CN115448654A - Plant-growing concrete for mangrove plant planting - Google Patents

Abstract

The invention discloses plant growing concrete for mangrove plant planting, which consists of a porous concrete outer frame and a vegetation concrete inner core. When the method is used, the mangrove plant seedlings are planted in the vegetation concrete inner cores, and then the inner cores are filled in the porous concrete outer frame, so that the mangrove plant is planted. The plant-growing concrete provided by the invention utilizes the strength and density of the porous concrete outer frame to play a role in slowing down the tide scouring of sea waves, the water and air permeability of mangrove plants can be effectively improved by the higher porosity of the outer frame, and the vegetation concrete inner core has proper strength, density and porosity, so that the plant-growing concrete not only can prevent the loss of a planting matrix and assist the mangrove plants in fixing and resisting lodging, but also can greatly improve the water and air permeability, the survival rate and the retention rate of the mangrove plants.

Description

Plant-growing concrete for mangrove plant planting

Technical Field

The invention belongs to the technical field of ocean engineering materials, and particularly relates to plant-growing concrete for mangrove plant planting.

Background

Mangrove is a woody plant community which grows in tropical and subtropical coastal intertidal zones and is subjected to periodic seawater flooding, is an important type of wetland ecosystem on the earth, and is a key object for biological diversity protection. The mangrove forest has the functions of preventing wind, eliminating wave, promoting silt, making land and purifying water quality, and is important habitat and breeding place for aquatic bird, fish, shrimp, crab and shellfish. Meanwhile, a large amount of organic carbon can be stored in the mangrove wetland deposition process, plays an important role in slowing down global warming and other climate changes, and has important ecological functions and value.

At present, the mangrove afforestation survival rate is low, the ecological value of the mangrove is damaged, and a series of ecological and economic problems of the reduction of the yield of economic organisms of the mudflat, the continuous outbreak of artificial breeding of the mudflat, the serious disaster of red tide, the sharp increase of typhoon loss, the reduction of tourism resources and the like are caused to a certain extent. Therefore, the mangrove afforestation is urgently carried out.

Mangrove plants have special requirements on the growing environment, and only grow on the tidal flat surface between the average sea level (or slightly above) and the average high tide level (or high tide level) of the return tide, and the mangrove forest is degraded, dead or difficult to naturally renew due to too high or too low flooding frequency of the tide water. The water and air permeability of the under-forest mud of the natural community of the mangrove is poor, so that the mangrove plants are easy to die due to oxygen deficiency because the air roots are buried and the water and air permeability is reduced, in particular to some mangrove plants which are not resistant to flooding; on the other hand, due to tidal scour, the planted mangrove plants are easy to fall down, seedlings and seeds of the mangrove plants are difficult to preserve, and the difficulty of recovering the artificial afforestation vegetation and recovering functions is high. Therefore, the development of new mangrove plantation modes is particularly necessary.

Disclosure of Invention

The invention aims to provide the planting concrete for mangrove plant planting, which is prepared from commonly used and easily available raw materials, can be used for planting mangrove plant seedlings on coastal beach wetlands, is simple to operate, has low production cost, and can generate good ecological benefit and social benefit.

In order to achieve the purpose, the invention adopts the following technical scheme:

a plant growing concrete for mangrove plant planting consists of a porous concrete outer frame and a vegetation concrete inner core; the outer frame of the porous concrete is composed of 1300 to 1600 parts of stones, 260 to 500 parts of cement and 70 to 150 parts of water by weight; the vegetation concrete core is composed of 100-400 parts of sea mud, 100-400 parts of sea sand, 20-60 parts of cement and 90-180 parts of water.

Furthermore, the outer diameter of the vegetation concrete inner core is adapted to the inner diameter of the porous concrete outer frame.

When the particle size of the stone is 20 to 60 mm, the using amount of the stone is 1500g, the using amount of the cement is 200 to 500g and the water cement ratio is 0.25 to 0.50, the compressive strength of the obtained porous concrete outer frame is 3.082 to 12.423 MPa, and the density is 1716 to 2027 kg/m ³ The porosity is 17.70-36.10%.

When the sand content of the sea mud is 20 to 80 percent and the cement mixing amount is 6 to 8 percent, the compressive strength of the vegetation concrete core is 0.895 to 3.343 MPa and the density is 1340 to 1717 kg/m ³ And the porosity is 23.22 to 41.45 percent.

The use steps of the plant growing concrete are as follows:

(1) Stirring and mixing the stones and the cement by a ratio of 30 s, adding water, stirring uniformly, pouring into a mold, precuring into a blank 24 h, and demolding to obtain a porous concrete outer frame;

(2) Stirring and mixing the sea mud, the sea sand and the cement by a ratio of 30 s, adding water, stirring uniformly, then pouring into a mould, implanting mangrove plant seedlings, precuring into a blank of 24 h, and then demoulding to prepare a vegetation concrete inner core with the mangrove plant seedlings;

(3) And densely filling the vegetation concrete inner core with the mangrove plant seedlings into the porous concrete outer frame to realize the planting of the mangrove plants.

The invention has the beneficial effects that:

the plant growing concrete consists of a porous concrete outer frame and a plant growing concrete inner core. The porous concrete outer frame can effectively improve the retention rate of mangrove plants, protect the planted mangrove plants from being washed by sea waves and gnawed by aquatic animals, has higher compressive strength and higher density, can play a role in slowing down the washing of sea waves and tides, and can effectively improve the water permeability and air permeability of the mangrove plants due to the high porosity of the outer frame; the vegetation concrete core has proper strength, density and porosity, can prevent the loss of a planting matrix, can assist the mangrove plants to fix and resist lodging, and can greatly improve the water and air permeability, the survival rate and the retention rate of the mangrove plants.

Drawings

FIG. 1 is an optical microscope comparison of sea mud material (left) and vegetation concrete core (right).

Fig. 2 is a diagram of a plant concrete object planted with mangrove plants.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments. It should be emphasized that the following description is merely exemplary in nature and is not intended to limit the scope of the invention or its application.

Selecting raw materials: the cement is conch PO 42.5 ordinary portland cement, water is tap water, and the sea mud is from beach sea mud under mangrove natural community forest. Unless otherwise indicated, the test methods are conventional in the art, and the concrete is prepared into a standard test block with the specification of 100 mm × 100 mm × 100 mm for performance testing, for example, according to CECS 361-2003 ecological concrete application technical Specification or JGJ51-2002 lightweight aggregate concrete technical Specification.

Example 1 preparation of outer frame of porous concrete

According to the formula shown in the table 1, stones with different particle sizes and cement are stirred and mixed in a stirrer for 30 s, water is added for stirring until the mixture is uniform, then the mixture is poured into a mold, a blank is precured for 24 h, then the mold is removed, a porous concrete outer frame is manufactured, and various properties are measured after standard curing for 28 d.

TABLE 1 influence of water cement ratio, cement mixing amount and stone particle size on the outer frame performance of porous concrete

As can be seen from Table 1, when the particle size of the pebble is 30-40 mm, the cement consumption is 300g, and the water cement ratio is 0.25-0.50 (example 1~7), the density and porosity of the outer frame of the porous concrete are changed slightly, the compressive strength tends to increase firstly and then decrease, and the compressive strength is the maximum when the water cement ratio is 0.30; when the particle size of the stone is 30-40 mm, the cement dosage is 200-500 g and the water cement ratio is 0.3 (examples 8-11), the density and the strength of the outer frame of the porous concrete both tend to increase and the porosity tends to decrease with the increase of the cement dosage; when the particle size of the stone is 20-60 mm, the cement dosage is 300g and the water cement ratio is 0.30 (examples 12-15), the density and the strength of the outer frame of the porous concrete tend to be reduced and the porosity tends to be increased along with the increase of the particle size of the stone. Therefore, when the particle size of the stones is 20 to 60 mm, the using amount of the stones is 1500g, the using amount of the cement is 200 to 500g and the water-cement ratio is 0.25 to 0.50, the strength and the density of the concrete outer frame are moderate, and the ocean wave and tide scouring can be effectively resisted; and the porosity is appropriate, the water permeability and the air permeability can be effectively improved, the planting requirements of different tide levels are met, and the comprehensive performance of the embodiment 9 is optimal.

Example 2 preparation of a Vegetation concrete core

According to the formula shown in table 2, the inner hole of the outer frame of the porous concrete is used as a mold, sea mud, sea sand and cement are stirred and mixed in a stirrer for 30 s, water is added for stirring to be uniform, then the mixture is poured into the mold, the mold is demolded after precuring to form a blank 24 h, a vegetation concrete inner core is prepared, and various performances are measured after standard curing of 28 d.

TABLE 2 influence of sand content and cement content on the performance of the vegetation concrete core

As can be seen from Table 2, when the mixing amount of the cement is the same (examples 17 to 23), the density and the compressive strength of the vegetation concrete core tend to increase and the porosity tends to decrease with the increase of the sand content; when the sand content is the same (examples 24, 20 and 25), the compressive strength of the vegetation concrete core tends to increase with the increase of the cement content, and the density and porosity change less. Therefore, when the sand content of the sea mud is 20 to 80 percent and the cement mixing amount is 6 to 8 percent, the obtained vegetation concrete core has proper strength, density and porosity, wherein the comprehensive performance of the embodiment 20 is optimal.

Example 3 microscopic comparison of pore Structure

The vegetation concrete core prepared in example 20 was magnified 40 times by an optical microscope to observe the pore structure of the vegetation concrete core and the sea mud material, and the result is shown in fig. 1. As can be seen from the figure 1, after the vegetation concrete inner core is prepared by using the sea mud as a raw material, the porosity is obviously improved, the water permeability and the air permeability of the mangrove plant can be effectively improved, and the survival rate of the mangrove plant are greatly improved.

Example 4 comparison of specific growth rates of mangrove plants

1500g of stones and 300g of cement are stirred and mixed in a stirrer for 30 s, then 90g of water is added for stirring to be uniform, then the mixture is poured into a mold, and after precuring to form a blank 24 h, the mold is removed, so that a porous concrete outer frame is prepared; according to the formula shown in the table 3, the inner hole of the outer porous concrete frame is used as a mold, sea mud, sea sand and cement are stirred and mixed in a stirrer for 30 s, water is added for stirring till the mixture is uniform, then the mixture is poured into the mold, a mangrove plant 'Kandelia candel' is selected, the 'Kandelia candel' seedlings are planted in the inner vegetation concrete cores, the mold is removed after precuring to form a blank 24 h, and then the inner cores planted with the 'Kandelia candel' seedlings are densely filled in the outer frame to obtain the plant concrete planted with the mangrove plant. The planting is carried out in a Jinjiang scientific park area Jin Jingxi of Fuzhou university in the coastal beach wetland.

TABLE 3 influence of sand content and cement content of the vegetation concrete core on the growth of mangrove plants

As can be seen from table 3, when cement is not added, the specific growth rate and survival rate of mangrove plants are low (application example 1), and it can be seen from table 2 that it is difficult to provide a water-permeable and air-permeable matrix environment due to the low compressive strength and porosity of the vegetation concrete core when cement is not used, and the planting matrix is easy to run off, making it difficult for mangrove plants to stably grow under the scouring of ocean wave and tide. When the mixing amount of the cement is the same, the specific growth rate is increased along with the increase of the sand content (application examples 2-4); when the sand content is the same, the specific growth rate is reduced along with the increase of the cement mixing amount (application examples 3 and 5-7), because the increase of the cement mixing amount can cause the pH value of the inner core to be increased, and the normal growth requirement of the mangrove plants cannot be ensured. When the sand content is 67% and the cement mixing amount is 7%, the specific growth rate of the mangrove plants can reach 0.186 cm/d, the survival rate can reach 100%, and the effect is optimal.

Example 5 mangrove plant species comparison

1500g of stones and 300g of cement are stirred and mixed in a stirrer for 30 s, then 90g of water is added for stirring to be uniform, then the mixture is poured into a mould, and demoulding is carried out after precuring to form a blank 24 h, thus obtaining a porous concrete outer frame; taking an inner hole of a porous concrete outer frame as a mold, stirring and mixing 120 g, 240 g sea sand and 27 g cement in a stirrer for 30 s, adding 77 g water, stirring uniformly, pouring into the mold, selecting a mangrove plant 'Kandelia candel', planting 'Kandelia candel' seedlings in a vegetation concrete inner core, demoulding after precuring to form a blank 24 h, and densely filling the inner core planted with the 'Kandelia l' seedlings into the outer frame to obtain the plant concrete planted with the mangrove plant. The planting concrete with mangrove plants is respectively forested in three tidal zones of the low tidal zone, the high tidal zone and the high tidal zone of the sea area of the ecological protection and restoration area of the 'blue bay' of the Quanzhou bay, and the results are shown in a table 4 by taking the direct cutting planting of the mangrove plants as comparison.

TABLE 4 influence of different tide zone planting modes on mangrove plant retention

As can be seen from Table 4, compared with the direct cutting planting of mangrove plants for forest cultivation, the adoption of the planting concrete for afforestation can effectively improve the survival rate of the mangrove plants, and particularly, the planting concrete is more obvious in medium and high tide zones.

The above description is only a preferred embodiment of the present invention, and all equivalent changes and modifications made in accordance with the claims of the present invention should be covered by the present invention.

Claims (4)

1. The plant-growing concrete for mangrove plant planting is characterized in that: the vegetation concrete consists of a porous concrete outer frame and a vegetation concrete inner core;

the porous concrete outer frame takes stones, cement and water as raw materials, and the vegetation concrete inner core takes sea mud, sea sand, cement and water as raw materials.

2. The plant-growing concrete for mangrove plant cultivation of claim 1, wherein: the usage amount of each raw material in the porous concrete outer frame is 1300 to 1600 parts by weight of stone, 260 to 500 parts by weight of cement and 70 to 150 parts by weight of water.

3. The plant-growing concrete for mangrove plant cultivation of claim 1, wherein: the usage amount of each raw material in the vegetation concrete core is 100 to 400 parts by weight of sea mud, 100 to 400 parts by weight of sea sand, 20 to 60 parts by weight of cement and 90 to 180 parts by weight of water.

4. The plant-growing concrete for mangrove plant cultivation of claim 1, wherein: the using method comprises the following steps:

(1) Stirring and mixing the stones and the cement by a ratio of 30 s, adding water, stirring uniformly, pouring into a mold, precuring into a blank 24 h, and demolding to obtain a porous concrete outer frame;

(2) Mixing the sea mud, the sea sand and the cement in proportion by stirring for 30 s, adding water, stirring uniformly, pouring into a mold, implanting mangrove plant seedlings, precuring into a blank of 24 h, and demolding to obtain a vegetation concrete inner core with the mangrove plant seedlings;

(3) And densely filling the vegetation concrete inner core with the mangrove plant seedlings into the porous concrete outer frame to realize the planting of the mangrove plants.

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