CN111268962A - A kind of dark Portland cement concrete for inducing the attachment of marine sessile organisms and preparation method thereof - Google Patents

Abstract

The invention relates to a technology for inducing marine periphyton attachment, in particular to dark portland cement concrete for inducing marine periphyton attachment and a preparation method thereof, and belongs to the cross field of marine periphyton and marine concrete. The material composition of the invention is: portland cement, mineral admixture, broken stone, sand, water, dark pigment, biological calcium powder and a superplasticizer. The strength and permeability of concrete are the two most important properties of concrete. When considering that different substances are added to promote the adhesion, metamorphosis and later growth of oyster larvae, the strength and permeability of the concrete are not greatly influenced by the oyster larvae, and then raw materials are selected according to the compatibility of various raw materials.

Description

A kind of dark Portland cement concrete that induces marine sessile organisms to attach and its preparation method

technical field

The invention relates to a technology for inducing the attachment of marine sessile organisms, in particular to a dark Portland cement concrete for inducing the attachment of marine sessile organisms and a preparation method, belonging to the cross field of marine sessile organisms and marine concrete.

Background technique

Reinforced concrete is widely used in the construction of marine infrastructure, such as harbour terminals, sea-crossing bridges, marine platforms and undersea tunnels. However, the corrosion of steel bars caused by chloride ion corrosion greatly shortens the service life of reinforced concrete structures and brings a huge economic burden to the society. So far, for reinforced concrete engineering in marine environment, the representative anti-corrosion technologies mainly include high-performance concrete, surface coating, FRP reinforcement, steel rust inhibitor and electrochemical protection technology. These anti-corrosion technologies all have some shortcomings or deficiencies, such as difficult construction, insufficient durability of materials easy to age, long-term unpredictability, and high cost. In addition, most of the current anti-corrosion technologies are aimed at the splash zone, while the anti-corrosion in the tidal zone has the problems of few measures, high cost and poor anti-corrosion effect.

The surface of concrete works in the tidal zone is often covered with a large number of sessile organisms, such as oysters and barnacles. Studies have shown that the bio-glue secreted by oysters and barnacles can block the capillary pores on the concrete surface, hinder the entry and exit of ions and gases, improve the impermeability of concrete, and then improve its durability. . The use of marine sessile biological anticorrosion is not only active, economical and environmentally friendly, but also makes up for the limitations of the current reinforced concrete anticorrosion technology in the tidal zone and underwater area. This is the intersection of marine concrete and marine sessile biology, creating an emerging research field of reinforced concrete structure corrosion protection. However, in some sea areas, sessile organisms often appear sparsely attached, loosely attached or even without attachment due to the influence of the external environment. Therefore, inducing sessile organisms to attach quickly and densely to the concrete surface is the key to realize sessile organisms anti-corrosion.

At the same time, due to the rapid development of coastal economy in recent decades and the lack of attention to environmental protection, large-scale destruction of coastal ecology has been caused, and it has had a huge impact on the ecology and economy of my country's coastal areas. At present, with the introduction of a series of relevant national policies, my country's marine engineering construction will also usher in a peak period. At the same time, large-scale construction of marine engineering and breakwaters to ensure the stability of the surrounding sea areas will further damage the already fragile ecosystem of the ocean. If proper ecological protection is not taken, it will bring greater disaster to the ecology along the coast of the ocean. At the same time, most of the coastal infrastructure cannot be dismantled, and the ecology of the sea area needs to be restored, which makes people gradually realize that the application of ecological technology on a large number of infrastructure can effectively improve or restore the ecology of the sea area. Therefore, it is very important and urgent to construct concrete projects with good ecological effects, or to ecologicalize existing concrete projects to improve the offshore ecological environment. However, as of now, the ecological technology of projects in the tidal range such as breakwaters is still blank in China.

Oysters are "ecological engineers", and they are mainly concentrated in the tidal range and within 30 meters of water. At the same time, oysters like to attach to similar shells to form thick oyster reefs. Therefore, oysters are densely attached to the breakwater. Realize the ecologicalization of the breakwater; in addition, the current oyster reefs are severely damaged, and most of them need to be re-attached on a large scale to achieve ecological restoration. Therefore, both the construction of marine ecological engineering and the restoration of oyster reefs can realize their ecological functions through the mass reproduction of oysters. Therefore, how to make oysters attach, metamorphose and grow rapidly on these projects is crucial. The current domestic and foreign related researches are as follows:

1. Effects of ions on the attachment and metamorphosis of marine sessile larvae

Domestic and foreign research on marine ^sessile larvae attachment ^and metamorphosis induction mainly focus _on the effect of ^ion concentration in solution on it. Ions or substances can promote the attachment or metamorphosis of oysters at appropriate concentrations, but Cu ²⁺ has no obvious promoting effect, and even increases the mortality of larvae at high concentrations. K ⁺ induces larval metamorphosis by affecting the behavior of the cell membrane; NH ₃ enters the cell, leading to an increase in intracellular pH, which subsequently causes depolarization of neurons in the behavioral pathway, thereby inducing sessile metamorphosis. Although many studies on the attachment and metamorphosis of sessile organisms on the surfaces of polyethylene boards, shells, tiles and other materials have been carried out in solution, such methods are not easy to implement or the cost is too high when applied in actual marine concrete projects. .

At present, with the extensive application of concrete in marine engineering, especially the recent oyster reef restoration project, concrete has become the most commonly used substrate material for marine sessile organisms. But concrete materials are very different from traditional shells, limestone, rubber tires, and plastic panels. Concrete has high alkalinity, high calcium ions, and is also rich in other ions, such as potassium and sodium ions, which have a great impact on the attachment and growth of oysters. At present, although some oyster reef restoration projects use newly made concrete components and waste concrete as restoration substrates, the effect is not ideal.

2. Effects of different types of cement concrete on marine plants and sessile organisms

At present, almost all marine concrete projects use Portland cement concrete, which has high alkalinity (the pH value of the pore solution is generally 12.0 to 13.0), while the pH value of seawater is usually 7.9 to 8.4. Due to the presence of an alkali concentration gradient, concrete in contact with seawater will continue to release alkali, thereby increasing the pH of seawater in this area and destroying local ecosystems. It has a great inhibitory effect on the adhesion and growth of sessile organisms on its surface, especially for alkali-sensitive organisms, which has a great impact. Current research at home and abroad shows that different types of cement concrete artificial reefs have significant differences in the biofouling effect. Concrete has low alkalinity ^[1] . Similarly, adding 40%-60% fly ash and slag powder to cement concrete has a good ecological effect. In addition, there are more types and quantities of organisms attached to the cement concrete than cement concrete, and the higher the content of the cement cement, the better the ecological effect. The construction of ecological concrete projects in the United States uses low-alkalinity cement concrete, such as aluminate cement, especially slag Portland cement, of which 50% of the slag is replaced, which has a good ecological environment for enriching marine plants, animals, etc. Effects ^[2,3] . By formulating concrete with cement with lower alkalinity, alkali-sensitive biomass (mainly marine plants) can be effectively increased, but the increase in attachment amount and attachment density to oysters is limited.

3. Effects of calcium substances on the attachment of marine sessile organisms

Studies at home and abroad have shown that the chemical element composition of the attached substrate significantly affects the attachment, metamorphosis and later growth of oyster larvae. The most commonly used calcium-containing substrates (limestone and concrete) can effectively induce the attachment of oyster larvae, and the induction effect is comparable to that of shells. This indicates that calcium plays a crucial role in the attachment, metamorphosis and growth of oyster larvae.

Recently, in addition to conventional substrates, calcium substances have been added to cement-based materials to study the attachment of oyster larvae by increasing the calcium content in concrete. In the literature, 80-mesh bovine bone meal, calcium carbonate powder, and gypsum powder (with a dosage of 62.5% and 375% of the cement weight) were used alone in the mortar to conduct oyster attachment experiments. The order of induction ability is: bovine bone meal > calcium carbonate = calcium sulfate; the calcium carbonate powder dosage is 5% to 60% of the mortar weight (41.7% to 500.0% of the cement weight), and its dosage is 20% (for the cement weight) 166.7%) is the best. Although the adhesion of oysters can be increased by adding bovine bone meal, calcium carbonate powder and gypsum powder, the proportion of the added amount is too large (the weight of the calcium powder is greater than 41.7% of the cement weight, even reaching 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 the bovine bone meal has a good induction effect on the adhesion of oysters, when the amount exceeds 10% of the cement, it will make the concrete moldy. Therefore, although bovine bone meal, calcium carbonate and other calcareous substances are mixed into concrete at present, the influence of marine environment on the durability of concrete structure is not considered, so that it cannot be used in harsh marine environment at all.

In the CN104529286 patent, from the perspective of waste utilization, 5mm-8mm oyster shells with 10%-20% of the cement mass are mixed into the artificial reef to obtain a concrete that does not affect biological adhesion and does not pollute the environment. CN104938384 10%-20% of the cement quality is mixed with 150-200 mesh biological calcium carbonate powder (fish bone, coral, eggshell and shell = 1:1:1:1) and shell fragments at the same time in the artificial reef. With the increase of calcium carbonate content, the induced biomass gradually increased. When the content of calcium carbonate was the largest (20% of cement weight), the biomass (marine plants, marine organisms) attracted by biological calcium carbonate was the most. Similarly, in order to reduce the surface alkalinity of the concrete artificial reef, it is easier for microorganisms and algae to attach, and the biomass and population are increased, and the fish collection effect is better. The bio-calcium carbonate cement mortar cover layer is not harmful to the environment and organisms. Although bio-calcium carbonate powder, oyster shell fragments, etc. were mixed into concrete for artificial reef production and bio-fouling experiments, bio-calcium carbonate powder did enhance the enrichment of organisms, but the main enrichment was marine plants and microorganisms.

In conclusion, calcium content is very important for the attachment of oyster larvae, and some current experimental results also prove that adding an appropriate amount of calcium carbonate to cement-based materials can promote the attachment and growth of oyster larvae. However, there are a lot of calcium ions in cement concrete, the pH value in the pore solution is generally greater than 12.5, and the pH value of the saturated calcium hydroxide solution is about 12 at room temperature, so the calcium ion concentration in the concrete pore solution is about 5mmol/L; The solubility of calcium is very small, only 9.5×10 ^-5 mol/L (9.5×10 ^-2 mmol/L) at 25°C. At present, it is believed that the optimal range of calcium ion concentration for inducing shellfish attachment is 10-25 mmol/L. Even if oyster larvae are placed in a saturated calcium carbonate solution, there is not enough Ca ²⁺ concentration to provide suitable Ca ²⁺ for oyster attachment. concentration. Furthermore, the Ca(OH) ₂ in the cement concrete can be released quickly, while the dissolution of calcium carbonate takes a longer time. Therefore, it can be determined that the incorporation of calcium carbonate materials in concrete promotes the attachment of oyster larvae, and Ca ²⁺ does not play a dominant role.

In addition, the proportion of shell powder is too large, and the weight ratio of shell powder to cement is more than 10%, and some even reach 500%, which has a huge impact on the durability of concrete. Although the proper amount of calcium carbonate material can make the impermeability of the concrete not reduced or better, but the excessive amount is very unfavorable for the concrete to resist sulfuric acid corrosion and sulfate corrosion in seawater.

Therefore, there are still many problems in using calcium substances such as biological calcium carbonate, bovine bone meal and calcium carbonate powder to be mixed into concrete to induce attachment of marine sessile organism larvae. mold and other problems caused by entry.

4. The effect of color on the attachment of marine sessile organisms

The color of the substrate has a certain influence on the attachment, metamorphosis and growth of marine sessile larvae. It has been reported abroad that dark substrates can promote the growth of oysters in sea areas with lower temperatures. Domestic studies have shown that oyster larvae have certain selectivity to color. The color selectivity of Hong Kong giant oyster larvae to plastic anchorage is: black>white>red. Long oyster larvae were more inclined to attach to black and gray plastic plates, and it was thought that black and gray may be a protective color of oyster larvae to avoid predators. Barnacles like to cling to red substrates. Pearl oysters also prefer dark (black, red), non-reflective substrates, exhibiting photosensitive behavior. and Alteromonascalwellii bacteria attract oyster larvae by producing a compound involved in melanin synthesis.

At present, the research on the effect of substrate color on the attachment of marine sessile larvae is limited to organic polymer boards such as plastic boards, polyethylene boards, and asbestos boards. Concrete is one of the most potential alternative substrates, especially for the restoration of oyster reefs, the construction of artificial ecological projects, and the anti-corrosion of marine reinforced concrete. The effect of its color on the adhesion of sessile larvae has not been reviewed to the relevant information.

5. The effect of roughness on the attachment of marine sessile larvae

Generally speaking, the roughness of the attachment base has a certain influence on the attachment of oysters and barnacle larvae. Domestic and foreign studies have shown that under the same conditions, the oyster and barnacle larvae attached to the rough surface are more than those of the smooth surface. Rough surfaces provide better tactile stimulation for oyster and barnacle larvae to crawl and attach to assist larvae retention on the substrate; cracks and pits exist to protect larvae from predators; and compared to smooth surfaces, There are larger areas and potentially more abundant and diverse microbial environments. New research shows that textured concrete surfaces are more susceptible to marine life than smooth surfaces, which can promote attachment and metamorphosis of larvae. However, some studies have shown that roughness has no significant effect on larval attachment metamorphosis.

In conclusion, although the above studies have been carried out, such as the effect of different substrates, and color and roughness on marine sessile attachment, the effect of incorporating calcareous materials into concrete on marine sessile attachment has recently been studied. However, due to the knowledge of related disciplines such as marine organisms, marine microorganisms, marine chemistry, and marine concrete engineering materials and structures, the subject directions are very different, which makes cross-research encounter many problems, such as the cement-based materials mentioned above. The water-cement ratio is unclear, the mechanism of oyster adhesion induced by calcium carbonate materials is unclear, too much calcium powder is added to the cement and the durability of the concrete is seriously insufficient, and the added bovine bone powder is prone to mildew and many other problems. In addition, marine concrete projects Professional technicians of materials and structures lack the expertise required for marine sessile organisms to attach. Therefore, multidisciplinary professional and technical personnel are required to cooperate in order to solve many problems.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a fast and dense method for inducing sessile organisms to solve the problems of excessive mixing amount, serious poor durability of concrete, and low adhesion efficiency of inducing oyster larvae in the concrete substrate currently used with single calcareous material. Ground-adhering and highly durable concrete

The object of the present invention is achieved in this way: the present invention makes concrete by using low alkalinity Portland cement mixed with mineral admixtures, and adding dark pigments, biological calcium powder and controlling the permeability of concrete in concrete. It has a high ability to induce attachment and metamorphosis of oyster larvae.

The present invention also includes such structural features:

The material components are: Portland cement, mineral admixture, crushed stone, sand, water, dark pigment, biological calcium powder and superplasticizer. The weight ratios are: 8.5%-16.0%, 3.5% %～11.0%, 39.4%～49.8%, 24.9%～37.3%, 6.2%～8.7%, 0.2%～1.7%, 0.2～1.7% and 0.02%～0.1%.

Preferably, the dark pigments are: one or both of iron oxide black, aniline black, carbon black, antimony sulfide, iron oxide red, and organic pigment red. According to the degree of influence on the performance of concrete, these pigments are For modification, one of transparent resin, organosilicon, dimethylsiloxane and superhydrophobic material is used for modification treatment.

Preferably, the biological calcium powder is a composite of bovine bone powder and biological calcium carbonate powder, including oyster shell powder, fish bone powder, egg shell powder, and coral powder, and the fineness is 100-1000 mesh.

Preferably, the biological calcium powder modification method: the oyster shell powder, egg shell powder, coral powder and fish bone powder between 100 meshes and 500 meshes are treated with the following acids, including acetic acid, acetic acid, silicic acid, sulfurous acid One or both of the following; and the 100-mesh to 500-mesh bovine bone meal is treated with the following acids, including one or both of diluted phosphoric acid, sulfuric acid, hydrochloric acid and nitric acid.

Preferably, the Portland cement is ordinary Portland cement with a strength grade of >32.5, and the mineral admixture includes one or more combinations of silica fume, slag powder and fly ash.

Preferably, the sand is one or more of river sand, machine-made sand or desalinated sea sand, and the gradation is good.

A preparation method of green concrete for inducing attachment of marine sessile organisms, comprising the following steps:

S1: Accurate weighing of Portland cement, mineral admixtures, crushed stone, sand, water, dark pigments, bio-calcium powder and superplasticizers;

S2: First put the crushed stone and sand into the concrete mixer and mix for 0.5-1 minute; then add Portland cement, mineral admixture, bio-calcium powder, dark pigment, and continue to mix for 0.5-1 minute; then add water Stir with superplasticizer for 2 to 6 minutes; after stirring evenly, pour and vibrate, and then carry out standard curing for 28 days or curing according to the actual situation, and then the dark silicic acid with good induction effect of marine sessile organisms can be obtained Salt cement concrete.

Compared with the prior art, the beneficial effects of the present invention are:

The strength and permeability of concrete are the two most important properties of concrete. The addition of different inducers to the benchmark concrete will affect the performance of the concrete. Therefore, when considering the addition of different substances to promote the attachment, metamorphosis and later growth of oyster larvae, it is necessary to control the overall strength and impact of the concrete. The permeability does not have a big impact, and then the raw materials are selected according to the compatibility of various raw materials. When the performance of the raw materials cannot meet the actual requirements, the raw materials are modified and then added to achieve the desired function.

Description of drawings

Figure 1. The mildew situation on the surface of concrete with different mix ratios of 10% bovine bone meal.

Figure 2. Different mix ratios of 10% modified bovine bone meal with a fineness greater than 200 mesh.

Fig. 3 Schematic diagram of the 200 d real sea attachment experiment.

Fig. 4 Schematic diagram of the 300 d real sea attachment experiment.

Detailed ways

The present invention will be described in detail below by means of examples, which are only used to illustrate the present invention and do not limit the scope of the present invention. Embodiments 1 to 16 are implemented in the same way, and their concrete mixing ratios are as follows:

Example 1: Ordinary Portland cement concrete mixing ratio refers to the weight proportions of ordinary Portland cement, crushed stone, sand, water and polycarboxylate superplasticizer powder: 17.1%, 46.67%, 29.0%, 7.2% %, 0.03%.

The parent rock of the crushed stone is one of basalt and diabase, its maximum particle size is not more than 50mm, and the gradation is good; the sand is river sand, machine-made sand (the parent rock is granite, basalt one) or one or more of desalinated sea sand, and the gradation is good. The water should meet the water standard for concrete (JGJ63-2006), ^Cl- content <1000mg/L, pH value>4.5, and has little effect on the difference of initial setting time and final setting time, strength and permeability of cement. And the above materials selected in Examples 1-16 are the same.

Example 2: Standard concrete mix ratio: ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate superplasticizer powder The weight ratios are: 10.26%, 0.86%, 5.98% , 46.67%, 29.0%, 7.2%, 0.03%.

The above examples show that adding blast furnace slag powder and silica fume into concrete can not only fill the gaps between particles such as cement, but also cause pozzolanic reaction, thereby improving the interface microstructure in the transition zone, which not only ensures the basic strength of concrete, but also Reduce the alkalinity and permeability of concrete itself. While reducing the alkalinity difference between concrete and its contact with seawater, its low permeability can also control the release rate of alkali, and finally make it easier for oyster larvae to attach to the concrete surface.

Example 3: The weight ratios of unmodified dark pigment, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate superplasticizer powder are: 0.51%, 10.26%, 0.79%, 5.54%, 46.67%, 29.0%, 7.2%, 0.03%.

Example 4: The weight ratios of unmodified dark pigment, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate superplasticizer powder are: 0.86%, 10.26%, 0.75%, 5.23%, 46.67%, 29.0%, 7.2%, 0.03%.

Example 5: The weight ratios of unmodified dark pigment, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate superplasticizer powder are: 1.37%, 10.26%, 0.68%, 4.79%, 46.67%, 29.0%, 7.2%, 0.03%.

Example 6: Modified dark pigments (mass ratio of iron oxide black:aniline black mixture=1:1), ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate water-reduced The weight ratio of the powder is 0.51%, 10.26%, 0.79%, 5.54%, 46.67%, 29.0%, 7.2%, 0.03%.

Example 7: Modified dark pigments (iron oxide black:aniline black mixture mass ratio=1:1), ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate water-reduced The weight ratio of the powder is 0.86%, 10.26%, 0.75%, 5.23%, 46.67%, 29.0%, 7.2%, 0.03%.

Example 8: Modified dark pigments (iron oxide black:aniline black mixture mass ratio=1:1), ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate water-reduced The weight ratio of the powder is 1.37%, 10.26%, 0.68%, 4.79%, 46.67%, 29.0%, 7.2%, 0.03%.

The modified dark pigment is made of 196 transparent resin, mixed with 3% curing agent and 1.5% accelerator, and the volume ratio of pigment to resin is: 1:0.2; curing at room temperature for 4 hours, curing at 60 °C for 4 hours, and then Crack it and grind it with a vibration mill, the fineness is more than 400 mesh.

The black pigment has a great effect on the permeability of concrete, and the oyster larvae attachment decreases with the increase of the content. On the one hand, the increase in the permeability of concrete increases the exudation of alkali in the concrete. On the other hand, the concentration of iron ions may increase due to the conversion of iron oxides into iron ions, which will inhibit the attachment of oyster larvae. In response to this problem, using resin to coat the pigment and then grinding it into powder can greatly improve the impermeability of concrete, especially when the dosage is 1.37%, the electric flux is only increased by 3.2%. At the same time, with the increase of dark pigment, the oyster attachment continued to increase, which was different from the 1.37% content before modification, which showed that the attachment rate of oyster larvae decreased.

Example 9: The weight ratios of unmodified bovine bone meal, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate superplasticizer powder are: 0.51%, 10.26%, 0.79% %, 5.54%, 46.67%, 29.0%, 7.2%, 0.03%.

Example 10: The weight ratios of unmodified bovine bone meal, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate superplasticizer powder are: 0.86%, 10.26%, 0.75% %, 5.23%, 46.67%, 29.0%, 7.2%, 0.03%.

Example 11: The weight ratios of unmodified bovine bone meal, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate superplasticizer powder are: 1.37%, 10.26%, 0.68% %, 4.79%, 46.67%, 29.0%, 7.2%, 0.03%.

Example 12: The weight ratios of modified bovine bone meal, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate superplasticizer powder are: 0.51%, 10.26%, 0.79% , 5.54%, 46.67%, 29.0%, 7.2%, 0.03%.

Example 13: The weight ratios of modified bovine bone meal, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate superplasticizer powder are: 0.86%, 10.26%, 0.75% , 5.23%, 46.67%, 29.0%, 7.2%, 0.03%.

Example 14: The weight ratios of modified bovine bone meal, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, sand, water and polycarboxylate superplasticizer powder are: 1.37%, 10.26%, 0.68% , 4.79%, 46.67%, 29.0%, 7.2%, 0.03%.

The 100-mesh bovine bone meal was added to the phosphoric acid solution with a concentration of 2%, the weight ratio of the two was 1:3, the temperature was 20 to 30 ° C, and the stirring speed was 200 to 500 rpm in a stirrer for 30 minutes. Centrifuge at 5000 rpm for 3 minutes, pour off the supernatant, and wash the solid matter of the centrifuged solid matter with water for 2 to 3 times, and the washing water no longer shows acidity; vacuum the solid matter after centrifugation at 40°C Dry, mix the dried beef bone meal and slag powder at a ratio of 1:4, and use a vibrating mill to grind to a fineness of more than 200 mesh, and set aside.

Note: Grind the modified beef bone meal fineness to 200-300 mesh

In view of the difficulty in grinding the bovine bone meal, it is generally difficult to continue grinding at about 100 mesh. Here, the 80-mesh bovine bone meal is chemically modified by using dilute phosphoric acid with a concentration of 2%, and then the dried bovine bone meal is mixed with 1 : 4 slag powder, use a vibration mill to grind to a fineness of more than 200 mesh. In this way, the modified bovine bone meal increases its contact with the alkaline substances in the concrete, and at the same time, the microstructure inside the concrete is more compact, and the mildew phenomenon that appeared before does not appear. And after the modification, the permeability of the concrete is improved in the case of low dosage. Even if the dosage reached 1.37%, its electric flux increased only 4.2%, and the attachment change rate of oyster larvae increased from 205% to 400%.

Embodiment 15: modified bovine bone meal, modified dark pigment (iron oxide black: nigrosine mixture mass ratio = 1:1), oyster shell powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, The weight ratio of sand, water and polycarboxylate superplasticizer powder is as follows: 0.51%, 0.86%, 0.51%, 10.26%, 0.62%, 4.34%, 46.67%, 29.0%, 7.2%, 0.03%.

Embodiment 16: modified bovine bone meal, modified dark pigment (iron oxide black: nigrosine mixture mass ratio = 1:1), oyster shell powder, ordinary Portland cement, silica fume, blast furnace slag powder, crushed stone, The weight ratios of sand, water and polycarboxylate superplasticizer powder are as follows: 0.86%, 0.86%, 0.51%, 10.26%, 0.58%, 4.03%, 46.67%, 29.0%, 7.2%, 0.03%.

In this example, on the basis of the benchmark concrete, the dark pigment, oyster shell powder and beef bone meal are compounded to provide the necessary Ca ²⁺ for oyster attachment and metamorphosis through the benchmark concrete, and it has a low alkalinity; at the same time, the dark pigment Make the concrete darker, absorb almost all visible light, the concrete surface becomes black, providing a dark environment; adding shell powder and bovine bone meal provides HCO ₃ ^2- , PO ₄ ^3- , and various trace amounts necessary for its adhesion Elements, together promote the attachment of oysters, so that when the dark pigment is 0.86%, the oyster shell powder is 0.51%, and the beef bone meal is 0.51%, the adhesion change rate of oyster larvae can reach 317%. When the dark pigment is 0.86%, the oyster When the shell meal was 0.51% and the bovine bone meal was 0.86%, the increase in the adhesion change rate was 517%.

The specific operation steps of the implementation methods of the embodiments 1 to 16 are as follows:

According to the above-mentioned preparation method of the dark Portland cement concrete for inducing the attachment of marine sessile organisms, three Φ100×50mm cylindrical specimens and ten 200×200×30mm cuboid specimens were prepared for testing the concrete respectively. 28d resistance to chloride ion permeability and oyster larvae attachment metamorphosis in the laboratory after 28d of standard curing. The specific operation steps are as follows:

(1) Specimen forming

1. Calculate and accurately weigh ordinary Portland cement, mineral admixture, crushed stone, sand, water, dark pigment, biological calcium powder and polycarboxylate superplasticizer powder according to the above-mentioned mass.

2. First put the crushed stone and sand into the concrete mixer and stir for 0.5 to 1 minute; then add Portland cement, mineral admixture, biological calcium powder, dark pigment, and continue to stir for 0.5 to 1 minute; then add water Stir with superplasticizer for 2 to 6 minutes; after stirring evenly, pour, vibrate and demould to obtain 3 Φ100×50mm cylindrical specimens and 5 200×200×30 mm cuboid specimens; Finally, they were put into the standard curing room for 28 days, and the corresponding permeability performance was evaluated at each instar stage, and the oyster larvae attachment and metamorphosis experiments were carried out in the laboratory after 28 days.

(2) The specific steps of the rapid chloride ion penetration experiment are as follows:

According to the standard "Standard Test Method for Electrical Indication of Concrete'sAbility to Resist Chloride Ion Penetration" (ASTM1202-2017), when the standard curing is 28d, three Φ100×50mm cylindrical specimens are taken out from the curing room respectively, and the surface The water and sundries were cleaned up, and after the surface was dry, a thin layer of epoxy resin was applied to the side of the cylindrical specimen. The test pieces were then placed in a vacuum saturator for 20 to 24 h. Then take out the test piece to clean the surface, and place it in a plexiglass mold, and after testing the tightness between the test piece and the mold, put a sodium chloride solution with a mass concentration of 3% in the molds on both sides ( The electrode is connected to the negative electrode of the power source) and a sodium hydroxide solution with a molar concentration of 0.3 mol/L (the electrode is connected to the positive electrode of the power source). Then start the experimental instrument, record the experimental data after 6h, and repeat the above operation for the last two specimens. Finally, the strength calculation is carried out according to the specification.

(3) The specific steps of the indoor oyster larvae attachment metamorphosis experiment are as follows:

After 28 days of standard curing, the 200×200×30mm cuboid specimens were taken out from the curing room respectively, and the surface water and debris were cleaned up, and then put into the test pool, and the test pool was prepared in the laboratory. The abundance of oyster larvae It is 0.85ind/ml ³ . The seawater in the pool is the Yellow Sea seawater after sand filtration, and the salinity is about 32% to 34%. After the seawater level is higher than the concrete specimen, the oxygen pipes are evenly distributed in the test pool to prepare oysters. Larvae release. After slowly stirring the oyster larvae in the bucket, the seawater containing the oyster larvae was accurately weighed using a beaker, and then evenly distributed in the test tank.

And after the initiation of the oyster adhesion induction test, the seawater in the test tank was replaced every day, and the amount of water exchange was 1/3 of the total capacity of the test tank, and a screen (≥200 mesh) was used to block the drain to prevent the unattached oyster seedlings from following. When the water was lost, the seedlings on the screen were put into the test tank again. After that, chlorella was fed regularly and quantitatively using a plastic-head dropper at 9:00 and 19:00 every day, and the attachment of oysters was observed.

After the test lasted for 30 days, the water in the test pool was drained, the specimen was taken out, and the number of oysters on the specimen surface and the survival rate were statistically recorded and analyzed.

Compared with the reference document 1 (a new type of concrete artificial reef and its preparation method CN104529286A), the difference is:

The purpose of the present invention is different from the reference document: although the reference document 1 mixes oyster shell powder in the concrete, its purpose is to utilize waste, repair and improve artificial reefs. The purpose of the present invention is to induce the attachment of sessile organisms, mainly oysters, and consider the attachment of barnacles when reinforced concrete is anti-corrosion in the tidal zone.

Compared with the reference document 2 (a bionic concrete artificial reef and its preparation method 2015CN104938384A), the difference is:

(1) The purpose in the present invention is different from the reference document 2: although the reference document 2 mixes oyster shell or oyster shell powder in the concrete, its purpose is mainly realized by the biomimeticity of the surface, collecting fish, collecting microorganisms, algae , increasing the number of microorganisms to improve the water environment, without mentioning oysters. The purpose of the present invention is to induce the attachment of sessile organisms, mainly oysters, and consider the attachment of barnacles when reinforced concrete is anti-corrosion in the tidal zone.

(2) Reference document 2 pointed out that bio-calcium carbonate powder (150-200 mesh) with a cement content of less than 10% has no obvious effect on induced adhesion. However, in the present invention, modified bovine bone meal and bio-calcium carbonate powder (fineness: 100-1000 mesh) are used in the research process, and the optimum dosage of bovine bone meal and bio-calcium carbonate powder is obtained within 10% of the cementitious material. .

(3) Through the modification of bovine bone meal and bio-calcium carbonate powder, specifically, the following acids are used to treat egg shell powder, coral powder, oyster shell powder and fish bone meal between 100 mesh and 500 mesh, including acetic acid, acetic acid, One or both of silicic acid and sulfurous acid; the following acids are used for 100-mesh to 500-mesh bovine bone meal, including one or two of diluted phosphoric acid, sulfuric acid, hydrochloric acid and nitric acid.

(4) It is difficult to inlay oyster shells on the concrete surface in the comparison document, and not every engineering surface can adopt such a method, and the feasibility is low. In the present invention, shell powder is added into the concrete to induce the adhesion of fixed organisms, and the content of the shell powder accounts for less than 10% of the mass of the cementitious material, which is not only simple in construction but also greatly increases the adhesion of oysters.

(5) In the marine environment, there have been many serious corrosion of artificial reefs in recent years, which is mainly caused by the combined action of biosulfuric acid secreted by anaerobic microorganism Thiobacillus and acidic substances secreted by other bacteria. However, the ability of calcium carbonate to resist acid corrosion is very weak. Therefore, the high content of calcium carbonate with larger fineness will cause serious acid corrosion.

Compared with Comparative Document 3 (Fan Ruiliang. Effects of substrate types on oyster attachment, growth, population establishment and reef development [D]), the differences are:

(1) For the reference document 3, 80-mesh bovine bone meal, calcium powder and gypsum powder were used, which were separately added to the concrete. The fineness of all the calcareous materials in the present invention is greater than 100 meshes, which is greater than the fineness of the materials in Comparative Document 3. It is also mixed with bovine bone meal, but mixed with one or more of biological calcium carbonate powder, such as oyster shell powder, egg shell powder, fish bone meal, and coral powder. The purpose is to give full play to their inductive ability while considering the gradation of concrete particles.

(2) Under normal temperature conditions, use a vibration mill to grind the bovine bone meal. When the fineness is greater than 80 mesh, because the bovine bone meal contains a large amount of collagen, the agglomeration is serious and the grinding cannot be continued. In the present invention, the dilute acid modification technology is adopted, and the modified biological calcium powder is obtained by compound grinding with other substances to obtain the bovine bone powder with a small particle size and a fineness of more than 200 meshes. The prepared biological calcium powder retains the original substance of the biological calcium, increases the release rate of the substance inducing the attachment of oyster larvae, and reduces the content of the biological calcium powder, thereby reducing the influence on the performance of cement concrete.

(3) Since bovine bone meal is rich in organic substances such as collagen, a large amount of these substances will cause a decrease in the strength and impermeability of concrete, especially when it exceeds 5%, if the dosage is increased, the strength of the concrete will decrease rapidly, and the resistance of the concrete will decrease. Significantly poorer permeability and mildew on the concrete surface under standard curing conditions. Figure 1 shows the mildew condition of the concrete specimen. Figure 2 shows the surface condition of the modified concrete.

It can be seen from Figure 1 that the mildew on the concrete surface is white and flocculent, covering almost the entire concrete surface; the same amount of bovine bone meal, age, and curing conditions, the concrete surface in Figure 2 has no mildew.

By controlling the use of dilute acid modification and compound grinding technology, the present invention gives full play to the inducing ability of the bovine bone meal, greatly reduces the content of the bovine bone meal, and performs anti-corrosion treatment and modification to realize the compound induction based on the bovine bone meal. It has a small dosage, hardly affects the strength and permeability of concrete, and has a strong ability to attach oyster larvae, and solves the problem of mildew in concrete. Compared with the concrete without the inducer, the number of oyster larvae attached to the concrete with the inducer increased significantly.

The comparison documents and the referenced documents show that calcium content is very important for the attachment of oyster larvae, and some current experimental results also prove that adding an appropriate amount of calcium carbonate to cement-based materials can promote the attachment and growth of oyster larvae . However, there are a lot of calcium ions in cement concrete, the pH value in the pore solution is generally greater than 12.5, and the pH value of the saturated calcium hydroxide solution is about 12 at room temperature, so the calcium ion concentration in the concrete pore solution is about 5mmol/L; The solubility of calcium is very small, only 9.5×10 ^-5 mol/L (9.5×10 ^-2 mmol/L) at 25°C. At present, it is considered that the optimal range of calcium ion concentration for inducing oyster attachment is 10-25 mmol/L. Even if oyster larvae are placed in a saturated calcium carbonate solution, there is not enough Ca ²⁺ concentration to provide suitable ion concentration for oyster attachment. Furthermore, the Ca(OH) ₂ in the cement concrete can be released quickly, while the dissolution of calcium carbonate takes a longer time. Therefore, it can be determined that the incorporation of calcium carbonate materials in concrete promotes the attachment of oyster larvae, and Ca ²⁺ does not play a dominant role. The early attachment and metamorphosis of oysters are related to HCO ₃ ^- , and the secondary shell of calcium carbonate is formed together with Ca ²⁺ during metamorphosis. After adding calcium carbonate, because calcium carbonate reacts with CO ₂ and water, it forms Ca(HCO ₃ ) ₂ and participates in the attachment, which is the fundamental mechanism to promote the attachment of oyster larvae.

There is an optimum amount of calcium carbonate in cement-based materials, which can be explained from the following three aspects:

1) For the same amount of replacement cement, with the increase of calcium carbonate content, the alkali in concrete is diluted, and the total alkalinity is decreasing, but with the increase of calcium carbonate content, the probability of calcium carbonate dissolution in concrete increases. , the HCO ₃ ^- content in its solution increases, so it promotes the attachment and metamorphosis of oysters; but when the dosage is too large, the permeability of the concrete increases sharply, and the alkali and carbonate in the concrete quickly seep out, making the negative effect of alkali Prominent, and the critical or negative effect of carbonate is beginning to show, so the amount of adhesion is reduced;

2) For the same amount of substituted aggregate, with the increase of the content, the permeability of the concrete will decrease, which will lead to the decrease of the exudation of calcium ions and OH ^- , but the infiltration rate of carbonate ions will increase first, reaching a certain level. When the concentration of oyster larvae reaches the maximum value, the oyster attachment reaches the maximum value; as the content continues to increase, the calcium ion decreases greatly, while the carbonate may also decrease. decrease in volume;

3) For the same amount of substituted mineral admixtures, the permeability also increases with the increase of the content, and due to the increase of calcium carbonate, the HCO ₃ ^{-concentration} required for oyster attachment requirements reaches a suitable range, which is expressed as The attachment of oyster larvae increased; as the content of mineral admixtures continued to increase, the content of mineral admixtures decreased, so the amount of exuded alkali increased and carbonate increased, but too much alkali and HCO ₃ ^- ions would Inhibits oyster larvae attachment.

Compared with Comparative Document 4 (Li Zhenzhen, Gong Pihai, Guan Changtao, et al. Biofouling effect of concrete artificial reefs with different cement types [J]. Advances in Fisheries Science, 2017, 38(5): 57-63.), The difference is that:

The concrete in the comparison document 4 is used to enrich marine organisms, which mainly starts from the size and diversity of the attached biomass, and the main attached organisms are various algae and so on. In the present invention, the research purpose is to induce oyster attachment, but oysters and barnacles are more resistant to alkalinity than algae, and oyster attachment and metamorphosis require a large amount of calcium ions, so the two concretes seem to be the same, but in fact There is a big difference. FIG. 3 and FIG. 4 are respectively a comparison of the biological attachment situation after the actual sea attachment experiment of the reference document 4 after about 210 days and the present invention after the actual sea attachment experiment of the present invention for 300 days.

Composite Portland cement, slag Portland cement, pozzolanic Portland cement, fly ash Portland cement and aluminate cement are used in Reference Document 4: ordinary Portland cement and mineral cement are used in the present invention. The compound admixture of admixtures can realize low alkalinity cement; among them, silica fume is a kind of mineral admixture with high activity, and the appropriate dosage has obvious effect on improving the durability of reinforced concrete in the marine environment. Low alkalinity cement with excellent strength and durability is obtained. At the same time, using the high impermeability of silica fume concrete, even if the internal alkalinity of the concrete is high, there are still a large number of oyster larvae attached, metamorphosed and grown. In addition, marine plants and sessile organisms such as oysters and barnacles have different alkali tolerance, and require different environments during the attachment period and later stages. For example, the attachment, metamorphosis and later growth of barnacles and oysters require a large amount of calcium ions.

Therefore, since this part of knowledge involves the intersection of marine sessile organisms, marine plants and marine concrete engineering disciplines, whether it is in the field of concrete and engineering or in the field of marine biology, it is impossible to obtain the concrete alkali in the present invention by comparing the document 1. A technical feature that the balance between the decrease in degree and calcium ion concentration is closely related to the attachment of marine sessile organisms.

In addition, the unique feature in the present invention and the beneficial effect it has are as follows:

Dark Pigments:

Taking advantage of the light-shielding properties of oyster eye spot larvae, dark pigments (one or two of iron oxide black, aniline black, carbon black, antimony sulfide, iron oxide red, and organic pigment red) are mixed into concrete to change the concrete. The color of the concrete becomes darker, which makes the oyster larvae think that it is a dark environment, induces the oyster larvae to reach the dark concrete surface by themselves, increases the contact probability of the larvae with the concrete surface, and realizes the increase of the induced attachment rate of the oyster larvae. Specifically:

Marine biology researchers have considered the study of the attachment of marine sessile organisms using different colored substrates in order to breed and multiply or to eliminate undesired populations, which belongs to the discipline of marine biology. It is quite different from marine concrete engineering or concrete materials discipline, which are completely two major disciplines. Through the intersection of marine sessile organisms and concrete disciplines, the induced attachment of oyster larvae using dark concrete was obtained. In the present invention, the addition of dark pigments is adopted 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 present invention takes into account that concretes of different cements have different surface colors. Therefore, the amount of dark matter is determined according to the type and amount of cement. Dark pigments can also affect the properties of concrete. The most important thing is that if the penetration rate of alkali and Ca ²⁺ in the concrete is not controlled, the released alkali will affect the attachment, metamorphosis and growth of the sessile larvae, and the content of the mixture will be larger than a certain amount. , the larval attachment decreased. In the present invention, the impermeability of concrete is designed and controlled, and the main measures are: selection of dark pigment types, control of mixing amount and modification. With the increase of the content of dark matter, the attachment of larvae firstly increased. When the content of the larvae was 0.5% to 6% of the cementitious material, the attachment of larvae was the largest, but then increased slightly or remained unchanged.

Concrete permeability:

The strength and permeability of concrete are the two most important properties of concrete. The addition of different inducers to the benchmark concrete will affect the performance of the concrete. Therefore, when considering the addition of different substances to promote the attachment, metamorphosis and later growth of oyster larvae, it is necessary to control the overall strength and impact of the concrete. The permeability does not have a big impact, and then the raw materials are selected according to the compatibility of various raw materials. When the performance of the raw materials cannot meet the actual requirements, the raw materials are modified and then added to achieve the desired function. But in fact, although the aforementioned related studies have considered the effect of calcium content on the attachment of oyster larvae, they have not considered the performance of the concrete itself, the water-cement ratio, the content of calcium and its maintenance, etc. The change of properties will change the rate of alkali and ion leakage inside the concrete. Therefore, these released alkalis and ions will have a great impact on the larvae, and may change from promoting attachment to inhibiting attachment, especially when the cement content is large, this situation will be more serious. Therefore, when an inducer is added to the concrete, it is necessary to ensure that the change of the impermeability of the concrete is within a controllable range, for example, the change does not exceed 10%. In this way, the induction effects of these can be compared, otherwise, it is impossible to evaluate the effect of single-mixing inducers or compound-spiking inducers on the induction effect of oyster larvae.

Only by grasping the optimum environment for marine sessile organisms to adhere, metamorphose and grow later, and design concrete from the height of impermeability of concrete, instead of only considering the amount of various raw materials and ignoring the The impermeability of the incoming concrete changes. Therefore, this part of knowledge also involves the intersection of marine sessile biology, chemistry and marine concrete engineering disciplines. No matter it is in the field of concrete and engineering or in the field of marine biology, it is impossible to obtain the concrete impermeability in the present invention through the existing background. The overall control of sex is closely related to the technical characteristics of inducers to promote the ability of oysters to induce attachment efficiently.

Therefore, since this part of knowledge involves the intersection of marine sessile organisms, marine plants and marine concrete engineering disciplines, whether it is in the field of concrete and engineering or in the field of marine biology, the technical personnel in the field of Incorporation of dark pigments into concrete to change color, bovine bone meal modification and grinding technology, and control of concrete permeability are technical characteristics that are closely related to concrete with high efficiency in inducing oyster adhesion and high durability. And the technical feature of the present invention that the balance between the reduction of concrete alkalinity and the calcium ion concentration and the attachment of marine sessile organisms cannot be obtained by comparing with Document 4.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions can be made in these embodiments without departing from the principle and spirit of the invention and modifications, the scope of the present invention is defined by the appended claims and their equivalents.

Claims (8)

1. a dark portland cement concrete that induces marine sessile organisms to adhere, is characterized in that: by comprising portland cement, mineral admixture, crushed stone, sand, water, dark pigment, biological calcium powder and ultra It is made of plasticizer. The weight ratio of Portland cement, mineral admixture, crushed stone, sand, water, dark pigment, biological calcium powder and superplasticizer is: 8.5%～16.0%, 3.5%～ 11.0%, 39.4%-49.8%, 24.9%-37.3%, 6.2%-8.7%, 0.2%-1.7%, 0.2-1.7% and 0.02-0.1%. 2. a kind of dark portland cement concrete that induces marine sessile organisms to adhere according to claim 1, is characterized in that: described dark pigment is iron oxide black, aniline black, carbon black, antimony sulfide, iron oxide One or both of red and organic pigment red. 3. a kind of dark Portland cement concrete that induces marine sessile organisms to adhere according to claim 2, is characterized in that: described dark pigment carries out the modification of these pigments according to the performance influence degree to concrete, One of transparent resin, organosilicon, dimethylsiloxane and superhydrophobic material is used for modification treatment. 4. a kind of dark Portland cement concrete that induces marine sessile organisms to attach according to claim 1, is characterized in that: described biological calcium powder is that bovine bone meal and biological calcium carbonate powder comprise oyster shell powder, fish bone meal , egg shell powder, coral powder in one or several compounds, its fineness is 100 mesh ~ 1000 mesh. 5. a kind of dark Portland cement concrete that induces marine sessile organisms to attach according to claim 4, is characterized in that: described biological calcium powder, to the oyster shell powder, egg shell between 100 orders to 500 orders Powder, coral meal, fish bone meal are treated with the following acids, including one or both of acetic acid, acetic acid, silicic acid, and sulfurous acid; and 100-mesh to 500-mesh bovine bone meal is treated with the following acids, including diluted phosphoric acid , one or both of sulfuric acid, hydrochloric acid and nitric acid. 6 . The dark Portland cement concrete for inducing attachment of marine sessile organisms according to claim 1 , wherein the Portland cement is ordinary Portland cement, and the strength grade is greater than 32.5. 7 . , the mineral admixture includes one or more combinations of silica fume, slag powder and fly ash. 7. the described a kind of dark Portland cement concrete that induces marine sessile organisms to attach according to claim 1, is characterized in that: described sand is a kind of in river sand, machine-made sand or desalted sea sand or several. 8. a preparation method of the dark Portland cement concrete that induces the attachment of marine sessile organisms, is characterized in that, comprises the steps: S1: Accurate weighing of Portland cement, mineral admixtures, crushed stone, sand, water, dark pigments, bio-calcium powder and superplasticizers; S2: First put the crushed stone and sand into the concrete mixer and mix for 0.5-1 minute; then add Portland cement, mineral admixture, bio-calcium powder, dark pigment, and continue to mix for 0.5-1 minute; then add water Stir with superplasticizer for 2 to 6 minutes; after stirring evenly, pour and vibrate, and then carry out standard curing for 28 days or according to the actual situation, that is, a dark color that can induce the adhesion of marine sessile organisms with good effect. Portland cement concrete.

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