Cementitious material for high ductility concrete composite board and preparation method and use thereof

Abstract

This invention discloses a cementitious material for high-ductility concrete composite panels, its preparation method, and its applications. The cementitious material is composed of the following components by weight: 20-30 parts cement, 15-20 parts steel slag powder, 15-20 parts blast furnace slag powder, 15-20 parts fly ash, 5-8 parts silica fume, and 8-15 parts limestone powder or quartz powder. The fineness of the limestone powder or quartz powder is 200-325 mesh. This invention introduces limestone powder or quartz powder as an inert filler sixth component into the traditional five-element solid waste system, utilizing the physical filling effect of inert particles to densify the matrix and achieve decoupling of compressive strength and tensile ductility. When combined with PE fiber and quartz sand aggregate, the compressive strength reaches 45-60 MPa and the ultimate tensile strain is 1.5-2.5% after 28 days of curing at room temperature. This invention has a simple composition, a self-consistent mechanism, is low-carbon and environmentally friendly, and is specifically designed for high-ductility concrete composite panels.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a cementitious material for high-ductility concrete composite panels, its preparation method, and its applications. Background Technology

[0002] High-ductility concrete (ECC) is widely used in structural reinforcement, precast components, and seismic engineering due to its significant tensile strain hardening characteristics and multi-crack features. ECC is typically composed of cement, mineral admixtures, fine aggregates, fibers, and chemical additives, and its ultimate tensile strain can reach more than 3%, far exceeding that of ordinary concrete.

[0003] Composite panels, as a type of prefabricated assembled component, are composed of structural layers and insulation layers, and their demand in prefabricated buildings is increasing. However, existing ECC cementitious materials have the following main shortcomings: First, the cement content is generally high, resulting in high carbon emissions and large drying shrinkage, which easily leads to warping and interface cracking when used in composite panels; second, the expansion agents introduced to reduce shrinkage have problems such as difficulty in matching the hydration sequence and poor synergy with fibers, which can easily lead to uncontrolled cracking or decreased ductility; third, the cementitious material system is mostly based on active components such as cement, fly ash, and slag, with a single composition, making it difficult to achieve a coordinated unity of low carbon and high performance; fourth, existing cementitious materials are mostly general-purpose and lack specific designs for composite panel applications.

[0004] Therefore, developing a low-carbon, low-shrinkage cementitious material that is compatible with ECC and specifically designed for composite panels is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a cementitious material for high-ductility concrete composite panels, its preparation method, and its applications. This invention introduces limestone powder or quartz powder as a sixth element into a five-element system of cement-steel slag-blast furnace slag-fly ash-silica fume. Utilizing a physical filling effect, it achieves decoupling of strength and ductility. Under normal temperature curing, the compressive strength reaches 45-60 MPa, and the ultimate tensile strain reaches 1.5-2.5%. No expansion agent or steam curing is required, making it specifically designed for high-ductility concrete composite panels.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A cementitious material for high-ductility concrete composite panels, the cementitious material being composed of the following raw materials in parts by weight: 20-30 parts cement, 15-20 parts steel slag powder, 15-20 parts blast furnace slag powder, 15-20 parts fly ash, 5-8 parts silica fume, and 8-15 parts limestone powder or quartz powder.

[0007] Optionally, the limestone powder or quartz powder has a fineness of 200-325 mesh.

[0008] Optionally, the free calcium oxide content in the steel slag powder is ≤3%.

[0009] Optionally, the slag powder is grade S95 or higher; the fly ash is grade II or higher.

[0010] Optionally, the cement is P·O 42.5 or P·O 52.5 ordinary Portland cement.

[0011] Optionally, the preparation method of the cementitious material for high-ductility concrete composite panels according to any one of claims 1-5 includes the following specific preparation steps: S1. Weigh the raw materials according to the proportion, place the steel slag powder and slag powder in a drying oven at 105±5℃ and dry them to constant weight, then remove and cool to room temperature; pass all raw materials through a 0.5mm square hole sieve to remove agglomerates and impurities, and set aside for later use. S2. The cement, steel slag powder, slag powder and fly ash treated in S1 are put into a three-dimensional motion mixer and dry-mixed at a speed of 50-100 r / min for 3-5 min to obtain the initial mixture. S3. Add silica fume, limestone powder or quartz powder to the initial mixture of S2, and continue to dry mix at a speed of 80-120 r / min for 3-5 min to make the ultrafine particles evenly fill the gaps between the main materials. S4. Stir the mixture obtained in S3 at a speed of 100-150 r / min for 2-4 min until the color of each component is visually uniform and there is no layering. S5. Place the cementitious material obtained in S4 in a sealed container and age it for 12-24 hours to allow all components to be fully homogenized. Finally, seal and package it according to the predetermined specifications to obtain the cementitious material for high ductility concrete composite panels.

[0012] Optionally, the application of the cementitious material for the high-ductility concrete composite panel includes the following steps: mixing the cementitious material with 70-140 mesh continuously graded quartz sand aggregate, PE fiber, water, and polycarboxylate superplasticizer in the following manner: dry-mix the cementitious material and quartz sand aggregate for 30-60 seconds, add water and superplasticizer and wet-mix for 2-3 minutes, then add PE fiber and stir for 2-3 minutes until evenly dispersed, then pour into a mold, vibrate to compact, and cover and cure at 20-25℃ for 7 days to obtain the high-ductility concrete composite panel.

[0013] Optionally, the PE fiber has a volumetric doping content of 1.5-2.0%, a diameter of 18-22 μm, a length of 12-18 mm, and its surface is plasma-modified or grafted with polar groups.

[0014] Optionally, the water-cement ratio is 0.22-0.25; the water-reducing agent dosage is 0.2-0.3% of the total amount of cementitious materials.

[0015] The beneficial effects of this invention are as follows: Limestone powder or quartz powder is introduced as the sixth element into the five-element solid waste system of cement-steel slag-blast furnace slag-fly ash-silica fume. The matrix is ​​densified using a physical filling effect, achieving decoupling of strength and ductility without the need for expansion agents and shrinkage reducers. Under normal temperature curing, the compressive strength reaches 45-60 MPa, and the ultimate tensile strain reaches 1.5-2.5%. It makes extensive use of industrial solid waste, resulting in low carbon emissions, environmental friendliness, and low cost. The gradient feeding and graded mixing preparation method ensures good homogeneity, eliminates the need for steam curing, and is well-suited to the production rhythm of prefabrication plants. The cementitious material is used in conjunction with PE fiber and quartz sand aggregate, simplifying construction. It is specifically designed for high-ductility concrete composite panels and effectively avoids interface cracking problems. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0017] Example 1: A high-ductility concrete composite slab cementitious material of Example 1, the cementitious material is prepared from the following raw materials in parts by weight: 25 parts cement (P·O 42.5 ordinary Portland cement), 18 parts steel slag powder, 18 parts blast furnace slag powder (S95 grade blast furnace slag powder), 16 parts fly ash (Grade II fly ash), 6 parts silica fume, and 12 parts limestone powder (fineness 250 mesh). This embodiment describes a method for preparing a cementitious material for high-ductility concrete composite panels. The specific preparation steps are as follows: S1. Weigh each raw material according to the proportion. Place the steel slag powder (free calcium oxide content of 2.5%) and slag powder in a drying oven at 105℃ and dry them to constant weight. Take them out and cool them to room temperature. Pass all raw materials through a 0.5mm square hole sieve for later use. S2. The cement, steel slag powder, slag powder and fly ash treated in S1 are put into a three-dimensional motion mixer and dry-mixed at 80 r / min for 4 min to obtain the initial mixture. S3. Add silica fume and limestone powder to the initial mixture of S2, and continue to dry mix for 4 minutes at a speed of 100 r / min. S4. Stir the mixture obtained in S3 at 120 r / min for 3 minutes until the color is visually uniform and there is no layering. S5. Place the gelling material obtained in S4 in a sealed container and age for 18 hours, then seal and package it.

[0018] The method for preparing a high-ductility concrete composite panel includes the following steps: S1. Take the cementitious material obtained from S5 and dry mix it with 70-140 mesh continuously graded quartz sand aggregate (45% by volume) for 45 seconds. S2. Add water and polycarboxylate superplasticizer to the dry mix of S1. The water-to-binder ratio is 0.23, and the superplasticizer dosage is 0.25% of the total amount of cementitious material. Mix wet for 2.5 minutes. S3. Add PE fibers to the slurry of S2 at a volume ratio of 1.8%, with a diameter of 20μm and a length of 15mm. The surface is modified by plasma, and the mixture is stirred for 2.5min until it is evenly dispersed. S4. Pour the S3 mixture into the mold, vibrate to compact it, and cover and cure at 22℃ for 7 days to obtain a high-ductility concrete composite panel.

[0019] Example 2: A high-ductility concrete composite slab cementitious material of Example 2, the cementitious material is prepared from the following raw materials in parts by weight: 20 parts cement (P·O 42.5 ordinary Portland cement), 15 parts steel slag powder, 15 parts blast furnace slag powder (S95 grade blast furnace slag powder), 15 parts fly ash (Grade II fly ash), 5 parts silica fume, and 8 parts limestone powder (fineness 250 mesh). In this embodiment, the cementitious material for a high-ductility concrete composite panel and the preparation method of the high-ductility concrete composite panel are the same as in Example 1.

[0020] Example 3: A high-ductility concrete composite slab cementitious material of Example 3, the cementitious material is prepared from the following raw materials in parts by weight: 30 parts cement (P·O 42.5 ordinary Portland cement), 20 parts steel slag powder, 20 parts blast furnace slag powder (S95 grade blast furnace slag powder), 20 parts fly ash (Grade II fly ash), 8 parts silica fume, and 15 parts limestone powder (fineness 250 mesh). In this embodiment, the cementitious material for a high-ductility concrete composite panel and the preparation method of the high-ductility concrete composite panel are the same as in Example 1.

[0021] Example 4: A high-ductility concrete composite slab cementitious material of Example 4, the cementitious material is prepared from the following raw materials in parts by weight: 25 parts cement (P·O 52.5 ordinary Portland cement), 18 parts steel slag powder, 18 parts blast furnace slag powder (S95 grade blast furnace slag powder), 16 parts fly ash (Grade II fly ash), 6 parts silica fume, and 12 parts quartz powder (fineness 250 mesh). In this embodiment, the cementitious material for a high-ductility concrete composite panel and the preparation method of the high-ductility concrete composite panel are the same as in Example 1.

[0022] Comparative Example 1: The cementitious material of Comparative Example 1 was prepared from the following parts by weight of raw materials: 25 parts cement (P·O 42.5 ordinary Portland cement), 18 parts steel slag powder, 18 parts blast furnace slag powder (S95 grade blast furnace slag powder), 16 parts fly ash (Grade II fly ash), and 6 parts silica fume. In this comparative example, the preparation method of the cementitious material and the high-ductility concrete composite panel is the same as that in Example 1, except that limestone powder is not added.

[0023] Comparative Example 2: The cementitious material of Comparative Example 2 was prepared from the following parts by weight of raw materials: 25 parts cement (P·O 42.5 ordinary Portland cement), 18 parts steel slag powder, 18 parts blast furnace slag powder (S95 grade blast furnace slag powder), 16 parts fly ash (Grade II fly ash), 6 parts silica fume, and 24 parts limestone powder (fineness 250 mesh). In this comparative example, the preparation method of the cementitious material and the high-ductility concrete composite panel is the same as that in Example 1, except that limestone powder is added in excess.

[0024] Performance testing 1. Ultimate tensile strain and tensile strength test This invention, referring to JC / T 2461-2018 "Test Method for Mechanical Properties of High-Ductility Fiber-Reinforced Cement-Based Composite Materials", uses dog-bone specimens for uniaxial tensile testing to determine the ultimate tensile strain and tensile strength. The specific steps are as follows: A mixture of cementitious materials, quartz sand, PE fiber, water, and water-reducing agent is prepared according to the proportions of the examples and comparative examples. This mixture is then poured into a dog-bone specimen mold. The middle parallel section of the dog-bone specimen has a cross-sectional dimension of 30mm × 15mm and a length of 100mm. The cross-sectional dimensions of the clamping sections at both ends are 60mm × 15mm. After molding, the specimens are covered and cured at 22℃ for 28 days. After the curing period, the two ends of the specimen are clamped in a universal test... In the testing fixture, the specimen is ensured to be centered and the loading direction coincides with the long axis of the specimen. A displacement gauge with a range of 5 mm and an accuracy of 0.001 mm is installed at each end of the parallel section of the specimen, with a gauge length of 80 mm. The testing machine applies tensile load in a displacement-controlled manner at a loading rate of 0.15 mm / min and automatically records the load-deformation curve. The ultimate tensile strain and ultimate tensile strength are calculated based on the load-deformation curve, where the ultimate tensile strain is the strain value corresponding to the maximum load, and the ultimate tensile strength is the maximum load divided by the cross-sectional area of ​​the parallel section of the specimen (450 mm2). Three specimens are tested for each mix proportion, and the arithmetic mean is taken as the final result.

[0025] Table 1. Test data of ultimate tensile strain and tensile strength of different samples

[0026] The ultimate tensile strain of each embodiment of the present invention is 1.68-2.35%, and the ultimate tensile strength is 4.21-5.13 MPa. The ultimate tensile strain of Comparative Example 1 is 43% lower than that of Example 1, and that of Comparative Example 2 is 57% lower than that of Example 1. The results show that the physical filling effect of limestone powder or quartz powder can enhance the density of the matrix and the interfacial bonding of the fiber, and improve ductility; the multi-crack mechanism is destroyed when it is not added or is added in excessive amounts.

[0027] 2. 28-day compressive strength test This invention, referring to GB / T 50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete", uses cubic specimens for compressive strength testing. The specific steps are as follows: According to the examples and comparative proportions, cementitious materials, quartz sand, PE fiber, water, and water-reducing agent are mixed to prepare a mixture, which is then poured into a 100mm×100mm×100mm cubic mold. The mixture is vibrated on a vibrating table until the surface is covered with slurry, smoothed, and then cured in a standard curing room at 20±3℃ and relative humidity above 90% for 24 hours before demolding. Curing continues under the same conditions for 28 days. After the curing period, the specimen is removed, wiped clean, and placed upright in the center of the lower pressure plate of the compression testing machine, ensuring that the pressure-bearing surface of the specimen is in contact with the surface formed during molding. With the top surface vertical, start the testing machine. When the upper pressure plate approaches the specimen, adjust the ball seat to ensure even contact. Apply the load continuously and uniformly at a loading rate of 0.5 MPa / s until the specimen fails, and record the failure load. Test 3 specimens for each mix proportion. Calculate the compressive strength of each specimen using the formula f=P / A (f is the compressive strength, P is the failure load, and A is the bearing area of ​​10000 mm2). Take the arithmetic mean as the final result. When the difference between the maximum or minimum value and the median value among the three specimens exceeds 15% of the median value, take the median value as the compressive strength of the specimen in that group. When the difference between the maximum and minimum values ​​and the median value both exceed 15% of the median value, the test results for that group are invalid.

[0028] Table 2. Test data of compressive strength of different samples at 28 days

[0029] The 28-day compressive strength of each embodiment of the present invention is 46.8-58.5 MPa, which meets the design target. Comparative Example 1 shows a 17% decrease compared to Example 1, and Comparative Example 2 shows a 29% decrease compared to Example 1. The results show that an appropriate amount of limestone powder or quartz powder can increase the matrix density and thus improve the strength, while an excessive amount dilutes the active component and leads to a decrease in strength.

[0030] 3. 28-day drying shrinkage test This invention refers to the shrinkage test provisions in GB / T 50082-2009 "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete". A 100mm×100mm×400mm prism specimen is used for drying shrinkage testing. The specific steps are as follows: A mixture of cementitious materials, quartz sand, PE fiber, water, and water-reducing agent is prepared according to the proportions of the examples and comparative examples. This mixture is then poured into a 100mm×100mm×400mm prism mold. Stainless steel probes are pre-embedded at the center positions of both ends of the specimen. The test is then performed on a vibration table. The sample was vibrated until the surface was covered with slurry, then smoothed and cured in a standard curing room at 20±2℃ for 3 days. After curing, the sample was removed and immediately transferred to a constant temperature and humidity room at 20±2℃ and 60±5% relative humidity. The initial length of the sample was measured, and the shrinkage was measured at 1d, 3d, 7d, 14d, and 28d. The length was measured using a length comparator with an accuracy of 0.001mm and a gauge length of 300mm. Three samples were tested for each mix proportion, and the arithmetic mean was taken as the final result.

[0031] Table 3. Test data on drying shrinkage values ​​of different samples (unit: ×10⁻⁶)

[0032] The 28-day drying shrinkage of each embodiment of the present invention was 685-762×10⁻⁶, all controlled within 800×10⁻⁶. Comparative Example 1 showed an increase of 19% compared to Example 1, and Comparative Example 2 showed an increase of 21% compared to Example 3. The results show that limestone powder or quartz powder inhibits shrinkage through physical filling; shrinkage increases significantly when not added, and rebounds when added in excess.

[0033] 4. Initial crack tensile strength test This invention refers to the initial crack tensile strength specified in JC / T 2461-2018 "Test Method for Mechanical Properties of High-Ductility Fiber-Reinforced Cement-Based Composite Materials". It uses the same dog-bone specimen and testing apparatus as the ultimate tensile strain test. The specific steps are as follows: A mixture of cementitious materials, quartz sand, PE fiber, water, and water-reducing agent is prepared according to the proportions of the examples and comparative examples. This mixture is then poured into a dog-bone specimen mold. The middle parallel section of the dog-bone specimen has a cross-sectional dimension of 30mm × 15mm and a length of 100mm. The cross-sectional dimensions of the clamping sections at both ends are 60mm × 15mm. After molding, the specimen is covered and cured at 22℃ for 28 days. After curing, the two ends of the specimen are clamped in the universal testing machine fixture, ensuring the specimen is centered and the loading direction coincides with the long axis of the specimen. A displacement gauge with a range of 5mm and an accuracy of 0.001mm is installed at each end of the parallel section of the specimen, with a gauge length of 80m. m; The testing machine applies tensile load in a displacement-controlled manner at a loading rate of 0.15 mm / min and automatically records the load-deformation curve; During loading, the first stiffness abrupt change inflection point of the load-deformation curve is taken as the initial crack point, which is only observed with a magnifying glass and is not used as a judgment criterion. The stress corresponding to this load is the initial crack tensile strength, which is calculated by the following formula: ftc = Pc / A, where ftc is the initial crack tensile strength (MPa), Pc is the initial crack load (N), and A is the cross-sectional area of ​​the parallel section of the specimen (mm2, taken as 450 mm2); The initial crack strain can also be read simultaneously from the load-deformation curve; When the first crack appears in the specimen during loading, if there is no obvious inflection point in the load-deformation curve, the initial crack point can be determined by combining acoustic emission monitoring or observation with a magnifying glass; Three specimens are tested for each mix proportion, and the arithmetic mean is taken as the final result.

[0034] Table 4. Test data of initial crack tensile strength of different samples

[0035] The initial crack tensile strength of each embodiment of the present invention is 2.86-3.42 MPa. Comparative Example 1 shows a 22% decrease compared to Example 1, and Comparative Example 2 shows a 38% decrease compared to Example 3. The results indicate that an appropriate amount of limestone powder or quartz powder can increase the initial cracking stress of the matrix, which is beneficial for delaying crack initiation.

[0036] 5. Tests on average crack width and average crack spacing This invention refers to the provisions of JC / T 2461-2018 "Test Method for Mechanical Properties of High-Ductility Fiber-Reinforced Cement-Based Composite Materials" regarding the average crack spacing and average crack width. It uses the same dog-bone specimen and testing apparatus as the ultimate tensile strain test. The specific steps are as follows: A mixture of cementitious materials, quartz sand, PE fiber, water, and water-reducing agent is prepared according to the proportions of the examples and comparative examples. This mixture is then poured into a dog-bone specimen mold. The cross-sectional dimensions of the middle parallel section of the dog-bone specimen are 30mm × 15mm, and the length of the parallel section is 100mm. The cross-sectional dimensions of the clamping sections at both ends are 60mm × 15mm. After molding, the specimen is covered and cured at 22℃ for 28 days. After the curing period, the two ends of the specimen are clamped in the universal testing machine fixture, ensuring that the specimen is centered and the loading direction coincides with the long axis of the specimen. A displacement gauge with a range of 5mm and an accuracy of 0.001mm is installed at each end of the parallel section of the specimen. The distance between the cracks is 80 mm. The testing machine applies tensile load in a displacement-controlled manner at a loading rate of 0.15 mm / min and automatically records the load-deformation curve. The test is stopped after the specimen is completely destroyed. All crack parameters are uniformly observed and statistically analyzed within the gauge length of the parallel section. The width and spacing of all cracks appearing on the surface of the parallel section of the specimen are measured using a crack observation instrument with a reading accuracy of 0.01 mm or a magnifying glass with a scale. The average crack width is calculated by the following formula: ωm = Σωi / n, where ωm is the average crack width (mm), ωi is the width of the i-th crack (mm), and n is the total number of cracks. The average crack spacing is calculated by the following formula: lm = L / n, where lm is the average crack spacing (mm), L is the measured length of the parallel section of the specimen (mm), and n is the number of cracks within that length. Three specimens are tested for each mix proportion, and the arithmetic mean is taken as the final result.

[0037] Table 5. Test data on average crack width and average crack spacing for different samples.

[0038] The average crack width in each embodiment of the present invention is 72-98 μm (≤100 μm), and the average crack spacing is 2.8-3.8 mm. In Comparative Example 1, the crack width is increased to 145 μm and the spacing to 5.5 mm; in Comparative Example 2, these are further increased to 168 μm and 6.2 mm. The results show that an appropriate amount of limestone powder or quartz powder is beneficial for ECC to achieve "fine and dense" steady-state multi-crack development; without addition or with excessive addition, the crack morphology deteriorates.

Claims

1. A cementitious material for high-ductility concrete composite panels, characterized in that, The cementitious material is composed of the following raw materials in parts by weight: 20-30 parts cement, 15-20 parts steel slag powder, 15-20 parts blast furnace slag powder, 15-20 parts fly ash, 5-8 parts silica fume, and 8-15 parts limestone powder or quartz powder.

2. The cementitious material for high-ductility concrete composite panels according to claim 1, characterized in that, The fineness of the limestone powder or quartz powder is 200-325 mesh.

3. The cementitious material for high-ductility concrete composite panels according to claim 1, characterized in that, The free calcium oxide content in the steel slag powder is ≤3%.

4. The cementitious material for high-ductility concrete composite panels according to claim 1, characterized in that, The slag powder is grade S95 or higher; the fly ash is grade II or higher.

5. The cementitious material for high-ductility concrete composite panels according to claim 1, characterized in that, The cement is P·O 42.5 or P·O 52.5 ordinary Portland cement.

6. A method for preparing a cementitious material for a high-ductility concrete composite slab according to any one of claims 1-5, characterized in that, The specific preparation steps are as follows: S1. Weigh the raw materials according to the proportion, place the steel slag powder and slag powder in a drying oven at 105±5℃ and dry them to constant weight, then remove and cool to room temperature; pass all raw materials through a 0.5mm square hole sieve to remove agglomerates and impurities, and set aside for later use. S2. The cement, steel slag powder, slag powder and fly ash treated in S1 are put into a three-dimensional motion mixer and dry-mixed at a speed of 50-100 r / min for 3-5 min to obtain the initial mixture. S3. Add silica fume, limestone powder or quartz powder to the initial mixture of S2, and continue to dry mix at a speed of 80-120 r / min for 3-5 min to make the ultrafine particles evenly fill the gaps between the main materials. S4. Stir the mixture obtained in S3 at a speed of 100-150 r / min for 2-4 min until the color of each component is visually uniform and there is no layering. S5. Place the cementitious material obtained in S4 in a sealed container and age it for 12-24 hours to allow all components to be fully homogenized. Finally, seal and package it according to the predetermined specifications to obtain the cementitious material for high ductility concrete composite panels.

7. The use of a cementitious material for high-ductility concrete composite panels according to any one of claims 1-5, characterized in that, The steps are as follows: Mix the cementitious material with 70-140 mesh continuously graded quartz sand aggregate, PE fiber, water and polycarboxylate superplasticizer in the following manner: Dry mix the cementitious material and quartz sand aggregate for 30-60 seconds, add water and superplasticizer and wet mix for 2-3 minutes, then add PE fiber and stir for 2-3 minutes until evenly dispersed, then pour into the mold, vibrate to compact, and cover and cure at 20-25℃ for 7 days to obtain a high ductility concrete composite slab.

8. The use of the cementitious material for high-ductility concrete composite panels according to claim 7, characterized in that, The PE fiber has a volumetric doping content of 1.5-2.0%, a diameter of 18-22 μm, a length of 12-18 mm, and its surface is plasma-modified or grafted with polar groups.

9. The use of the cementitious material for high-ductility concrete composite panels according to claim 7, characterized in that, The water-cement ratio is 0.22-0.25; the water-reducing agent dosage is 0.2-0.3% of the total amount of cementitious materials.

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