particles is at least one of polyacrylamide, polyacrylic acid, and acrylamide-acrylic acid copolymer; and / or, the conductive filler in the sensing functional particles is at least one of graphite, polypyrrole particles, and carbon black.

3. The cement-based sensing material according to claim 1, characterized in that: The sensing functional particles are prepared by a method including the following steps: mixing monomers, crosslinking agents, initiators, accelerators, conductive fillers and surfactants for polymerization reaction, followed by freeze drying and pulverization to obtain sensing functional particles.

4. The cement-based sensing material according to claim 3, characterized in that: The mass ratio of the monomer to the conductive filler is 1:0.05 to 0.

15.

5. The cement-based sensing material according to claim 3, characterized in that: The polymerization reaction is carried out at a temperature of 40℃ to 70℃ for a reaction time of 0.5h to 3h.

6. The cement-based sensing material according to any one of claims 1 to 5, characterized in that: The cementing material is at least one of ordinary Portland cement, Portland cement, slag Portland cement, and fly ash Portland cement; or, the cementing material is a mixture of at least one of ordinary Portland cement, Portland cement, slag Portland cement, and fly ash Portland cement with at least one of fly ash, granulated blast furnace slag powder, silica fume, and limestone powder.

7. The cement-based sensing material according to any one of claims 1 to 5, characterized in that: The porous aggregate is at least one of porous ceramsite, porous glass particles, and porous mineral particles; and / or the particle size of the porous aggregate is 0.5 mm to 10 mm.

8. A method for preparing a cement-based sensing material as described in any one of claims 1 to 7, characterized in that, Includes the following steps: The cementitious material, porous aggregate, sensing functional particles, water-reducing agent and water are mixed evenly, and then molded and cured to obtain cement-based sensing material.

9. A cement-based sensor, characterized in that, It includes the cement-based sensing material according to any one of claims 1 to 7.

10. An application of a cement-based sensing material as described in any one of claims 1 to 7 for health monitoring of hydraulic structures.

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