A novel adaptive cementitious material for seawater conditioning, its preparation method and application

Abstract

This invention discloses a novel adaptive cementitious material for seawater conditioning, its preparation method, and its application. The cementitious material comprises the following components: 30-70 parts by weight of silicate cement, 20-50 parts by weight of auxiliary cementitious materials, 5-15 parts by weight of high-Belitte calcium sulfoaluminate cement clinker and / or high-Belitte calcium aluminoferrite cement clinker, 6-14 parts by weight of nanoparticle sol, 1-3 parts by weight of water-reducing agent, 3-7 parts by weight of nanoparticle stabilizer, and 28-50 parts by weight of mixing water. The nanoparticle sol includes both nano-silica sol and nano-alumina sol, with the silica sol connecting the two sol particles through the dehydration condensation of Si-OH on its surface and -COOH on the surface of the alumina sol to form -COO-. The cementitious material of this invention exhibits high early strength, steadily increasing later strength, strong chloride ion curing ability, and strong resistance to chloride ion erosion, demonstrating excellent durability and resistance to seawater erosion.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cement-based pavement materials, in particular to a seawater mixing and curing self-adaptive novel cementitious material and a preparation method and application thereof. BACKGROUND

[0002] The information disclosed in this Background section is only for the purpose of increasing an understanding of the general background of the application and does not necessarily constitute an admission or a recognition that the information forms part of the prior art already known to a person of ordinary skill in the art.

[0003] With the rapid development of infrastructure construction in the marine environment, the number and scale of reinforced concrete structures used are large, so that high workability and high durability marine concrete is widely used. However, in the open ocean where fresh water resources are scarce, seawater mixing and curing cement concrete is needed for construction, which puts new requirements on cement concrete. The structural stability of traditional cement concrete deteriorates under the erosion of harmful ions in seawater, and even the late strength decreases. The reasons mainly include:

[0004] (1) A large amount of Ca(OH)2 produced by silicate cement hydration is easily dissolved under long-term immersion and flushing in a multi-ion seawater solution, leading to deterioration of the microstructure of the cement-based material.

[0005] (2) In the seawater mixing and curing cement-based material system, the seawater used for mixing and curing is rich in Cl - , Mg 2+ and SO4 2+ , etc. As the cement hydration reaction in the concrete structure proceeds, the concrete matrix structure gradually becomes dense. The presence of the above ions leads to the production of a large number of expansion phases in the later stage of cement hydration, resulting in expansion and cracking of the concrete matrix and damage to the concrete structure.

[0006] Under seawater mixing and curing conditions, there is currently a lack of a novel cementitious material that can still maintain the continuous increase of strength in the process of marine special environment and multi-ion coupling erosion. SUMMARY

[0007] In view of the problem that the current cement concrete material cannot effectively respond to the coupling effect of multiple harmful factors in seawater, the present application provides a seawater mixing and curing self-adaptive novel cementitious material and a preparation method and application thereof, which can realize the steady increase of strength under seawater mixing and curing conditions and improve the durability of marine concrete structures in seawater. Specifically, the present application discloses the technical scheme as shown below.

[0008] First, this invention provides a novel adaptive cementitious material for seawater conditioning, comprising the following components: 30-70 parts by weight of silicate cement, 20-50 parts by weight of auxiliary cementitious materials, 5-15 parts by weight of high-Belitte calcium sulfoaluminate cement clinker and / or high-Belitte calcium aluminoferrite cement clinker, 6-14 parts by weight of silica-alumina sol composite (DSA), 1-3 parts by weight of water-reducing agent, 3-7 parts by weight of nanoparticle stabilizer, and 28-50 parts by weight of mixing water. The silica-alumina sol composite (DSA) simultaneously comprises nano-silica sol and nano-alumina sol, and the silica sol connects the two sol particles through the dehydration condensation of Si-OH on its surface and -COOH on the surface of the alumina sol to form -COO-, thereby forming the DSA.

[0009] Furthermore, the auxiliary cementitious material includes at least one of slag powder, fly ash, and silica fume. Optionally, the fineness of the auxiliary cementitious material is 200-400 mesh.

[0010] Further, the mass ratio of the nano-silica sol to the nano-aluminum sol is 0.5–1.5:0.5–1.5. Optionally, the particle size of both the nano-silica sol and the nano-aluminum sol is 10–20 nm. The solid content of both the nano-silica sol and the nano-aluminum sol is 20–50%.

[0011] Furthermore, the water-reducing agent includes at least one of polycarboxylate water-reducing agents, naphthalene-based water-reducing agents, and lignin sulfonate water-reducing agents.

[0012] Furthermore, the nanoparticle stabilizer includes at least one of: cocamidopropyl betaine, cocamidopropyl hydroxysulfonate ammonium, alkyl acyl imidazoline, etc. This invention utilizes the characteristic that the nanoparticle stabilizer contains both hydrophilic and hydrophobic groups. One end of its hydrophilic group rapidly complexes with the hydrophilic groups on the surface of the silica-alumina sol-gel (DSA) composite, while the hydrophobic group is exposed on the surface of the DSA, thereby forming an electrical double layer and a steric hindrance layer. This generates electrostatic repulsion and steric hindrance effects, preventing the DSA particles from agglomerating and maintaining the DSA in a stable and uniformly dispersed state.

[0013] Furthermore, the mixing water includes at least one of fresh water, seawater, etc.

[0014] Secondly, this invention provides a method for preparing the aforementioned seawater conditioning adaptive novel cementitious material, comprising the following steps:

[0015] (1) Mix the silicate cement, auxiliary cementitious materials, high belite calcium sulfoaluminate cement clinker and / or high belite calcium ferroaluminate cement clinker to obtain a mixed powder for later use.

[0016] (2) The nano-silica sol and nano-alumina sol are mixed and ultrasonically treated to obtain a silica-alumina sol composite (DSA). The silica sol is formed by the dehydration condensation of Si-OH on its surface and -COOH on the surface of the aluminum sol to form -COO-, which connects the two sol particles.

[0017] (3) The nanoparticle stabilizer is added to the silica-alumina sol composite and mixed to obtain the modified silica-alumina sol composite. Then the composite is added to the mixing water and mixed. The mixed powder and water-reducing agent are then added and mixed to obtain the gelling material.

[0018] Furthermore, in step (2), the ultrasonic treatment time is 30 to 90 minutes and the ultrasonic power is 60 to 100 W.

[0019] Finally, this invention provides the application of the novel seawater conditioning adaptive cementitious material in marine engineering, water conservancy engineering, hydropower engineering, bridge engineering and other fields.

[0020] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0021] The adaptive novel cementitious material for seawater curing of this invention has the advantages of high early strength, steady improvement in later strength, and strong chloride ion solidification, effectively improving the durability of marine concrete structures in seawater. This is because the auxiliary cementitious material has the characteristic of secondary hydration reaction, but this hydration reaction starts relatively late, thus it can begin to play a role in the later stage of cement hydration. It reacts with calcium hydroxide produced by cement hydration to form cementitious components such as calcium silicate hydrate (CSH), thereby reducing the calcium hydroxide content in the concrete structure and converting it into cementitious components with cementitious properties that help improve the mechanical properties of the concrete structure. This reduces the problem of calcium hydroxide corrosion caused by seawater soaking and scouring, which leads to concrete structure damage, strength reduction, and shortened service life. The high activity of the nanoparticle sol can play a role in the early stage of cement hydration, consuming the calcium hydroxide produced by hydration and improving early strength. Among them, the active silicon component in the silica-alumina composite sol (DSA) reacts with calcium hydroxide produced by cement hydration and magnesium ions in seawater to form high-density and high-toughness CSH gel and MSH gel components. The active aluminum component reacts with sulfate ions in seawater and calcium hydroxide, a cement hydration product, to form a high-strength hydrated product called ettringite (AFt). Meanwhile, the active silicon component in DSA participates in cement hydration to generate a low-calcium silicate-to-CSH gel with a longer chain length, effectively resisting the cracking stress caused by matrix expansion during the later stages of cement hydration in seawater-mixed cement. Furthermore, since DSA is a silica-alumina composite, while generating high-toughness CSH and MSH gels, high-strength AFt is also generated based on the same sol particles. These three components grow synchronously in situ, forming a "rigid-flexible" ultra-strong and tough three-dimensional cross-network structure that can encapsulate and entangle chloride ions in seawater, effectively solidifying them. During the hydration reaction, the high-belite calcium sulfoaluminate cement clinker and / or high-belite calcium ferroaluminate cement clinker can solidify free sulfate ions in seawater into trisulfite (AFt) and monosulfite (AFm). The AFm can continue to react with chloride ions in seawater to form Friedel salts, which not only further solidifies the chloride ions but also, because the Friedel salts form in the early stages of concrete hydration, avoids the structural damage caused by later Friedel salt formation. This is because the formation of Friedel salts is an expansion process, but as the cement hydration reaction progresses, the cement matrix gradually becomes denser and its plasticity decreases, making it prone to expansion and cracking due to Friedel salt formation. Furthermore, the high content of high-Belitton phase in the cement clinker concentrates its hydration reaction in the later stages, effectively improving the later-stage strength of the concrete structure.

[0022] It can be seen that the synergistic interaction of the above components effectively eliminates the internal factors of harmful ion damage to the matrix during seawater mixing and the external factors of harmful ion erosion during seawater curing, achieving "dual protection" against both internal and external factors. This overcomes the problem of concrete's inability to effectively cope with the erosion caused by the coupled effects of multiple harmful factors in seawater, solves the problem of freshwater scarcity during ocean-going construction, and is conducive to the implementation of my country's ocean-going construction strategy. The test results of this embodiment show that the prepared seawater-cured adaptive novel cementitious material has excellent durability, resistance to ion erosion, and mechanical strength. Attached Figure Description

[0023] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0024] Figure 1 The image shows a sample of the silica-alumina sol-colloid composite prepared in Example 1 below.

[0025] Figure 2 The image shows the compressive strength test results of the specimen prepared in Example 1 below.

[0026] Figure 3 The XRD pattern of the specimen prepared in Example 1 below.

[0027] Figure 4 SEM images of the specimens prepared in Example 1 below. Detailed Implementation

[0028] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer.

[0029] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as those skilled in the art. The reagents or raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they are used in accordance with conventional methods or product instructions. Furthermore, any methods and materials similar to or equivalent to those described herein can be applied to the methods of this invention. The technical solution of this invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0030] The composition of each kg of simulated seawater in the following examples is shown in Table 1 below:

[0031] Table 1

[0032] NaCl CaCl2 KCl MgCl2 MgSO4 Deionized water 28.208g 1.253g 0.722g 1.101g 3.312g 965.404g

[0033] Example 1

[0034] The preparation of a novel adaptive cementitious material for seawater conditioning includes the following steps:

[0035] (1) The following raw material components are used: 50 parts by weight of 42.5 ordinary Portland cement, 30 parts by weight of auxiliary cementitious material, 10 parts by weight of high-belite calcium sulfoaluminate cement clinker, 10 parts by weight of silica-alumina sol composite, 1 part by weight of polycarboxylate superplasticizer, 5 parts by weight of nanoparticle stabilizer, and 40 parts by weight of simulated seawater as shown in Table 1 above. Wherein: the fineness of the cement (residue on a 200-mesh sieve) is 1.3%, the auxiliary cementitious material is slag powder with a fineness of 200 mesh, and the nanoparticle stabilizer is cocamidopropyl betaine.

[0036] (2) Mix the silicate cement, auxiliary cementitious materials and high belite calcium sulfoaluminate cement clinker and stir for 5 minutes to obtain mixed powder for later use.

[0037] (3) After mixing nano-silica sol and nano-alumina sol at a mass ratio of 1:1, ultrasonic treatment was performed for 60 min at an ultrasonic power of 80 W. The resulting silica-alumina sol composite (e.g.) was then obtained. Figure 1 (As shown). The particle size of both the nano-silica sol and the nano-aluminum sol is distributed between 10 and 20 nm, and the solid content of both is 45%.

[0038] (4) The nanoparticle stabilizer is added to the silica-alumina sol composite and stirred evenly to obtain the modified silica-alumina sol composite. Then the composite is added to the simulated seawater and stirred evenly. The mixed powder and water-reducing agent are then added and stirred evenly to obtain the gelling material.

[0039] Performance testing: (1) The cementitious material prepared in this embodiment was prepared by mixing with simulated seawater according to the standard mortar preparation method of "Test Method for Strength of Cement Mortar (ISO Method)" (GBT 17671-2021). The mortar was poured into a mold, hardened and demolded, and then cured by full immersion in seawater at room temperature. The compressive strength of the specimens at 1d, 28d and 100d were tested respectively. Then the compressive strength retention rate and chloride ion migration coefficient at 28d were tested. Wherein: The compressive strength was tested according to "Test Method for Strength of Cement Mortar (ISO Method)" (GBT 17671-2021) (e.g. Figure 2(As shown), the compressive strength retention rate was calculated according to the "Test Method for Seawater Erosion Resistance of Cement" (GB / T38140-2019), and the chloride ion migration coefficient was tested according to the "Standard for Test Methods of Long-Term Performance and Durability of Ordinary Concrete" (GB / T 50082-2009). (2) The water-soluble chloride ion content of the cementitious material prepared in this embodiment after 28 days of hardening was determined according to the "Technical Specification for Testing Chloride Ion Content in Concrete" (JGJ / T 322-2013), and its percentage of the mass of the cementitious material was calculated. The test results of the above performance indicators are shown in Table 2 below.

[0040] It can be seen that the novel seawater-adaptive cementitious material prepared in this embodiment has the characteristics of high early strength, steady improvement in later strength, strong chloride ion curing ability, and strong resistance to chloride and sulfate ion erosion, exhibiting excellent durability and resistance to seawater erosion.

[0041] Table 2

[0042]

[0043] Figure 3 The XRD patterns of the specimens prepared for this embodiment at curing ages of 1 day, 28 days, and 100 days are shown. It can be seen that at 1 day, Friedel salt peaks from AFm-cured chloride ions begin to appear in the specimens. With increasing curing age, Friedel salt formation becomes significant. The amounts of Friedel salt and AFt formed at 28 days and 100 days remain almost unchanged, indicating that chloride ions were completely cured at 28 days, preventing matrix expansion and cracking caused by later Friedel salt formation and ensuring stable strength improvement.

[0044] Figure 4 The image shows a SEM image of the specimen prepared in this embodiment at 28 days of age. The hydration products circled in different colors correspond to the labels on both sides of the image. It can be seen that Friedel salt, Aft, and CSH gel are present in the specimen, as well as AFm remaining after the absorption of chloride ions and conversion to Friedel salt.

[0045] Example 2

[0046] The preparation of a novel adaptive cementitious material for seawater conditioning includes the following steps:

[0047] (1) Take the following raw material components: 70 parts by weight of 42.5 ordinary silicate cement, 50 parts by weight of auxiliary cementitious material, 10 parts by weight of high belite calcium sulfoaluminate cement clinker, 5 parts by weight of high belite calcium aluminoferrite cement clinker, 14 parts by weight of silica-alumina sol composite, 3 parts by weight of polycarboxylate superplasticizer, 7 parts by weight of nanoparticle stabilizer, and 50 parts by weight of simulated seawater as shown in Table 1 above. Wherein: the fineness of the cement (200 mesh sieve residue) is 1.3%, the auxiliary cementitious material is fly ash with a fineness of 400 mesh, and the nanoparticle stabilizer is cocamidopropyl hydroxysulfonate ammonium.

[0048] (2) Mix the silicate cement, auxiliary cementitious materials and high belite calcium sulfoaluminate cement clinker and stir for 5 minutes to obtain mixed powder for later use.

[0049] (3) The nano-silica sol and nano-alumina sol were mixed at a mass ratio of 0.5:1.5 and then ultrasonically treated for 30 min at an ultrasonic power of 100 W to obtain a silica-alumina sol composite. The particle size of both the nano-silica sol and nano-alumina sol was between 10 and 20 nm, and the solid content of both nano-silica sol and nano-alumina sol was 20%.

[0050] (4) The nanoparticle stabilizer is added to the silica-alumina sol composite and stirred evenly to obtain the modified silica-alumina sol composite. Then the composite is added to the simulated seawater and stirred evenly. The mixed powder and water-reducing agent are then added and stirred evenly to obtain the gelling material.

[0051] Performance testing: The compressive strength of specimens prepared in this embodiment at 1d, 28d, and 100d of age, the compressive strength retention rate of specimens aged 28d after immersion in seawater for 100 days, the chloride ion migration coefficient, and the water-soluble chloride ion content of the cementitious material after hardening were tested using the same method as in Example 1 above, and the percentage of chloride ions by mass of the cementitious material was calculated. The test results of the above performance indicators are shown in Table 3 below.

[0052] It can be seen that the novel seawater-adaptive cementitious material prepared in this embodiment has the characteristics of high early strength, steady improvement in later strength, strong chloride ion curing ability, and strong resistance to chloride and sulfate ion erosion, exhibiting excellent durability and resistance to seawater erosion.

[0053] Table 3

[0054]

[0055] Example 3

[0056] The preparation of a novel adaptive cementitious material for seawater conditioning includes the following steps:

[0057] (1) Take the following raw material components: 30 parts by weight of 42.5 ordinary Portland cement, 20 parts by weight of auxiliary cementitious material, 5 parts by weight of high belite calcium aluminoferrite cement clinker, 6 parts by weight of silica-alumina sol composite, 2 parts by weight of sodium lignosulfonate water-reducing agent, 3 parts by weight of nanoparticle stabilizer, and 28 parts by weight of simulated seawater as shown in Table 1 above. Wherein: the fineness of the cement (200 mesh sieve residue) is 1.3%, the auxiliary cementitious material is silica fume, and the nanoparticle stabilizer is alkyl acyl imidazoline.

[0058] (2) Mix the silicate cement, auxiliary cementitious materials and high belite calcium sulfoaluminate cement clinker and stir for 5 minutes to obtain mixed powder for later use.

[0059] (3) The nano-silica sol and nano-alumina sol were mixed at a mass ratio of 1.5:0.5 and then ultrasonically treated for 90 min at an ultrasonic power of 60 W to obtain a silica-alumina sol composite. The particle size of both the nano-silica sol and nano-alumina sol was distributed between 10 and 20 nm, and the solid content of both nano-silica sol and nano-alumina sol was 50%.

[0060] (4) The nanoparticle stabilizer is added to the silica-alumina sol composite and stirred evenly to obtain the modified silica-alumina sol composite. Then the composite is added to the simulated seawater and stirred evenly. The mixed powder and water-reducing agent are then added and stirred evenly to obtain the gelling material.

[0061] Performance testing: The compressive strength of specimens prepared in this embodiment at 1d, 28d, and 100d of age, the compressive strength retention rate of specimens aged 28d after immersion in seawater for 100 days, the chloride ion migration coefficient, and the water-soluble chloride ion content of the cementitious material after hardening were tested using the same method as in Example 1 above, and the percentage of chloride ions by mass of the cementitious material was calculated. The test results of the above performance indicators are shown in Table 4 below.

[0062] It can be seen that the novel seawater-adaptive cementitious material prepared in this embodiment has the characteristics of high early strength, steady improvement in later strength, strong chloride ion curing ability, and strong resistance to chloride and sulfate ion erosion, exhibiting excellent durability and resistance to seawater erosion.

[0063] Table 4

[0064]

[0065] Example 4

[0066] The preparation of a novel adaptive cementitious material for seawater conditioning includes the following steps:

[0067] (1) The following raw material components are used: 50 parts by weight of 42.5 ordinary silicate cement, 30 parts by weight of auxiliary cementitious material, 10 parts by weight of high-belite calcium sulfoaluminate cement clinker, 1 part by weight of polycarboxylate superplasticizer, 5 parts by weight of nanoparticle stabilizer, and 40 parts by weight of simulated seawater as shown in Table 1 above. Wherein: the fineness of the cement (residue on a 200-mesh sieve) is 1.3%, the auxiliary cementitious material is slag powder with a fineness of 200 mesh, and the nanoparticle stabilizer is cocamidopropyl betaine.

[0068] (2) Mix the silicate cement, auxiliary cementitious materials and high belite calcium sulfoaluminate cement clinker and stir for 5 minutes to obtain mixed powder for later use.

[0069] (3) Add the nanoparticle stabilizer to the simulated seawater and stir evenly, then add the mixed powder and water-reducing agent and stir evenly to obtain the gelling material.

[0070] Performance testing: The compressive strength of specimens prepared in this embodiment at 1d, 28d, and 100d of age, the compressive strength retention rate of specimens aged 28d after immersion in seawater for 100 days, the chloride ion migration coefficient, and the water-soluble chloride ion content of the cementitious material after hardening were tested using the same method as in Example 1 above, and the percentage of chloride ions by mass of the cementitious material was calculated. The test results of the above performance indicators are shown in Table 5 below.

[0071] Table 5

[0072]

[0073] Example 5

[0074] The preparation of a novel adaptive cementitious material for seawater conditioning includes the following steps:

[0075] (1) Take the following raw material components: 70 parts by weight of 42.5 ordinary silicate cement, 10 parts by weight of high belite calcium sulfoaluminate cement clinker, 5 parts by weight of high belite calcium aluminoferrite cement clinker, 14 parts by weight of silica-alumina sol composite, 3 parts by weight of polycarboxylate superplasticizer, 7 parts by weight of nanoparticle stabilizer, and 50 parts by weight of simulated seawater as shown in Table 1 above. Wherein: the fineness of the cement (200 mesh sieve residue) is 1.3%, the auxiliary cementitious material is fly ash with a fineness of 400 mesh, and the nanoparticle stabilizer is cocamidopropyl hydroxysulfonate ammonium.

[0076] (2) Mix the silicate cement and high belite calcium aluminate cement clinker and stir for 5 minutes to obtain mixed powder for later use.

[0077] (3) The nano-silica sol and nano-alumina sol were mixed at a mass ratio of 0.5:1.5 and then ultrasonically treated for 30 min at an ultrasonic power of 100 W to obtain a silica-alumina sol composite. The particle size of both the nano-silica sol and nano-alumina sol was between 10 and 20 nm, and the solid content of both nano-silica sol and nano-alumina sol was 20%.

[0078] (4) The nanoparticle stabilizer is added to the silica-alumina sol composite and stirred evenly to obtain the modified silica-alumina sol composite. Then the composite is added to the simulated seawater and stirred evenly. The mixed powder and water-reducing agent are then added and stirred evenly to obtain the gelling material.

[0079] Performance testing: The compressive strength of specimens prepared in this embodiment at 1d, 28d, and 100d of age, the compressive strength retention rate of specimens aged 28d after immersion in seawater for 100 days, the chloride ion migration coefficient, and the water-soluble chloride ion content of the cementitious material after hardening were tested using the same method as in Example 1 above, and the percentage of chloride ions by mass of the cementitious material was calculated. The test results of the above performance indicators are shown in Table 6 below.

[0080] Table 6

[0081]

[0082] Example 6

[0083] The preparation of a novel adaptive cementitious material for seawater conditioning includes the following steps:

[0084] (1) Take the following raw material components: 30 parts by weight of 42.5 ordinary Portland cement, 20 parts by weight of auxiliary cementitious material, 6 parts by weight of silica-alumina sol composite, 2 parts by weight of sodium lignosulfonate water-reducing agent, 3 parts by weight of nanoparticle stabilizer, and 28 parts by weight of simulated seawater as shown in Table 1 above. Wherein: the fineness of the cement (200 mesh sieve residue) is 1.3%, the auxiliary cementitious material is silica fume, and the nanoparticle stabilizer is alkyl acyl imidazoline.

[0085] (2) Mix the silicate cement and auxiliary cementitious materials and stir for 5 minutes to obtain a mixed powder for later use.

[0086] (3) The nano-silica sol and nano-alumina sol were mixed at a mass ratio of 1.5:0.5 and then ultrasonically treated for 90 min at an ultrasonic power of 60 W to obtain a silica-alumina sol composite. The particle size of both the nano-silica sol and nano-alumina sol was distributed between 10 and 20 nm, and the solid content of both nano-silica sol and nano-alumina sol was 50%.

[0087] (4) The nanoparticle stabilizer is added to the silica-alumina sol composite and stirred evenly to obtain the modified silica-alumina sol composite. Then the composite is added to the simulated seawater and stirred evenly. The mixed powder and water-reducing agent are then added and stirred evenly to obtain the gelling material.

[0088] Performance testing: The compressive strength of specimens prepared in this embodiment at 1d, 28d, and 100d of age, the compressive strength retention rate of specimens aged 28d after immersion in seawater for 100 days, the chloride ion migration coefficient, and the water-soluble chloride ion content of the cementitious material after hardening were tested using the same method as in Example 1 above, and the percentage of chloride ions by mass of the cementitious material was calculated. The test results of the above performance indicators are shown in Table 7 below.

[0089] Table 7

[0090]

[0091] Example 7

[0092] The preparation of a novel adaptive cementitious material for seawater conditioning includes the following steps:

[0093] (1) Take the following raw material components: 70 parts by weight of 42.5 ordinary Portland cement, 50 parts by weight of auxiliary cementitious material, 10 parts by weight of high-belite calcium sulfoaluminate cement clinker, 5 parts by weight of high-belite calcium ferroaluminate cement clinker, 14 parts by weight of silica-alumina sol composite, 3 parts by weight of polycarboxylate superplasticizer, and 50 parts by weight of simulated seawater as shown in Table 1 above. Wherein: the fineness of the cement (200 mesh sieve residue) is 1.3%, and the auxiliary cementitious material is fly ash with a fineness of 400 mesh.

[0094] (2) Mix the silicate cement, auxiliary cementitious materials and high belite calcium sulfoaluminate cement clinker and stir for 5 minutes to obtain mixed powder for later use.

[0095] (3) The nano-silica sol and nano-alumina sol were mixed at a mass ratio of 0.5:1.5 and then ultrasonically treated for 30 min at an ultrasonic power of 100 W to obtain a silica-alumina sol composite. The particle size of both the nano-silica sol and nano-alumina sol was between 10 and 20 nm, and the solid content of both nano-silica sol and nano-alumina sol was 20%.

[0096] (4) Add the silicon-aluminum sol composite to the simulated seawater and stir until uniform. Then add the mixed powder and water-reducing agent and stir until uniform to obtain the gelling material.

[0097] Performance testing: The compressive strength of specimens prepared in this embodiment at 1d, 28d, and 100d of age, the compressive strength retention rate of specimens aged 28d after immersion in seawater for 100 days, the chloride ion migration coefficient, and the water-soluble chloride ion content of the cementitious material after hardening were tested using the same method as in Example 1 above, and the percentage of chloride ion content to the mass of the cementitious material was calculated. The test results of the above performance indicators are shown in Table 8 below.

[0098] Table 8

[0099]

[0100] Example 8

[0101] The preparation of a novel adaptive cementitious material for seawater conditioning includes the following steps:

[0102] (1) The following raw material components are used: 50 parts by weight of 42.5 ordinary Portland cement, 30 parts by weight of auxiliary cementitious material, 10 parts by weight of high-belite calcium sulfoaluminate cement clinker, 10 parts by weight of nano-silica sol, 1 part by weight of polycarboxylate superplasticizer, 5 parts by weight of nanoparticle stabilizer, and 40 parts by weight of simulated seawater as shown in Table 1 above. Wherein: the fineness (residue on a 200-mesh sieve) of the cement is 1.3%, and the auxiliary cementitious material is slag powder with a fineness of 200 mesh. The nanoparticle stabilizer is cocamidopropyl betaine. The particle size distribution of the nano-silica sol is between 10 and 20 nm, and the solid content of the nano-silica sol is 45%.

[0103] (2) Mix the silicate cement, auxiliary cementitious materials and high belite calcium sulfoaluminate cement clinker and stir for 5 minutes to obtain mixed powder for later use.

[0104] (3) The nanoparticle stabilizer is added to the nano silica sol and stirred evenly to obtain modified silica sol. Then the modified silica sol is added to the simulated seawater and stirred evenly. The mixed powder and water-reducing agent are then added and stirred evenly to obtain the gelling material.

[0105] Performance testing: The compressive strength of specimens prepared in this embodiment at 1d, 28d, and 100d of age, the compressive strength retention rate of specimens aged 28d after immersion in seawater for 100 days, the chloride ion migration coefficient, and the water-soluble chloride ion content of the cementitious material after hardening were tested using the same method as in Example 1 above, and the percentage of chloride ions by mass of the cementitious material was calculated. The test results of the above performance indicators are shown in Table 9 below.

[0106] Table 9

[0107]

[0108] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail 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 the present invention should be included within the protection scope of the present invention.

Claims

1. A seawater-blended self-adapting novel cementitious material, characterized in that, The cementitious material comprises the following components: Portland cement 30-70 parts by weight, auxiliary cementitious material 20-50 parts by weight, high belite calcium sulphoaluminate cement clinker and / or high belite calcium ferrite cement clinker 5-15 parts by weight, silica-alumina sol complex 6-14 parts by weight, water reducing agent 1-3 parts by weight, nanoparticle stabilizer 3-7 parts by weight, and mixing water 28-50 parts by weight; the silica-alumina sol complex comprises both nanosilica sol and nanoalumina sol, and the nanosilica sol and the nanoalumina sol are connected by dehydration condensation of Si-OH on the surface of the nanosilica sol and -COOH on the surface of the nanoalumina sol to form -COO-; the nanoparticle stabilizer comprises at least one of cocamidopropyl betaine, cocamidopropyl hydroxylsulfonium ammonium, and alkyl acyl imidazoline; and the mixing water is sea water.

2. The seawater-slurry self-adapting novel cementitious material according to claim 1, characterized in that, The auxiliary cementitious material comprises at least one of slag powder, fly ash, and ultrafine powder.

3. The seawater-slurry self-adapting novel cementitious material according to claim 1, characterized in that, The auxiliary cementitious material has a fineness of 200-400 mesh.

4. The seawater-slurry self-adapting novel cementitious material according to claim 1, characterized in that, The mass ratio of the nanosilica sol to the nanoalumina sol is 0.5-1.5:0.5-1.

5.

5. The seawater-slurry self-adapting novel cementitious material according to claim 1, characterized in that, The nanosilica sol has a particle size of 10-20 nm.

6. The seawater-slurry self-adapting novel cementitious material according to claim 1, characterized in that, The nanosilica sol and the nanoalumina sol each have a solid content of 20-50%.

7. The seawater-slurry self-adapting novel cementitious material according to any one of claims 1-6, characterized in that, The water reducing agent comprises at least one of polycarboxylic acid water reducing agent, naphthalene series water reducing agent, and lignin sulfonate water reducing agent.

8. The method for preparing a seawater-slurry self-adapting novel cementitious material according to any one of claims 1-7, characterized in that, The method comprises the following steps: (1) uniformly mixing the Portland cement, the auxiliary cementitious material, the high belite calcium sulphoaluminate cement clinker and / or the high belite calcium ferrite cement clinker to obtain a mixed powder for standby use; (2) mixing the nanosilica sol and the nanoalumina sol and then ultrasonically treating the mixture to obtain a silica-alumina sol complex, wherein the nanosilica sol and the nanoalumina sol are connected by dehydration condensation of Si-OH on the surface of the nanosilica sol and -COOH on the surface of the nanoalumina sol to form -COO-; (3) adding the nanoparticle stabilizer to the silica-alumina sol complex, uniformly mixing the mixture to obtain a modified silica-alumina sol complex, then adding the complex to the mixing water, uniformly mixing the mixture, adding the mixed powder and the water reducing agent, and uniformly mixing the mixture to obtain the cementitious material.

9. The method for preparing seawater-slurry-adaptive novel cementitious material according to claim 8, characterized in that, In step (2), the ultrasonic treatment is performed for 30-90 min at an ultrasonic power of 60-100 W.

10. The sea water mixing self-adaptive new cementitious material according to any one of claims 1-7 or prepared by the method according to any one of claims 8-9, used in marine engineering, water conservancy engineering, water and electricity engineering, or bridge engineering.

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