Fiber reinforced eco-concrete and method of manufacture

Abstract

The present application relates to a kind of technology for inducing marine sessile organism attachment, especially a kind of fiber reinforced ecological concrete and preparation method, belong to the cross field of marine sessile organism and marine concrete.Its material components include: cementitious material, broken stone, sand, water, dark pigment, biological calcium powder, calcium carbonate powder, trace element, chopped fiber and superplasticizer.The purpose of the present application is to induce sessile organism attachment, mainly oyster, in the tidal zone reinforced concrete corrosion prevention, considering the attachment of barnacle.By controlling to use dilute acid modification and composite grinding technology, the inducing capacity of bovine bone powder is fully exerted, the bovine bone powder content is greatly reduced, and corrosion prevention treatment and modification are carried out, a composite inducer mainly composed of bovine bone powder is realized, the content is small, and the concrete strength and permeability are almost not affected.

Description

TECHNICAL FIELD

[0001] The present application relates to a technology for inducing the attachment of marine sessile organisms, in particular to a fiber-reinforced ecological concrete and a preparation method, belonging to the cross field of marine sessile organisms and marine concrete. BACKGROUND

[0002] Reinforced concrete is widely used in marine infrastructure construction, such as seaport wharf, cross-sea bridge, offshore platform and submarine tunnel, etc. However, the problem of steel bar corrosion caused by chloride ion erosion greatly shortens the service life of reinforced concrete structures, bringing huge economic burden to the society. So far, the representative anti-corrosion technologies for reinforced concrete engineering in marine environment mainly include high-performance concrete, surface coating, FRP bar, steel bar corrosion inhibitor and electrochemical protection technology, etc. These anti-corrosion technologies all have some shortcomings or deficiencies, such as one or more of the following: great construction difficulty, material aging and durability deficiency, long-term unpredictability, high cost, etc. In addition, most of the current anti-corrosion technologies are for splash zone, and there are few measures for the anti-corrosion of tidal zone, which has the problems of high cost and poor anti-corrosion effect.

[0003] The surface of concrete engineering in tidal zone is often covered with a large amount of sessile organisms, such as oysters, barnacles, etc. Studies have shown that the biological glue secreted by oysters and barnacles can block the capillary pores on the surface of concrete, hinder the entry and exit of ions and gases, improve the impermeability of concrete, and thus improve its durability, and the denser the attachment of sessile organisms, the more obvious the protection effect. Using marine sessile organisms for corrosion prevention not only has the characteristics of initiative, economy and environmental protection, but also makes up for the limitations of current reinforced concrete corrosion prevention technologies in tidal zone and underwater area. This is the cross of marine concrete and marine sessile organism disciplines, which opens up a new research field of reinforced concrete structure corrosion prevention. However, in some sea areas, sessile organisms are often affected by the external environment, and often appear sparse, loose or even no attachment. Therefore, inducing sessile organisms to attach quickly and densely on the surface of concrete is the key to realizing the corrosion prevention of sessile organisms.

[0004] Meanwhile, due to the rapid development of coastal economy in recent decades and the lack of environmental protection, the large-scale destruction of the coastal ecology has occurred and has had a huge impact on the economy and ecology of China's coast. With the introduction of a series of relevant policies, China's marine engineering construction will also usher in a peak period, and the large-scale construction of marine engineering and the breakwater to protect the surrounding sea area further destroys the fragile marine ecosystem. If appropriate ecological and environmental protection is not taken, it will bring greater disaster to the coastal ecology. At the same time, most of the coastal infrastructure cannot be removed, and the ecology of the sea area needs to be repaired, so people gradually realize that the application of ecological technology on a large number of infrastructure can effectively improve or repair the ecology of the sea area. Therefore, it is very important and urgent to build a concrete project with good ecological effect or to make the existing concrete project ecological to improve the nearshore ecological environment. However, as of now, the ecological technology of breakwater and other projects located in the tidal zone is still in a blank state in China.

[0005] Oysters are "ecological engineers", and they are mainly concentrated in the tidal zone and within 30 meters underwater, and oysters like to attach to shells of the same kind to form thick oyster reefs, so that oysters can be densely attached to breakwaters to achieve the ecologicalization of breakwaters. In addition, the oyster reef is now severely damaged, and most of it needs to be repaired by large-scale oyster attachment to achieve ecological restoration. Therefore, the construction of marine ecological engineering and the repair of oyster reefs can achieve their ecological functions through the large-scale propagation of oysters. Therefore, how to make oysters quickly and densely attach to these projects, metamorphose and grow quickly is crucial. The current domestic and foreign researches are as follows:

[0006] I. Effect of ions on the attachment and metamorphosis of marine sessile organism larvae

[0007] The research on the attachment and metamorphosis of marine sessile organism larvae at home and abroad mainly focuses on the effect of ion concentration in the solution on it. The in-depth research ions and substances include K + , NH3, Ca 2+ and Cu 2+ . The first three ions or substances can promote the attachment or metamorphosis of oysters at an appropriate concentration, but Cu 2+ has no obvious promoting effect, and even a high concentration can increase the mortality of larvae. K + induces larval metamorphosis by affecting the behavior of the cell membrane; NH3 enters the cell, causing the pH value in the cell to rise, and then causing the neurons of the behavior pathway to depolarize, thereby inducing sessile metamorphosis. Although there are many studies on the attachment and metamorphosis of sessile organisms on different materials such as polyethylene plates, shells, and tiles in the solution, such methods are not easy to implement or too costly when applied to actual marine concrete engineering.

[0008] Nowadays, with the extensive application of concrete in marine engineering, especially in recent oyster reef restoration projects, concrete has become a most commonly used substrate for marine sessile organisms. However, concrete is quite different from traditional substrates such as shell, limestone, rubber tire and plastic sheet. Concrete has high alkalinity and high calcium ion, and also contains other ions such as potassium and sodium, which have great influence on the settlement and growth of oysters. Although some oyster reef restoration projects use newly made concrete components and waste concrete as restoration substrate, the results are not satisfactory.

[0009] II. Influence of different types of cement concrete on marine plants and sessile organisms

[0010] At present, Portland cement concrete is almost used in marine concrete engineering, which has high alkalinity (pH value of pore solution is generally 12.0-13.0), while the pH value of seawater is usually 7.9-8.4. Because of the existence of alkali concentration gradient, the concrete in contact with seawater will continuously release alkali, thus increasing the pH value of seawater in this area and destroying the local ecosystem. It has great inhibitory effect on the settlement and growth of surface sessile organisms, especially for the organisms sensitive to alkalinity. Current domestic and foreign studies show that different types of cement concrete artificial reefs have significant differences in biological attachment effect. Aluminate cement and fly ash Portland cement artificial reefs have good biological attachment effect, and their alkalinity is lower than that of ordinary Portland cement concrete [1] . Similarly, the addition of 40%-60% fly ash and slag powder in cement concrete has good ecological effect. In addition, the types and quantity of sessile organisms attached on geopolymer cement concrete are more than those on cement concrete, and the higher the content of geopolymer cement, the better the ecological effect. The United States builds ecological concrete engineering using low-alkalinity cement concrete, such as aluminate cement, especially slag Portland cement, in which the slag replacement amount is up to 50%, which has good ecological effect of enriching marine plants and animals [2,3] . By using cement with low alkalinity to prepare concrete, the amount and density of oysters can be effectively improved, but the amount and density of oysters can be effectively improved.

[0011] III. Influence of calcium substances on the settlement of marine sessile organisms

[0012] Domestic and foreign studies have shown that the chemical element composition of the settlement substrate significantly affects the settlement, metamorphosis and later growth of oyster larvae. The most commonly used calcium-containing substrates (limestone and concrete) can effectively induce the settlement of oyster larvae, and their induction effect is comparable to that of shell. This shows that calcium element plays a crucial role in the settlement, metamorphosis and growth of oyster larvae.

[0013] Recently, in addition to the conventional substrate, people study the addition of calcium substances in cement-based materials, by increasing the content of calcium element in concrete, to study the attachment of oyster larvae. In the literature, 80 mesh cattle bone powder, calcium carbonate powder and gypsum powder (doping amount is 62.5% and 375% of the weight of cement) are mixed into the mortar to conduct oyster attachment experiment, and the order of the induction ability of calcium excipient under the same conditions is: cattle bone powder>calcium carbonate=sulfate; The calcium carbonate powder is 5% to 60% of the weight of the mortar (41.7% to 500.0% of the weight of the cement), and the effect is the best when the dosage is 20% (166.7% of the weight of the cement). Although by adding cattle bone powder, calcium carbonate powder and gypsum powder, the attachment amount of oysters can be increased, but the proportion of the added is too large (the weight of calcium powder is more than 41.7% of the weight of cement, even up to 500.0%), which seriously affects the mechanical properties and durability of concrete, and is not suitable for concrete engineering in marine environment. In addition, although cattle bone powder has a good induction effect on oyster attachment, but when the dosage exceeds 10% of the cement, it will make the concrete mildew. Therefore, although the cattle bone powder, calcium carbonate and other calcium substances are added in the concrete, the influence of marine environment on the durability of concrete structure is not considered, which makes it impossible to apply in harsh marine environment.

[0014] In CN104529286 patent: from the perspective of waste utilization, 5mm to 8mm oyster shell fragments of 10% to 20% of the cement quality are mixed in the artificial reef, to obtain a concrete that does not affect biological attachment and does not pollute the environment. CN104938384 simultaneously mixes 150 to 200 mesh biological calcium carbonate powder (fish bone, coral, eggshell and shell = 1:1:1:1) and shell fragments of 10% to 20% of the cement quality in the artificial reef, which shows that with the increase of calcium carbonate content, the induced biological mass gradually increases, and the maximum biological mass (marine plants and marine organisms) is collected when the calcium carbonate content is 20% of the weight of the cement. Similarly, to reduce the alkalinity of the surface of the concrete artificial reef, to make the microorganisms and algae more easily attached, to increase the biomass and population, and to better collect fish. The eluate of the biological calcium carbonate cement mortar covering layer is harmless to the environment and organisms. Although the biological calcium carbonate powder and oyster shell fragments are mixed into the concrete to make artificial reefs and conduct biological attachment experiments, the biological calcium carbonate powder indeed enhances the enrichment of organisms, but mainly enriches marine plants and microorganisms.

[0015] In summary, calcium content is crucial for the attachment of oyster larvae, and current experimental results also demonstrate that adding an appropriate amount of calcium carbonate to cement-based materials can promote the attachment and growth of oyster larvae. However, cement concrete contains a large amount of calcium ions, and the pH value of the pore solution is generally greater than 12.5. The pH value of a saturated calcium hydroxide solution is about 12 at room temperature, so the calcium ion concentration in the concrete pore solution is approximately 5 mmol / L; while the solubility of calcium carbonate is very low, only 9.5 × 10⁻⁶ at 25℃. -5 mol / L (9.5×10 -2 (mmol / L). Currently, the optimal calcium ion concentration range for inducing shellfish attachment is considered to be 10–25 mmol / L. Even when oyster larvae are placed in a saturated calcium carbonate solution, there is still insufficient calcium... 2+ The concentration provides suitable Ca for oyster attachment. 2+ Concentration. Furthermore, Ca(OH)₂ inside cement concrete can be released relatively quickly, while the dissolution of calcium carbonate requires a longer time. Therefore, it can be determined that adding calcium carbonate materials to concrete promotes the attachment of oyster larvae. 2+ It does not play a leading role.

[0016] Furthermore, excessive amounts of shell powder, with the weight ratio of shell powder to cement exceeding 10% and sometimes even reaching 500%, have a significant impact on concrete durability. While appropriate amounts of calcium carbonate materials can maintain or even improve the impermeability of concrete, excessive amounts are highly detrimental to concrete's resistance to sulfuric acid and sulfate corrosion in seawater.

[0017] Therefore, there are still many problems with using calcium-based substances such as bio-calcium carbonate, bovine bone meal, and calcium carbonate powder to incorporate into concrete for inducing the attachment of marine sessile organism larvae, especially the problems caused by excessive calcium content in concrete performance and mold growth caused by the incorporation of bovine bone meal.

[0018] IV. The Influence of Color on the Attachment of Marine Sessile Organisms

[0019] Substrate color has a certain influence on the attachment, metamorphosis, and growth of marine sessile larvae. International studies have reported that dark substrates promote oyster growth in colder waters. Domestic research indicates that oyster larvae exhibit color selectivity. The color selectivity of Hong Kong giant oyster larvae for plastic substrates is: black > white > red. Long oyster larvae prefer to attach to black and gray plastic substrates, suggesting that black and gray may be a form of camouflage to avoid predators. Barnacles prefer to attach to red substrates. Pearl oysters also prefer dark (black, red) and non-reflective substrates, exhibiting photosensitive behavior. Furthermore, the bacteria *Alteromonas calwellii* attract oyster larvae by producing a compound involved in melanin synthesis.

[0020] At present, the research on the influence of the color of the substrate on the settlement of marine sessile organism larvae is limited to organic polymer substrates such as plastic plates, polyethylene plates and asbestos plates. As a most potential alternative substrate, concrete is particularly used for oyster reef restoration, construction of artificial ecological engineering and corrosion protection of marine reinforced concrete. However, there is no relevant information on the influence of the color of the concrete on the settlement of sessile organism larvae.

[0021] V. Influence of roughness on the settlement of marine sessile organism larvae

[0022] Generally, the roughness of the surface of the settlement substrate has a certain influence on the settlement of oyster and barnacle larvae. Domestic and foreign researches show that, under the same conditions, the number of oyster and barnacle larvae settled on the rough surface is more than that on the smooth surface. The rough surface provides better tactile stimulation for the crawling and settlement of oyster and barnacle larvae, helps the larvae to stay on the substrate, protects the larvae from predators, and has a larger area and a potentially more abundant and diverse microbial environment than the smooth surface. The latest research shows that the settlement of marine organisms on the textured concrete surface is more than that on the smooth surface, which can promote the settlement and metamorphosis of larvae. However, some researches show that the roughness has no significant influence on the settlement and metamorphosis of larvae.

[0023] In summary, although the above researches have been carried out, such as the influence of different substrates, color and roughness on the settlement of marine sessile organisms, and the influence of the incorporation of calcareous materials into concrete on the settlement of marine sessile organisms has been recently studied. However, due to the great difference in knowledge of marine organisms, marine microorganisms, marine chemistry, marine concrete engineering materials and structure and other related disciplines, many problems are encountered in cross-research, such as the unclear water-cement ratio of cement-based materials, the unclear induction mechanism of oyster settlement of calcium carbonate materials, the excessive addition of calcium powder in cement, the serious durability problem of concrete, the easy mold of added bone powder and other problems. In addition, the professional and technical personnel of marine concrete engineering materials and structure lack the professional knowledge required for the settlement of marine sessile organisms. Therefore, the cooperation of multi-disciplinary professional and technical personnel is needed to solve many problems. SUMMARY

[0024] The purpose of the present application is to solve the problems of excessive addition of calcium materials, poor durability of concrete and low efficiency of inducing oyster larvae settlement in the concrete substrate with single addition of calcium materials, and to provide a high-durability fiber-reinforced ecological concrete for inducing sessile organisms to quickly and densely settle on the surface of the concrete and a preparation method thereof.

[0025] The invention is achieved in that the invention uses low-alkalinity cement, and adds dark pigments, biological calcium powder, calcium carbonate powder, trace elements, short fibers and controls the permeability of the concrete in the concrete, so that the concrete has high induced oyster larvae attachment and metamorphosis ability, and ensures the high durability of the concrete, and is pollution-free to the marine environment.

[0026] The invention also includes the following structural features:

[0027] The material components include: cementitious materials, gravel, sand, water, dark pigments, biological calcium powder, calcium carbonate powder, trace elements, short fibers and superplasticizer, and the weight ratio is 12.5%-22.0%, 39.4%-49.8%, 24.9%-37.3%, 6.2%-8.7%, 0.2%-1.7%, 0.15-1.0%, 0.15-1.0%, 0.1%-1.0%, 0.1%-1.0% and 0.02%-0.1%, respectively.

[0028] Preferably, the dark pigments are one or two of black iron oxide, aniline black, carbon black, antimony sulfide, red iron oxide, and organic pigment red. And according to the degree of influence on the performance of the concrete, the pigments are modified, and one of transparent resin, organosilicon, dimethylsiloxane and super-hydrophobic material is used for modification treatment.

[0029] Preferably, the biological calcium powder is one or a combination of several of the following: bovine bone powder, biological calcium carbonate powder including oyster shell powder, fish bone powder, eggshell powder, and coral powder, and the fineness is 100-1000 mesh.

[0030] Preferably, the modification method of the biological calcium powder is to treat 100-500 mesh eggshell powder, coral powder, oyster shell powder and fish bone powder with one or two of the following acids: acetic acid, acetic acid, silicic acid and sulfurous acid; and to treat 100-500 mesh bovine bone powder with one or two of the following acids: diluted phosphoric acid, sulfuric acid, hydrochloric acid and nitric acid.

[0031] Preferably, the calcium carbonate powder is one or a combination of several of the following: calcite, chalk, limestone, marble, aragonite, calcareous tufa powder, and processed light calcium carbonate, active calcium carbonate, calcium carbonate whiskers and ultra-fine light calcium carbonate, and the fineness is greater than 200 mesh.

[0032] Preferably, the trace elements are zinc, iron, potassium and phosphorus, which can be selected from natural minerals, industrial products or chemical reagents, including one or more of zinc sulfate, calcium phosphate, zinc phosphate, potassium sulfate, potassium nitrate, iron sulfate, ammonium sulfate, potassium phosphate, ammonium phosphate, iron phosphate, and modified to achieve slow release of corresponding ions and reduce or eliminate the adverse effects on the performance of concrete. However, for eutrophic areas, substances containing nitrogen and phosphorus elements are not selected.

[0033] Preferably, the short fiber is one or more of inorganic fiber (12-40mm long), such as basalt fiber, glass fiber, carbon fiber.

[0034] Preferably, the cementitious material is one of a silicate cement with mineral admixtures, a sulphoaluminate cement and an alkali-activated cementitious material. The mineral admixtures in the silicate cement with mineral admixtures include one or more combinations of silica fume, slag powder and fly ash; the sulphoaluminate cement includes one or two of fast-hardening sulphoaluminate cement, high-strength sulphoaluminate cement and expansive sulphoaluminate cement; and the alkali-activated cementitious material is one of alkali-activated slag and alkali-activated slag + fly ash.

[0035] Preferably, the sand is one or more of river sand, machine-made sand (parent rock is basalt or granite) or desalination sea sand.

[0036] A preparation method of the fiber-reinforced ecological concrete comprises the following steps:

[0037] S1: accurately weighing the cementitious material, gravel, sand, water, dark pigment, biological calcium powder, calcium carbonate powder, trace elements, short fibers and superplasticizer;

[0038] S2: first, the gravel and sand are put into a concrete mixer and stirred for 0.5-1 minutes; then, the cementitious material, dark pigment, biological calcium powder, calcium carbonate powder and trace elements are added and stirred for another 0.5-1 minutes; then, the short fibers, water and superplasticizer are added and stirred for 3-8 minutes; after uniform stirring, pouring and vibrating are performed, and then standard curing for 28 days or curing according to actual conditions, so that the fiber-reinforced ecological concrete is prepared.

[0039] The present application has the advantages that: the purpose of the present application is to induce the attachment of sessile organisms, mainly oysters, and to consider the attachment of barnacles when reinforcing concrete in the tidal zone. By controlling the use of dilute acid modification and composite grinding technology, the inducing ability of the bone meal is fully utilized, the bone meal content is greatly reduced, and the corrosion protection and modification are performed, so that the composite inducer mainly composed of bone meal is realized, the content is small, which almost does not affect the strength and permeability of the concrete, has strong oyster larvae attachment capacity, and solves the mold problem of the concrete. BRIEF DESCRIPTION OF DRAWINGS Attached Figure Description

[0041] Figure 1 The mold growth on concrete surfaces is observed in different mix proportions with 10% cow bone meal added.

[0042] Figure 2 It refers to different proportions of modified 10% bovine bone meal with a fineness greater than 200 mesh;

[0043] Figure 3 This refers to the oyster larvae attachment status in the laboratory benchmark concrete mix design.

[0044] Figure 4 The results show the attachment of oyster larvae to a compound inducer mainly composed of bovine bone meal in the laboratory.

[0045] Figure 5 This is a schematic diagram of a 210-day sea attachment experiment.

[0046] Figure 6 This is a schematic diagram of a 300-day sea attachment experiment. Detailed Implementation

[0047] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0048] These embodiments are for illustrative purposes only and do not limit the scope of the invention. Embodiments 1-22 are implemented using the same method, but their concrete mix proportions are as follows:

[0049] Example 1: Mix proportion of ordinary silicate cement concrete, the weight ratios of ordinary silicate cement, crushed stone, sand, water and polycarboxylate superplasticizer powder are 17.1%, 46.67%, 29.0%, 7.2% and 0.03% respectively.

[0050] The parent rock of the crushed stone is either basalt or diabase, with a maximum particle size not exceeding 50 mm and good gradation; the sand is one or more of river sand, manufactured sand (parent rock being either granite or basalt), or desalinated sea sand, and is well-graded. The water should meet the standard for concrete water (JGJ63-2006), Cl - With a content <1000mg / L and a pH value >4.5, it has little impact on the initial setting time difference, final setting time, strength, and permeability of cement. Furthermore, the materials selected in Examples 1-22 are the same.

[0051] Example 2: The standard concrete mix proportions are as follows: ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate superplasticizer powder are 10.26%, 0.86%, 5.98%, 46.67%, 29.0%, 7.2%, and 0.03% respectively.

[0052]

[0053] The above examples show that the incorporation of blast furnace slag powder and silica fume into concrete not only fills the interstitial space between cement particles, but also causes pozzolanic reaction, thereby improving the microstructure of the transition zone interface. This not only ensures the basic strength of the concrete, but also reduces the alkalinity and permeability of the concrete itself. While achieving the effect of reducing the alkalinity difference between the concrete and the seawater it contacts, the low permeability also controls the release rate of alkali, and finally makes it easier for oyster larvae to attach to the surface of the concrete.

[0054] Example 3: The weight ratio of unmodified dark pigment, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder is 0.51%, 10.26%, 0.79%, 5.54%, 46.67%, 29.0%, 7.2%, 0.03% respectively.

[0055] Example 4: The weight ratio of unmodified dark pigment, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder is 0.86%, 10.26%, 0.75%, 5.23%, 46.67%, 29.0%, 7.2%, 0.03% respectively.

[0056] Example 5: The weight ratio of unmodified dark pigment, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder is 1.37%, 10.26%, 0.68%, 4.79%, 46.67%, 29.0%, 7.2%, 0.03% respectively.

[0057] Example 6: The weight ratio of modified dark pigment (black iron oxide: aniline black mixture mass ratio = 1:1), ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder is 0.51%, 10.26%, 0.79%, 5.54%, 46.67%, 29.0%, 7.2%, 0.03% respectively.

[0058] Example 7: The weight ratio of modified dark pigment (black iron oxide: aniline black mixture mass ratio = 1:1), ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder is 0.86%, 10.26%, 0.75%, 5.23%, 46.67%, 29.0%, 7.2%, 0.03% respectively.

[0059] Example 8: modified dark pigment (mass ratio of black iron oxide: aniline black mixture = 1:1), ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducer powder weight ratio is: 1.37%, 10.26%, 0.68%, 4.79%, 46.67%, 29.0%, 7.2%, 0.03% respectively.

[0060] Among them, the modified dark pigment is mixed with 3% curing agent and 1.5% accelerator with the pigment, and the volume ratio of pigment to resin is 1:0.2; Curing at room temperature for 4h, 60℃ for 4h, then knock, use vibration mill grinding, fineness greater than 400 mesh.

[0061]

[0062] The permeability of black pigment to concrete has a great influence, and with the increase of the amount, the oyster larvae attachment amount decreases. On the one hand, the increase of the permeability of concrete increases the leaching of alkali of concrete, on the other hand, the iron oxide in it may be converted into iron ion, which increases the concentration of iron ion and inhibits the attachment of oyster larvae. In view of this problem, the resin coated pigment is ground into powder, which can greatly improve the impermeability of concrete, especially when the amount is 1.37%, the electric flux increases by only 3.2%. At the same time, with the increase of dark pigment, the oyster attachment continues to increase, which is different from the modified before the amount is 1.37%, which shows that the oyster larvae attachment rate decreases.

[0063] Example 9: unmodified bone meal, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducer powder weight ratio is: 0.51%, 10.26%, 0.79%, 5.54%, 46.67%, 29.0%, 7.2%, 0.03% respectively.

[0064] Example 10: unmodified bone meal, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducer powder weight ratio is: 0.86%, 10.26%, 0.75%, 5.23%, 46.67%, 29.0%, 7.2%, 0.03% respectively.

[0065] Example 11: unmodified bone meal, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducer powder weight ratio is: 1.37%, 10.26%, 0.68%, 4.79%, 46.67%, 29.0%, 7.2%, 0.03% respectively.

[0066] Example 12: Modified cow bone powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder weight ratio in turn: 0.51%, 10.26%, 0.79%, 5.54%, 46.67%, 29.0%, 7.2%, 0.03%.

[0067] Example 13: Modified cow bone powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder weight ratio in turn: 0.86%, 10.26%, 0.75%, 5.23%, 46.67%, 29.0%, 7.2%, 0.03%.

[0068] Example 14: Modified cow bone powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder weight ratio in turn: 1.37%, 10.26%, 0.68%, 4.79%, 46.67%, 29.0%, 7.2%, 0.03%.

[0069] 100 mesh cow bone powder is added to a 2% concentration phosphoric acid solution, the weight ratio of the two is 1:3, the temperature is 20-30°C, stirring in a speed of 200-500 rpm for 30 minutes, centrifugation in a centrifuge of 3000-5000 rpm for 3 minutes, pour off the supernatant, and wash the solid material with water 2-3 times, the washing water does not show acidity; the solid material after centrifugation is dried at 40°C under vacuum, the dried cow bone powder is mixed with slag powder at 1:4, and is ground to a fineness of more than 200 mesh with a vibration mill.

[0070]

[0071] Note: The modified cow bone powder is ground to 200-300 mesh

[0072] The cow bone powder is difficult to grind, and it is usually difficult to continue grinding to 100 mesh or less. Here, the 100 mesh cow bone powder is first chemically modified with 2% dilute phosphoric acid, then the dried cow bone powder is mixed with slag powder at 1:4, and is ground to a fineness of more than 200 mesh with a vibration mill. The modified cow bone powder increases its contact with alkaline substances in concrete, and the microstructure of concrete is more compact, and there is no moldy phenomenon as before. After modification, the permeability of concrete is also improved at low dosage. Even at a dosage of 1.37%, the electric flux increases by only 4.2%, and the attachment rate of oyster larvae increases from 205% to 400%.

[0073] Example 15: Modified bovine bone powder, modified dark pigment (mass ratio of black iron oxide: aniline black mixture = 1:1), oyster shell powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder weight ratio in turn: 0.51%, 0.86%, 0.51%, 10.26%, 0.62%, 4.34%, 46.67%, 29.0%, 7.2%, 0.03%.

[0074] Example 16: Modified bovine bone powder, modified dark pigment (mass ratio of black iron oxide: aniline black mixture = 1:1), oyster shell powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder weight ratio in turn: 0.86%, 0.86%, 0.51%, 10.26%, 0.58%, 4.03%, 46.67%, 29.0%, 7.2%, 0.03%.

[0075]

[0076] This example is based on the reference concrete, composite mixed with dark pigment, oyster shell powder, bovine bone powder, provides the necessary Ca 2+ for oyster attachment and metamorphosis by reference concrete, and has low alkalinity; at the same time, the dark pigment makes the concrete color darker, absorbs almost all visible light, and the concrete surface becomes black, providing a dark environment; the addition of shell powder and bovine bone powder provides the necessary HCO3 - , PO4 3- and various trace elements for oyster attachment, which together promote oyster attachment, so that oyster larvae can attach at a rate of 317% when the dark pigment is 0.86%, the oyster shell powder is 0.51%, and the bovine bone powder is 0.51%. When the dark pigment is 0.86%, the oyster shell powder is 0.51%, and the bovine bone powder is 0.86%, the attachment rate increases by 517%.

[0077] Example 17: Calcium carbonate powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder weight ratio in turn: 0.51%, 10.26%, 0.79%, 5.54%, 46.67%, 29.0%, 7.2%, 0.03%.

[0078] Example 18: Calcium carbonate powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder weight ratio in turn: 0.86%, 10.26%, 0.75%, 5.23%, 46.67%, 29.0%, 7.2%, 0.03%.

[0079] Example 19: The weight ratio of calcium carbonate powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder is 1.37%, 10.26%, 0.68%, 4.79%, 46.67%, 29.0%, 7.2%, 0.03%, respectively.

[0080]

[0081] In this example, 600 mesh calcium carbonate powder is used to replace mineral admixtures in equal amounts. With the increase of calcium carbonate powder content, the impermeability of concrete decreases, but the electric flux of concrete is lower than the reference value. Even at a dosage of 1.37%, it is still better than the impermeability of the reference group. With the increase of calcium carbonate powder content, the probability of calcium carbonate dissolution in concrete increases, resulting in an increase in the attachment change rate. Specifically, when the dosage is 0.51%, 0.86% and 1.37%, respectively, the attachment change rate of oyster larvae increases by 20%, 40% and 50%, respectively.

[0082] Example 20: The weight ratio of zinc sulfate, modified dark pigment (black iron oxide: aniline black mixture mass ratio = 1:1), modified cow bone powder, calcium carbonate powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder is 0.3%, 0.86%, 0.86%, 0.51%, 10.26%, 0.54%, 3.77%, 46.67%, 29.0%, 7.2%, 0.03%, respectively.

[0083] Example 21: The weight ratio of zinc sulfate, modified dark pigment (black iron oxide: aniline black mixture mass ratio = 1:1), modified cow bone powder, calcium carbonate powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylic acid water reducing agent powder is 0.6%, 0.86%, 0.86%, 0.51%, 10.26%, 0.50%, 3.51%, 46.67%, 29.0%, 7.2%, 0.03%, respectively.

[0084] The modified zinc sulfate is prepared as follows: select diatomite with SiO2 content > 90%, fineness 600 mesh, add 150 g water to a stirrer at 60°C, then add 100 g zinc sulfate, stir until dissolved, and wait for use; then add 150 g of the above diatomite to the solution heated to 60°C, stir in a stirrer at a speed of 200-500 rpm for 10 minutes, then dry in a drying oven at a temperature of 100°C. The modified zinc sulfate is obtained.

[0085]

[0086] The present example is based on the reference concrete, and the zinc sulfate, the bone meal, the calcium carbonate powder and the dark pigment are added. The reference concrete provides the necessary Ca 2+ for the oyster attachment and metamorphosis, and has low alkalinity. The dark pigment makes the concrete color darker, absorbs almost all the visible light, and the concrete surface becomes black, providing a dark environment. The bone meal and the calcium carbonate powder provide the necessary HCO3 - , PO4 3- and various trace elements in the bone meal, and the zinc sulfate provides Zn 2+ which can promote the early attachment of oyster larvae. The above gives all-round satisfaction to the ions and dark color required for the early induction of oyster larvae attachment and metamorphosis, and good results are obtained. When the dark pigment is 0.86%, the bone meal is 0.51%, the calcium carbonate powder is 0.51%, and the zinc sulfate is 0.3%, the attachment change rate can reach 580%. When the dark pigment is 0.86%, the bone meal is 0.86%, the calcium carbonate powder is 0.51%, and the zinc sulfate is 0.6%, the attachment change rate is 652%.

[0087] Example 22: The weight ratio of zinc sulfate, modified dark pigment (black iron oxide: aniline black mixture mass ratio = 1:1), modified bone meal, calcium carbonate powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water, chopped fiber and polycarboxylic acid water reducer powder is 0.6%, 0.86%, 0.86%, 0.51%, 10.26%, 0.50%, 3.51%, 46.42%, 28.85%, 7.2%, 0.4%, 0.03% respectively.

[0088] The implementation method of examples 1-22 is as follows:

[0089] According to the above preparation method of the fiber reinforced ecological concrete, three Φ100x50mm cylindrical specimens and five 200x200x30mm cuboid specimens are prepared, which are used to test the 28d chloride ion permeability of the concrete and the oyster larvae attachment and metamorphosis in the laboratory after 28d standard curing. The specific operation steps are as follows:

[0090] (I) specimen forming

[0091] 1. Calculate and accurately weigh the ordinary Portland cement, mineral admixture, crushed stone, sand, water, calcium carbonate powder, trace elements, dark pigment, biological calcium powder, chopped fiber and polycarboxylic acid water reducer powder according to the above mass.

[0092] 2. First, put the gravel and sand into the concrete mixer and stir for 0.5-1 minute; then add Portland cement, mineral admixtures, calcium carbonate powder, trace elements, biological calcium powder, and dark pigments, and continue stirring for 0.5-1 minute; then add chopped fibers, water, and superplasticizer and stir for 2-6 minutes; after stirring evenly, pour, vibrate, and remove the mold to obtain 3 Φ100x50mm cylindrical specimens and 5 200x200x30mm cuboid specimens; finally, place them in a standard curing room for 28 days, and at each age, evaluate the corresponding permeability, and after 28 days, perform laboratory oyster larvae attachment and metamorphosis experiments.

[0093] (II) The specific steps of the rapid chloride ion permeation experiment are as follows:

[0094] According to the standard "Standard Test Method for Electrical Indication of Concrete's Ability to Resist Chloride Ion Penetration" (ASTM1202-2017), after 28 days of standard curing, 3 Φ100x50mm cylindrical specimens are taken out of the curing room, and the surface moisture and debris are cleaned. After the surface is dry, a thin layer of epoxy resin is applied to the side of the cylindrical specimen. Then, the specimen is placed in a vacuum water saturation machine for 20-24 hours. Then, the specimen is cleaned and placed in a plexiglass mold, and the sealing between the specimen and the mold is checked. Then, 3% sodium chloride solution (electrode connected to the negative electrode of the power supply) and 0.3 mol / L sodium hydroxide solution (electrode connected to the positive electrode of the power supply) are added to the two sides of the mold. Then, start the experimental instrument, record the experimental data after 6 hours, and repeat the above operation for the last two specimens. Finally, calculate the strength according to the specification.

[0095] (III) The specific steps of the indoor oyster larvae attachment and metamorphosis experiment are as follows:

[0096] After 28 days of standard curing, 200x200x30mm cuboid specimens are taken out of the curing room, and the surface moisture and debris are cleaned. Then, they are placed in a test pool, and the seawater in the pool is sand-filtered Yellow Sea seawater with a salinity of about 32%-34%. After the water level of the seawater is higher than the concrete specimens, oxygen pipes are evenly distributed in the test pool, and oyster larvae are ready to be released.

[0097] And in the beginning of the induction of oyster attachment test, the seawater in the test tank is replaced daily, the water replacement amount is 1 / 3 of the total capacity of the test tank, the screen (≥200 mesh) is blocked in the drain to prevent the unattached oyster larvae from flowing away with the water, the larvae on the screen are put into the test tank again, then the chlorella is fed at 9 o'clock and 19 o'clock every day, and the oyster attachment is observed.

[0098] After the test lasts for 30 days, the water in the test tank is discharged, the test piece is taken out, the number and survival rate of oysters on the surface of the test piece are counted and recorded, and the smooth bottom surface when the concrete is poured is taken into account.

[0099] Compared with several typical prior arts known at present, the characteristics of the present application are:

[0100] Compared with the comparative document 1 (a new type of concrete artificial reef and its preparation method CN104529286A), the difference lies in:

[0101] The purpose of the present application is different from that of the comparative document: although the comparative document 1 adds oyster shell powder in the concrete, its purpose is to utilize waste, repair and perfect the artificial reef.

[0102] Compared with the comparative document 2 (a bionic concrete artificial reef and its preparation method 2015CN104938384A), the difference lies in:

[0103] (1) The purpose of the present application is different from that of the comparative document 2: although the comparative document 2 adds oyster shell or oyster shell powder in the concrete, its purpose is mainly achieved through the bionics of the surface, collects fish, microorganisms and algae, increases the number of microorganisms to improve the water environment, and does not mention oysters. The purpose of the present application is to induce the attachment of sessile organisms, mainly oysters, and consider the attachment of barnacles when the reinforced concrete is prevented from corrosion in the tidal zone.

[0104] (2) The comparative document 2 points out that the biological calcium carbonate powder (150-200 mesh) with a cement content of 10% or less is not obvious for inducing attachment. But in the research process of the present application, the modified bovine bone powder and the biological calcium carbonate powder (fineness: 100-1000 mesh) are used, and the optimal amount of the bovine bone powder and the biological calcium carbonate powder is within 10% of the cementitious material.

[0105] (3) By modifying the bone powder and biological calcium carbonate powder, specifically, the eggshell powder between 100 mesh to 500 mesh, coral powder, oyster shell powder, fish bone powder is treated with the following acid, including one or two of acetic acid, vinegar acid, silicic acid, sulfurous acid; 100 mesh to 500 mesh bone powder is treated with the following acid, including one or two of dilute phosphoric acid, sulfuric acid, hydrochloric acid and nitric acid.

[0106] (4) The comparative document is difficult to construct by embedding oyster shells on the surface of concrete, and such a method cannot be used on every project surface, and the feasibility is low. The present application adds shell powder in concrete to induce sessile organisms to adhere, and the content of shell powder accounts for less than 10% of the mass of cementitious materials, which not only simplifies the construction but also greatly increases the amount of oyster adhesion.

[0107] (5) Under marine environment, in recent years, there have been many phenomena of serious corrosion of artificial reefs, which is mainly caused by the combined action of biological sulfuric acid secreted by anaerobic microorganism sulfur bacillus and acidic substances secreted by other bacteria. Therefore, the content of calcium carbonate with large fineness will cause serious acid corrosion.

[0108] Compared with the comparative document 3 (Fan Ruilang. The influence of substrate type on oyster adhesion, growth, population establishment and reef development[D]), the difference lies in:

[0109] (1) The comparative document 3 uses 80 mesh bone powder, calcium powder and gypsum powder, which are separately added to concrete. In the present application, the fineness of all calcium materials is greater than 100 mesh, which is greater than the fineness of the materials in the comparative document 3. Similarly, the bone powder is modified, and the particle size distribution of concrete and its induction ability are considered.

[0110] (2) Under normal temperature conditions, the bone powder is ground by a vibration mill, and when the fineness is greater than 80 mesh, the bone powder contains a large amount of collagen, which is seriously agglomerated and cannot be further ground. In the present application, the dilute acid modification technology is used, and the other substances are compounded and ground, so that the bone powder with small particle size and modified biological calcium powder with fineness greater than 200 mesh are obtained. The prepared biological calcium powder retains the original substances of biological calcium, increases the release rate of substances for inducing oyster larvae adhesion, and reduces the content of biological calcium powder, thereby reducing the influence on the performance of cement concrete.

[0111] (3) Because the bone powder contains a large amount of organic substances such as collagen, the large amount of these substances mixed will cause the decrease of concrete strength and impermeability, especially when the content is more than 5%, the increase of the content will rapidly decrease the concrete strength, significantly deteriorate the impermeability, and the concrete surface will grow mold under standard curing conditions. Figure 1 is the mold growth condition of the concrete test piece. Figure 2 is the surface condition of the modified concrete.

[0112] As can be seen from Figure 1 , the mold on the surface of the concrete is white and flocculent, and almost covers the entire surface of the concrete; under the same bone meal content, age, and curing conditions, Figure 2 , the surface of the concrete is not moldy.

[0113] The present application fully utilizes the induction capacity of the bone meal by controlling the modification with dilute acid and the composite grinding technology, greatly reduces the bone meal content, and performs the corrosion prevention treatment and modification, so that the composite inducer mainly composed of the bone meal is realized, the content of which is small, almost does not affect the strength and permeability of the concrete, has a strong oyster larvae attachment capacity, and solves the mold problem of the concrete. Compared with the concrete without adding the inducer, the concrete with the inducer has a significantly increased number of oyster larvae attachment, and the specific number is shown in Figure 3 and Figure 4 .

[0114] The comparative file and the consulted literature show that the calcium content is crucial for the attachment of the oyster larvae, and some experimental results also prove that adding an appropriate amount of calcium carbonate material in the cement-based material can promote the attachment and growth of the oyster larvae. However, there is a large amount of calcium ion in the cement concrete, the pH value of the pore solution is generally greater than 12.5, the pH value of the saturated calcium hydroxide solution is about 12 at normal temperature, and the calcium ion concentration in the pore solution of the concrete is about 5 mmol / L; and the solubility of the calcium carbonate is very small, which is only 9.5×10 -5 mol / L (9.5×10 -2 mmol / L) at 25℃. It is currently considered that the optimal range of the calcium ion concentration for inducing the oyster attachment is 10-25 mmol / L, and even if the oyster larvae are placed in the saturated calcium carbonate solution, there is not enough Ca 2+ concentration to provide a suitable ion concentration for the oyster attachment. Further, the Ca(OH)2 in the cement concrete can be released quickly, and the dissolution of the calcium carbonate needs a long time. Therefore, it can be determined that adding the calcium carbonate material in the concrete to promote the attachment of the oyster larvae, Ca 2+ does not play a leading role. The early attachment and metamorphosis of the oyster are related to HCO3 - , and the secondary shell of the calcium carbonate is generated together with Ca 2+ during the metamorphosis. After adding the calcium carbonate, Ca(HCO3)2 is generated by the reaction of the calcium carbonate with CO2 and water, and participates in the attachment, which is the fundamental mechanism of the promotion of the oyster larvae attachment.

[0115] There is an optimal amount of the calcium carbonate in the cement-based material, which can be explained from the following three aspects:

[0116] 1) for equal replacement of cement, with the increase of calcium carbonate content, the alkali in concrete is diluted, the total alkalinity is reduced, but with the increase of calcium carbonate content, the probability of dissolution of calcium carbonate in concrete increases, the content of HCO3 - in its solution increases, so as to promote the attachment and metamorphosis of oysters; but when the content is too large, the permeability of concrete increases sharply, the alkali and carbonate in concrete seeps out quickly, so that the negative effect of alkali is highlighted, and the critical or negative effect of carbonate is initially shown, so the attachment amount decreases;

[0117] 2) for equal replacement of aggregate, with the increase of content, the permeability of concrete decreases, which will lead to the decrease of seepage of calcium ion and OH - , but the permeation rate of carbonate ion will first gradually increase, and when it reaches a certain value, the attachment of oyster reaches the maximum; and with the continuous increase of content, the decrease of calcium ion is large, and the carbonate may also decrease, which will appear as the attachment of oyster larvae is limited by the concentration of calcium ion, and the attachment amount decreases;

[0118] 3) for equal replacement of mineral admixture, with the increase of content, the permeability increases, and due to the increase of calcium carbonate, the HCO3 - concentration required for oyster attachment reaches a suitable range, which shows that the attachment of oyster larvae increases; with the continuous increase of content of mineral admixture, the content of mineral admixture decreases, so the amount of seeped alkali and carbonate increases, but too much alkali and HCO3 - ion will inhibit the attachment of oyster larvae.

[0119] Compared with comparative document 4 (Li Zhenzhen, Gong Pihei, Guan Zhangtao, et al. Biological attachment effect of different cement types of concrete artificial reefs [J]. Fisheries Science Progress, 2017, 38(5): 57-63.), the difference lies in:

[0120] The composite Portland cement, slag Portland cement, pozzolanic Portland cement, fly ash Portland cement and aluminate cement are used in comparative document 4: the composite addition of ordinary Portland cement and mineral admixture is adopted in the present application to realize low-alkalinity cement; the silica fume is one of the mineral admixtures with high activity, and the appropriate amount of the silica fume has obvious effect on the durability improvement of reinforced concrete under marine environment; through optimization design and experiment, the low-alkalinity cement with high strength and durability can be obtained. Meanwhile, the high impermeability of silica fume concrete is utilized, and even if the internal alkalinity of the concrete is high, there are still a large number of oyster larvae to attach, metamorphose and grow. The composite of low-alkalinity sulphoaluminate cement is adopted to control the alkalinity of the cement concrete, and to provide suitable pH value for the oyster larvae attachment. In addition, the marine plants and oysters, barnacles and other sessile organisms have different alkali tolerance, and the environment required in the attachment period and the post-period is different. For example, the attachment, metamorphosis and post-growth of barnacles and oysters require a large amount of calcium ions.

[0121] The concrete in comparative document 4 is used to enrich marine organisms, and the main starting point is the size and diversity of the attached organisms, and the main attached organisms are various algae. The research purpose in the present application is to induce oyster attachment, but the tolerance of oysters and barnacles to alkalinity is higher than that of algae, and a large amount of calcium ions is required for the attachment and metamorphosis of oysters. Therefore, although the two kinds of concrete seem to be the same, there are great differences between them. Figure 5 and Figure 6 are the comparisons of the biological attachment after comparative document 4 and the present application are subjected to about 210d and 300d of real sea attachment experiment respectively.

[0122] Therefore, since this part of knowledge involves the intersection of marine sessile organisms, marine plants and marine concrete engineering disciplines, neither the technical personnel in the field of concrete and engineering nor the technical personnel in the field of marine biology can obtain the technical features in the present application that the balance between the reduction of concrete alkalinity and the concentration of calcium ions is closely related to the attachment of marine sessile organisms through comparative document 1.

[0123] In addition, the unique features and beneficial effects of the present application are as follows:

[0124] Dark pigment

[0125] The light-avoiding characteristics of oyster eye-spot larvae are utilized, and the dark pigment (one or two of black iron oxide, aniline black, carbon black, antimony sulfide, red iron oxide and organic pigment red) is added into the concrete to change the color of the concrete, make the color of the concrete darker, let the oyster larvae think that it is a dark environment, induce the oyster larvae to reach the surface of the dark concrete, increase the contact probability of the larvae and the surface of the concrete, and realize the increase of the oyster larvae induced attachment rate. Specifically:

[0126] Marine biologists, in order to cultivate and proliferate or eliminate undesirable populations, consider the use of different colors of the substrate for the attachment of marine sessile organisms, which belongs to the discipline of marine biology. It is quite different from the discipline of marine concrete engineering or concrete materials, and is completely two different disciplines. Through the intersection of marine sessile organisms and concrete disciplines, the use of dark concrete for oyster larvae induction attachment is obtained. In the invention, dark pigments are added to deepen the color of the concrete surface to promote the attachment of oyster larvae. The addition of other materials to concrete will affect the performance of concrete. The invention considers that the surface color of concrete made of different cements is different. Therefore, the amount of dark material is determined according to the type and amount of cement. Dark pigments also affect the performance of concrete. Most importantly, if dark pigments are added, the alkali and Ca 2+ Isotonic permeation rate, the released alkali will affect the attachment, metamorphosis and growth of sessile organism larvae, and when the amount is greater than a certain value, the amount of larvae attachment will decrease. In the invention, the impermeability of concrete is designed and controlled, and the main measures are: selection of dark pigment type, control of addition amount and modification. With the increase of the amount of dark material, the attachment rate of larvae first increases, and when the amount of cement is 0.5% to 6%, the attachment amount of larvae is the largest, but then it increases slightly or remains unchanged.

[0127] Trace elements

[0128] According to the fact that oysters enrich a large amount of zinc in their bodies, which is much higher than the seawater they live in, and also contain a large amount of Fe, P and K elements. At the same time, appropriate Zn 2+ , K + concentration in the solution can promote the early attachment and metamorphosis of oyster larvae. Therefore, zinc sulfate, potassium sulfate, potassium nitrate, iron sulfate, zinc phosphate, ammonium nitrate, potassium phosphate, ammonium phosphate, iron phosphate and calcium phosphate are used as trace elements and added to concrete, and through the modification of these substances, the strength and impermeability of concrete remain basically unchanged, and the induced attachment rate of oyster larvae is greatly increased. Specifically:

[0129] Marine biology researchers, in order to clarify the oyster attachment mechanism and the purpose of breeding and propagation, study the effects of different ions on the attachment and metamorphosis of marine sessile organisms, which belongs to the discipline of marine biology. It is quite different from the discipline of marine concrete engineering or concrete materials, and is completely two different disciplines. Through the intersection of marine sessile organisms and concrete disciplines, it is found that by adding corresponding substances to concrete, oyster larvae can be induced to attach to the surface of concrete. Because soluble salts have a great influence on the performance of concrete, such as affecting the early workability, setting time, and later strength and impermeability, the present application uses diatomite as a carrier to fix these inorganic salts inside the diatomite, reducing the influence of soluble salts on the performance of concrete. At the same time, the diatomite is used to improve the performance of concrete, so that the mechanical properties and impermeability of concrete can be maintained when these inducing substances are added. In addition, because diatomite has a slow-release effect as a carrier, the release of soluble salts is relatively slow, especially after a certain period of seawater immersion, the release rate is maintained at a very small rate. Therefore, this part of knowledge involves the intersection of marine sessile organisms, chemistry and marine concrete engineering disciplines. Neither the technical personnel in the field of concrete and engineering nor in the field of marine biology can obtain the technical features of the present application, i.e. adding trace elements to concrete, changing the ion content of trace elements on the surface of concrete, controlling the permeability of concrete and the close relationship between concrete with high oyster larvae attachment ability through the existing background.

[0130] Concrete permeability

[0131] The strength and permeability of concrete are the two most important properties of concrete. The addition of different inducers to the reference concrete will affect the properties of the concrete. Therefore, when considering the addition of different substances to promote the attachment, metamorphosis and later growth of oyster larvae, the overall control of the effect of the substances on the strength and permeability of the concrete must be considered first. Then, the compatibility of the raw materials is considered to select the raw materials. When the properties of the raw materials cannot meet the actual requirements, the raw materials are modified and then added to achieve the desired function. However, in the previous studies, the effect of the amount of calcium on the attachment of oyster larvae was considered, but the properties of the concrete itself, the water-cement ratio, the amount of calcium and curing were not considered. The change in the permeability of the concrete will change the rate of leakage of alkali and ions in the concrete. The poorer the impermeability of the concrete, the greater the leakage rate of alkali and ions in the concrete, which may increase exponentially. Therefore, the released alkali and ions will have a great impact on the larvae, and may change from promoting attachment to inhibiting attachment, especially when the amount of cement is large. Therefore, when the inducers are added to the concrete, the change in the impermeability of the concrete must be controlled within a certain range, such as a change of no more than 10%. In this way, the effects of the inducers can be compared. Otherwise, it is impossible to evaluate the effect of the single inducer or the combined addition of inducers on the induction of oyster larvae.

[0132] Only by mastering the optimal environment required by marine sessile organisms for attachment, metamorphosis and later growth, and by designing the concrete from the perspective of the impermeability of the concrete, rather than only considering the amount of various raw materials and ignoring the change in the impermeability of the concrete, can the knowledge in this part be obtained. Therefore, this part of knowledge also involves the intersection of marine sessile organisms, chemistry and marine concrete engineering disciplines. Neither the technical personnel in the field of concrete and engineering nor the technical personnel in the field of marine biology can obtain the technical features of the overall control of the impermeability of the concrete and the close relationship between the inducers and the ability of the oysters to efficiently induce attachment in the present invention through the existing background.

[0133] In addition, fibers can enhance the strength of concrete, especially the tensile strength. In the present invention, alkali-resistant fibers are combined with ecological concrete to enhance the crack resistance, bending resistance and fatigue resistance of the concrete. This can reduce the early cracking of concrete when used in breakwater components, and reduce the damage rate of the components during transportation and fixation at the sea, especially increasing the ability to resist extreme loads such as typhoons.

[0134] Therefore, since this part of knowledge involves the intersection of marine sessile organisms, marine plants and marine concrete engineering disciplines, neither the technical personnel in the field of concrete and engineering nor the technical personnel in the field of marine biology can obtain the technical features closely related to the deep color pigment incorporated into the concrete to change the color, the modification of the bone meal, the grinding technology and the control of the permeability of the concrete and the concrete with high efficient induction of oyster attachment ability and high durability in the present application through the prior art. And the technical features closely related to the balance between the alkalinity of the concrete and the calcium ion concentration and the attachment of the marine sessile organisms in the present application cannot be obtained through the prior art.

[0135] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A fiber-reinforced eco-friendly concrete, characterized in that: It is made of cementitious materials, crushed stone, sand, water, dark pigment, bio-calcium powder, calcium carbonate powder, trace elements, chopped fibers, and superplasticizer. The weight ratios of cementitious materials, crushed stone, sand, water, dark pigment, bio-calcium powder, calcium carbonate powder, trace elements, chopped fibers, and superplasticizer are as follows: 12.5%–22.0%, 39.4%–49.8%, 24.9%–37.3%, 6.2%–8.7%, 0.2%–1.7%, 0.15%–1.0%, 0.1%–1.0%, 0.1%–1.0%, and 0.02%–0.1%. The dark pigment is one or two of the following: iron oxide black, aniline black, carbon black, antimony sulfide, iron oxide red, and organic pigment red; The dark pigment is modified according to its impact on concrete performance, using one of the following modification methods: transparent resin, organosilicon, or superhydrophobic material. The bio-calcium powder is modified bovine bone powder; the modification method of the bio-calcium powder is: acid treatment of 100-500 mesh bovine bone powder, wherein the acid includes one or two of diluted phosphoric acid, sulfuric acid, hydrochloric acid and nitric acid; The calcium carbonate powder mentioned is one or more of the following: calcite, chalk, limestone, marble, aragonite, travertine powder, as well as processed light calcium carbonate, active calcium carbonate, calcium carbonate whiskers, and ultrafine light calcium carbonate, with a fineness greater than 200 mesh.

2. The fiber-reinforced eco-friendly concrete according to claim 1, characterized in that: The chopped fibers are inorganic fibers, 12-40 mm in length, including one or more of basalt fibers, alkali-resistant glass fibers, and carbon fibers.

3. The fiber-reinforced eco-friendly concrete according to claim 1, characterized in that: The cementing material is a silicate cement with added mineral admixtures, sulfoaluminate cement, or alkali-activated cementing material. The mineral admixtures in the silicate cement include one or more combinations of silica fume, slag powder, and fly ash. The sulfoaluminate cement includes one or two of rapid-hardening sulfoaluminate cement, high-strength sulfoaluminate cement, and expansive sulfoaluminate cement. The alkali-activated cementing material includes one of alkali-activated slag or a combination of alkali-activated slag and fly ash.

4. A method for preparing fiber-reinforced eco-friendly concrete as described in claim 1, characterized in that, Includes the following steps: S1: Accurately weigh cementitious materials, crushed stone, sand, water, dark pigments, bio-calcium powder, calcium carbonate powder, trace elements, chopped fibers and superplasticizers; S2: First, put crushed stone and sand into a concrete mixer and mix for 0.5 to 1 minute; then add cementitious materials, dark pigments, biological calcium powder, calcium carbonate powder and trace elements and continue mixing for 0.5 to 1 minute; then add short-cut fibers, water and superplasticizer and mix for 3 to 8 minutes; after mixing evenly, pour and vibrate, and then carry out standard curing for 28 days or curing according to the actual situation to obtain a fiber-reinforced ecological concrete.

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