A degradable mold for preparing honeycomb cellular concrete

Abstract

This invention relates to the field of ecological building materials technology, and discloses a biodegradable mold for preparing honeycomb porous concrete. The mold includes a horizontally positioned base plate and four side plates vertically surrounding the perimeter of the base plate. The upper surface of the base plate has several vertically upward-pointing cylindrical protrusions, the tops of which are flush with the tops of the side plates, arranged in a regular hexagonal honeycomb matrix. The mold is made of 100 parts of edible-grade corn starch, 20-40 parts of deionized water, and 2-8 parts of food-grade glycerin. This invention, by combining a starch-based substrate with deionized water and food-grade glycerin, improves the mold's compressive strength and ensures the precision of pore formation. The mold eliminates the need for demolding and degrades in natural soil to generate monosaccharides, providing a carbon source for the early growth of internal plants. The integrated hot-pressing structure of the base plate and protrusions eliminates seams, preventing joint leakage and deformation during vibration compaction and ensuring the interconnected porosity of the porous concrete.

Description

Technical Field

[0001] This invention relates to the field of ecological building materials technology, specifically to a biodegradable mold for preparing honeycomb porous concrete. Background Technology

[0002] Vegetated concrete is commonly used in slope protection and ecological restoration projects. It requires interconnected pores within the concrete to allow plant roots to penetrate and grow downwards. During its preparation, vegetated concrete typically requires the use of molds to cast a honeycomb-like porous structure.

[0003] Existing environmentally friendly paper or bio-based molds are prone to water absorption, swelling, softening, and even structural disintegration when in contact with concrete mixes containing large amounts of moisture. The decrease in the strength of the mold itself makes it difficult to withstand the self-weight and lateral pressure of the concrete, resulting in large deviations in the pore size and low molding accuracy of the final casting.

[0004] Meanwhile, conventional plastic or metal molds require demolding after concrete molding, increasing the construction process. Even if some molds are designed to be demolder-free, their materials have a long degradation period in the natural environment, and the degradation products are usually not directly absorbed by plants. After demolding, or in the concrete pores of conventional demolder-free components, nutrients are only provided by ordinary planting soil filled in later, lacking the readily available carbon source for early plant germination, resulting in low seed germination rates and slow early growth.

[0005] Furthermore, to create a porous structure, existing molds are typically assembled from multiple components. During concrete pouring and mechanical vibration, the joints are subjected to compression and vibration, making them prone to leakage and misalignment. Cement slurry can easily flow back into the mold's pores along the joints, causing blockages. This not only reduces the interconnected porosity of the formed planted concrete but also weakens the mechanical load-bearing capacity of the solid framework, affecting subsequent engineering applications and plant growth. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a biodegradable mold for preparing honeycomb porous concrete, which solves the problems of unstable porosity and low precision in existing plant concrete molds during the casting process, as well as the inability to provide fast-acting nutrients for early plant growth after demolding.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solution: a biodegradable mold for preparing honeycomb porous concrete, comprising a horizontally arranged bottom surface and four side surfaces vertically surrounding the perimeter of the bottom surface, wherein the upper surface of the bottom surface is provided with a plurality of vertically upward extending cylindrical protrusions, the top of the cylindrical protrusions being flush with the top of the side surfaces, and the cylindrical protrusions being arranged in a regular hexagonal honeycomb matrix; the biodegradable mold is made of raw materials comprising the following parts by weight: 100 parts of edible corn starch, 20-40 parts of deionized water, and 2-8 parts of food-grade glycerin.

[0008] By adopting the above technical solution, this invention utilizes food-grade corn starch as the main substrate, combined with deionized water and food-grade glycerin, to achieve morphological stability of the mold during concrete pouring and its degradation and nutrient provision in the natural environment. Its mechanism of action and reaction process are as follows: Thermoplastic Molding and Mechanical Reinforcement Mechanism: During the molding process, corn starch granules absorb water and swell, disrupting the original crystalline regions and undergoing a gelatinization reaction. Amylose and amylopectin molecular chains extend and rearrange. Food-grade glycerol acts as a plasticizer; its small molecule hydroxyl groups enter between the starch polymer chains, weakening the intermolecular forces, increasing the mobility of the polymer chains, and reducing material brittleness. Deionized water promotes the swelling and rupture of starch granules. After cooling and setting, a dense hydrogen bond network continuous phase structure reforms between starch molecules. This dense structure enhances the compressive strength of the mold, resulting in a low volume expansion rate when the mold encounters moisture in the concrete slurry, making it less prone to softening and disintegration, thus ensuring the molding precision of the honeycomb pores.

[0009] Biodegradation and Nutrient Supply Mechanism: After the mold is placed in the natural soil environment along with the concrete component, the starch-based substrate degrades under the influence of soil moisture and microorganisms. Soil microorganisms secrete amylase, catalyzing the breakage of glycosidic bonds in the starch macromolecules. High-molecular-weight polysaccharide polymers are gradually hydrolyzed to generate dextrin and maltose, and ultimately converted into monosaccharides such as glucose. These monosaccharides are released into the surrounding soil as an active organic carbon source, increasing the local soil organic carbon content. Glucose and small-molecule organic matter are directly absorbed and utilized by the plant roots within the pores of the vegetated concrete, meeting the carbon source requirements for seed germination and early growth, thus combining the molding of engineering components with the supply of plant nutrients.

[0010] Preferably, the diameter of the cylindrical protrusions is 5-15mm, and the center-to-center distance between adjacent cylindrical protrusions is 7.5-45mm. By setting the size and spacing of the cylindrical protrusions, it is possible to accommodate the size of common slope protection plant seeds and the space required for root development. At the same time, the reasonable center-to-center distance ensures the solid wall thickness of the concrete matrix, maintains the mechanical load-bearing capacity of the planted concrete components, and prevents the concrete structure from collapsing due to excessively dense pores.

[0011] Preferably, the center-to-center distance between adjacent cylindrical protrusions is 1.5 to 3 times the diameter of the cylindrical protrusion. By limiting the ratio of hole spacing to hole diameter, the porosity of the target planted concrete after molding is maintained within a reasonable range. A spacing ratio of less than 1.5 times will result in a thin concrete skeleton, and the compressive strength will not meet engineering standards; a spacing ratio of more than 3 times will result in excessively low porosity, failing to provide sufficient space for plant growth and aeration and water permeability.

[0012] Preferably, the moisture content of the biodegradable mold is no more than 8%. By controlling the moisture content of the mold body, mold growth can be prevented during storage and transportation. The lower moisture content limits the activity of free water inside the mold, maintains the stability of the hydrogen bond network between starch molecules, and ensures that the mold has sufficient initial stiffness and compressive strength before use.

[0013] Preferably, the bottom surface and cylindrical protrusion of the biodegradable mold are integrally formed by thermoforming. The absence of gaps between the bottom surface and the protrusion prevents leakage and misalignment at the joints caused by lateral pressure during concrete pouring and vibration. The integral molding structure maintains the airtightness of the molding cavity, preventing cement slurry from flowing back into the pores and causing blockages, thus ensuring the connectivity of the pores in the planted concrete.

[0014] This invention provides a biodegradable mold for preparing honeycomb porous concrete. It has the following beneficial effects: 1. This invention uses food-grade corn starch, deionized water, and food-grade glycerin as raw materials to prepare the mold. During the molding process, the starch gelatinizes and forms a hydrogen bond network structure after shaping, thereby improving the compressive strength of the mold. This results in a low volume expansion rate when it encounters moisture in the concrete slurry, making it less prone to softening and disintegration during the pouring process, thus ensuring the molding accuracy of the honeycomb pores in the concrete.

[0015] 2. The mold of the present invention does not need to be demolded after the concrete curing is completed. It can be directly laid in the construction area along with the component. The starch base material of the mold is degraded by microorganisms in the natural environment and hydrolyzed to produce monosaccharides such as glucose. The degradation products enter the planting soil in the pores, increasing the local soil organic carbon content and providing a carbon source for plant seed germination and early growth, thus realizing the combination of component molding and in-situ supply of plant nutrients.

[0016] 3. The bottom surface of the mold and the cylindrical protrusion of this invention adopt a hot-pressed integrated molding structure, eliminating physical splicing gaps. During concrete pouring and vibration operations, leakage and misalignment deformation at the joints caused by lateral pressure are avoided, and cement slurry backflow and blockage of pores are prevented. Combined with the limited center-to-center spacing and diameter ratio of the protrusions, it ensures that the final formed vegetation concrete has a connected porosity and bearing capacity that meet the design. Attached Figure Description

[0017] Figure 1 This is a three-dimensional schematic diagram of the biodegradable mold of the present invention; Figure 2 This is a schematic cross-sectional view of the biodegradable mold of the present invention.

[0018] Among them: 1. Side plate; 2. Cylindrical protrusion; 3. Base plate. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the preparation examples, examples, comparative examples, and test examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Preparation Examples 1-3: Preparation Example 1: This preparation example provides a biodegradable mold for preparing honeycomb porous concrete, including the following steps: Weigh out 100 parts by weight of edible corn starch, 30 parts by weight of deionized water and 5 parts by weight of food-grade glycerin according to the formula. First, mix the food-grade glycerin and deionized water evenly, then add the edible corn starch and stir at high speed for 15 minutes to obtain a homogeneous slurry. Let it stand for 8 minutes to remove air bubbles from the slurry. The mixed slurry is poured into a molding cavity preheated to 60°C and pre-pressed at room temperature for 30 seconds under a pressure of 5MPa to complete the degassing and pre-forming. The pre-compressed material is subjected to constant temperature and pressure pressing at a temperature of 120℃ and a pressure of 10MPa, with a holding time of 8min, to obtain the mold blank. The mold blank is removed and shaped using a gradient drying process. First, it is dried at 40℃ for 2 hours, then the temperature is raised to 60℃ for 4 hours, and dried until the moisture content of the blank is less than or equal to 8%, thus obtaining the mold body.

[0021] like Figure 1-2 As shown, the mold body includes a horizontally arranged base plate 3 and four side plates 1 that vertically surround the four edges of the base plate 3. The upper surface of the base plate 3 is provided with a number of vertically upward extending cylindrical protrusions 2. The top of the cylindrical protrusions 2 is flush with the top of the side plates 1. The diameter of the cylindrical protrusions 2 is 20mm. They are arranged in a regular hexagonal honeycomb matrix. The center-to-center distance between adjacent cylindrical protrusions 2 is 35mm. The designed porosity of the target planted concrete after molding is 30%.

[0022] Preparation Example 2: This preparation example provides a biodegradable mold for preparing honeycomb porous concrete, including the following steps: Weigh out 100 parts by weight of edible corn starch, 20 parts by weight of deionized water and 2 parts by weight of food-grade glycerin according to the formula. First, mix the food-grade glycerin and deionized water evenly, then add the edible corn starch and stir at high speed for 10 minutes to obtain a homogeneous slurry. Let it stand for 5 minutes to remove air bubbles from the slurry. The mixed slurry is poured into a molding cavity preheated to 50°C and pre-pressed at room temperature for 20 seconds under a pressure of 3MPa to complete the degassing and pre-forming. The pre-compressed material is subjected to constant temperature and pressure pressing at a temperature of 110℃ and a pressure of 8MPa, with a holding time of 5min, to obtain the mold blank. The mold blank is removed and shaped using a gradient drying process. It is first dried at 35℃ for 1 hour, then heated to 55℃ for 3 hours, until the moisture content of the blank is less than or equal to 8%, thus obtaining the mold body.

[0023] like Figure 1-2 As shown, the mold body includes a horizontally arranged base plate 3 and four side plates 1 that vertically surround the four edges of the base plate 3. The upper surface of the base plate 3 is provided with a number of vertically upward extending cylindrical protrusions 2. The top of the cylindrical protrusions 2 is flush with the top of the side plates 1. The diameter of the cylindrical protrusions 2 is 5mm. They are arranged in a regular hexagonal honeycomb matrix. The center-to-center distance between adjacent cylindrical protrusions 2 is 15mm. The designed porosity of the target planted concrete after molding is 20%.

[0024] Preparation Example 3: This preparation example provides a biodegradable mold for preparing honeycomb porous concrete, including the following steps: Weigh out 100 parts by weight of edible corn starch, 40 parts by weight of deionized water and 8 parts by weight of food-grade glycerin according to the formula. First, mix the food-grade glycerin and deionized water evenly, then add the edible corn starch and stir at high speed for 20 minutes to obtain a homogeneous slurry. Let it stand for 10 minutes to remove air bubbles from the slurry. The mixed slurry is poured into a molding cavity preheated to 70°C and pre-pressed at room temperature for 40 seconds under a pressure of 6MPa to complete the degassing and pre-forming. The pre-compressed material is subjected to constant temperature and pressure pressing at a temperature of 130℃ and a pressure of 12MPa, with a holding time of 10min, to obtain the mold blank. The mold blank is removed and shaped using a gradient drying process. First, it is dried at 45℃ for 3 hours, then the temperature is raised to 65℃ for 5 hours, until the moisture content of the blank is less than or equal to 8%, thus obtaining the mold body.

[0025] like Figure 1-2As shown, the mold body includes a horizontally arranged base plate 3 and four side plates 1 that vertically surround the four edges of the base plate 3. The upper surface of the base plate 3 is provided with a number of vertically upward extending cylindrical protrusions 2. The top of the cylindrical protrusions 2 is flush with the top of the side plates 1. The diameter of the cylindrical protrusions 2 is 25mm. They are arranged in a regular hexagonal honeycomb matrix. The center-to-center distance between adjacent cylindrical protrusions 2 is 37.5mm. The designed porosity of the target planted concrete after molding is 40%.

[0026] Examples 1-3: Example 1: This embodiment provides a biodegradable mold for preparing honeycomb porous concrete, including the following steps: The mold body prepared in Example 1 is placed horizontally at the casting station with the cylindrical protrusion 2 of the mold facing upwards and the mold is fixed around the perimeter with special clamps to ensure that the mold is horizontal without tilting or displacement. According to the mass ratio, weigh 100 parts of ordinary Portland cement, 300 parts of discontinuous graded crushed stone aggregate, 35 parts of deionized water, and 0.8 parts of polycarboxylate-based high-efficiency water-reducing agent, put them into a forced mixer and mix for 3 minutes to obtain a uniform planted concrete mix. The above-mentioned vegetation concrete mixture is poured evenly into the forming cavity of the mold, compacted with a plate vibrator, and then the surface is leveled. It is then cured under standard conditions for 28 days. After curing, there is no need to remove the mold. The concrete component with the mold is directly laid on the target construction area. Planting soil is filled into the through pores of the concrete and mixed grass seeds are sown. The mold gradually degrades in the natural environment, and the degradation products provide absorbable organic nutrients for the plants growing in the pores of the concrete.

[0027] Example 2: This embodiment provides a biodegradable mold for preparing honeycomb porous concrete, including the following steps: The mold body prepared in Example 2 is placed horizontally at the casting station with the cylindrical protrusion 2 of the mold facing upward and the mold is fixed around the perimeter with special clamps to ensure that the mold is horizontal without tilting or displacement. According to the mass ratio, weigh 100 parts of ordinary Portland cement, 280 parts of discontinuous graded crushed stone aggregate, 32 parts of deionized water, and 0.6 parts of polycarboxylate-based high-efficiency water-reducing agent, put them into a forced mixer and mix for 3 minutes to obtain a uniform planted concrete mix. The above-mentioned vegetation concrete mixture is poured evenly into the forming cavity of the mold, compacted with a plate vibrator, and then the surface is leveled. It is then cured under standard conditions for 28 days. After curing, there is no need to remove the mold. The concrete component with the mold is directly laid on the target construction area. Planting soil is filled into the through-holes of the concrete and mixed grass seeds are sown. The mold gradually degrades in the natural environment, and the degradation products provide absorbable organic nutrients for plants growing in the pores of the concrete.

[0028] Example 3: This embodiment provides a biodegradable mold for preparing honeycomb porous concrete, including the following steps: The mold body prepared in Example 3 is placed horizontally at the casting station with the cylindrical protrusion 2 of the mold facing upward and the mold is fixed around the perimeter with special clamps to ensure that the mold is horizontal without tilting or displacement. According to the mass ratio, weigh 100 parts of ordinary Portland cement, 320 parts of discontinuous graded crushed stone aggregate, 38 parts of deionized water, and 1.0 part of polycarboxylate-based high-efficiency water-reducing agent, put them into a forced mixer and mix for 3 minutes to obtain a uniform planted concrete mix. The above-mentioned vegetation concrete mixture is poured evenly into the forming cavity of the mold, compacted with a plate vibrator, and then the surface is leveled. It is then cured under standard conditions for 28 days. After curing, there is no need to remove the mold. The concrete component with the mold is directly laid on the target construction area. Planting soil is filled into the through-holes of the concrete and mixed grass seeds are sown. The mold gradually degrades in the natural environment, and the degradation products provide absorbable organic nutrients for plants growing in the pores of the concrete.

[0029] Comparative Examples 1-5: Comparative Example 1: Compared to Example 1, the difference lies in that a conventional ABS plastic mold with the same size and structural arrangement is used instead of the mold body prepared in Example 1; and after curing, a manual demolding operation is required to peel off the plastic mold before laying the demolded concrete component in the target construction area. Everything else is the same.

[0030] Comparative Example 2: The difference from Example 1 is that a paper mold made from recycled kraft pulp with the same dimensional structure is used instead of the mold body prepared in Example 1. All other aspects are the same.

[0031] Comparative Example 3: The difference from Example 1 is that a polylactic acid biodegradable plastic mold with the same size and structural arrangement is used instead of the mold body prepared in Example 1. All other aspects are the same.

[0032] Comparative Example 4: Compared to Example 1, the difference lies in that the mold body used is not a one-piece molded structure; its base plate 3 and cylindrical protrusion 2 are separately pressed and then assembled by adhesive. Everything else is the same.

[0033] Comparative Example 5: The difference from Example 1 is that the mold body used does not contain food-grade glycerin plasticizer in its raw material formulation (i.e., the formula consists of only 100 parts by weight of food-grade corn starch and 30 parts by weight of deionized water). Everything else is the same.

[0034] Test Example 1-2: Test Example 1: Evaluation of Basic Mold Performance and Degradation Characteristics The test subjects were the mold bodies prepared in Examples 1-3 and Comparative Examples 2 and 5.

[0035] The compressive strength was tested using a computer-controlled electronic universal testing machine. Cube specimens measuring 50mm × 50mm × 50mm were cut from each mold body and subjected to axial compression testing at a loading speed of 2mm / min. The ultimate load at failure was recorded, and the compressive strength was calculated. Five parallel specimens from each group were taken and their average value was calculated.

[0036] The initial volume and initial mass of each group of mold samples were measured. The samples were completely immersed in 20℃ deionized water and left to stand for 72 hours. After that, the samples were taken out and the surface free water was dried with filter paper. The dimensions of the samples after immersion in water were measured with vernier calipers to calculate the volume expansion rate. The macroscopic morphological integrity of the samples was observed and recorded.

[0037] After removing impurities from natural surface soil, samples were placed in a bottomless porous test chamber for natural soil environmental degradation testing. Each mold sample was initially weighed and then buried 5cm below the soil surface. During the test, the soil moisture content was controlled at 20%-25% and the ambient temperature at 20-28℃.

[0038] Samples were taken out after 30, 60 and 90 days of burial, respectively. The surface soil was washed away with deionized water, and the samples were dried at a constant temperature of 60℃ in a drying oven until constant weight. The biodegradation rate was then weighed and calculated.

[0039] Ninety days after the mold was installed, soil samples were taken from a 2cm radius around the original location of the mold, and the total organic carbon content was determined using the potassium dichromate titration method. The increase in organic carbon was calculated based on the total organic carbon content of the same batch of blank soil without the mold.

[0040] Table 1. Test data on the physical properties of the mold base and soil degradation characteristics According to the test data in Table 1, the compressive strength of Preparation Examples 1-3 was 8.12-9.06 MPa, which can withstand the stress during the pouring and vibration of the planted concrete. Corn starch granules gelatinize upon heating and water absorption, destroying the original crystalline regions, and the amylose and amylopectin molecules rearrange to form a hydrogen bond network structure. The small hydroxyl groups of food-grade glycerol added to the formulation insert into the starch polymer chains, weakening the intermolecular forces, reducing material brittleness, and increasing density. The volume expansion rate of the preparation examples after immersion in water for 72 hours was controlled within 1.35%, and the morphology remained intact. Comparative Example 5, without added glycerol, showed excessive hydrogen bond association between starch molecules, increasing material brittleness and reducing the compressive strength to 4.53 MPa. Upon contact with water, boundary cracking and powdering occurred due to internal stress concentration. Comparative Example 2, with its paper mold, relied on physical interweaving of plant fibers, lacking a continuous phase structure. After immersion in water, capillary water absorption led to structural expansion and disintegration.

[0041] Preparations 1-3 showed a low degradation rate of 4.85%-6.12% after 30 days of burial in natural soil, ensuring that the molds would not undergo excessive degradation during the 28-day standard curing period of the planted concrete, thus maintaining the stable support of the internal pore skeleton. With time, the degradation rate exceeded 94% after 90 days of burial. Starch, a natural high-molecular-weight polysaccharide polymer, is hydrolyzed by amylase secreted by microorganisms in the soil environment, breaking glycosidic bonds and degrading macromolecular starch into dextrin, maltose, and ultimately monosaccharides such as glucose. These monosaccharides are released into the soil as an active organic carbon source, increasing soil organic carbon by 11.68-12.91 g / kg. This is directly absorbed and utilized by plant roots within the pores of the planted concrete as nutrients for germination and initial growth. Comparative Example 2, with its high cellulose crystallinity and slow microbial degradation rate (87.12% after 90 days), released less soluble carbon, resulting in a soil organic carbon increase of only 4.23 g / kg, failing to provide effective nutrient support in the early stages of plant growth.

[0042] Test Example 2: Evaluation of Physical Properties and Ecological Functions of Vegetated Concrete The test subjects were the planted concrete components prepared in Examples 1-3 and Comparative Examples 1, 3, and 4.

[0043] The 28-day compressive strength of vegetation-grown concrete members was determined according to GB / T50081 standard. The interconnected porosity of the concrete members was determined using the volumetric method.

[0044] After the component is molded and demolded (or cured in the mold), a high-precision vernier caliper is used to measure the actual diameter of each honeycomb hole on the component surface, and the maximum deviation from the mold design diameter is calculated. At the same time, the number of pores that are not interconnected due to cement slurry leakage and backflow is counted, and the pore blockage rate is calculated.

[0045] The molded vegetated concrete components were placed in an outdoor test site. An equal amount of ordinary garden soil from the same batch was filled into the honeycomb-like pores of the components. Twenty seeds of a mixture of ryegrass and tall fescue were evenly sown into each pore, and the soil was covered with a 1.5cm layer. During the experiment, the components were watered regularly daily, and the ambient temperature was controlled between 15-25℃. Thirty days after sowing, the overall vegetation cover of the components was measured using a grid method.

[0046] Table 2. Test data on the molding accuracy and performance of vegetation concrete According to the test data in Table 2, the maximum deviation of the pore size of the planted concrete formed in Examples 1-3 was controlled within 1.1 mm, and the pore blockage rate was 0%. This indicates that the mold body of the present invention has excellent morphological stability and structural sealing in the concrete pouring and vibration stages. The hot-pressed integrated molding structure of the bottom surface and the cylindrical protrusion effectively resists the lateral extrusion force, ensuring the molding accuracy of the honeycomb pores. This makes the interconnected porosity of the planted concrete (20.87%-39.42%) highly consistent with the design expectation and there are no defects of grout leakage at the joints inside. In contrast, Comparative Example 4 uses a non-integrated mold, and the joints are prone to local misalignment deformation and leakage during mechanical vibration, resulting in a maximum pore size deviation of 4.5 mm. In addition, 12.4% of the pores are blocked by backflow of cement grout, which greatly reduces the interconnected porosity and overall compressive strength of the component.

[0047] Regarding the macro-ecological performance brought about by the application of the device, the vegetation coverage rate of Examples 1-3 reached over 88% after 30 days of sowing. The mold of the present invention does not require demolding and can be retained in situ with the component. Its degradation products in the natural environment improve the microenvironment of the planting soil in the pores, meeting the early-stage fast carbon source needs of plants. In contrast, the traditional ABS plastic mold of Comparative Example 1 requires a cumbersome demolding operation and has no subsequent nutrient supply function. The polylactic acid biodegradable mold of Comparative Example 3 has an excessively long degradation cycle and cannot effectively release nutrients in the early stage. The vegetation coverage rates of the two after 30 days were only 64.6% and 67.3%, respectively. The test results confirm the advantages of the device of the present invention in ensuring the accuracy of concrete molding and the synergy of in-situ degradation and energy supply.

Claims

1. A biodegradable mold for preparing honeycomb porous concrete, characterized in that, It includes a horizontally set base plate (3) and four side plates (1) that are vertically surrounded around the four edges of the base plate (3). The upper surface of the base plate (3) is provided with a number of vertically upward cylindrical protrusions (2). The top of the cylindrical protrusions (2) is flush with the top of the side plates (1). The cylindrical protrusions (2) are arranged in a regular hexagonal honeycomb matrix. The biodegradable mold is made from raw materials comprising the following parts by weight: 100 parts of food-grade corn starch; 20-40 parts deionized water; 2-8 parts of food-grade glycerin.

2. The biodegradable mold for preparing honeycomb porous concrete according to claim 1, characterized in that, The diameter of the cylindrical protrusion (2) is 5-15mm, and the center-to-center distance between adjacent cylindrical protrusions (2) is 7.5-45mm.

3. The biodegradable mold for preparing honeycomb porous concrete according to claim 1, characterized in that, The moisture content of the biodegradable mold is no more than 8%.

4. The biodegradable mold for preparing honeycomb porous concrete according to claim 1, characterized in that, The center-to-center distance between adjacent cylindrical protrusions (2) is 1.5 to 3 times the diameter of the cylindrical protrusion (2).

5. The biodegradable mold for preparing honeycomb porous concrete according to claim 1, characterized in that, The biodegradable mold is prepared by a method comprising the following steps: First, mix the food-grade glycerin and the deionized water evenly, then add the food-grade corn starch, stir to obtain a mixed slurry, and let it stand; The mixed slurry, after being allowed to stand, is poured into a preheated molding cavity and pre-pressed at room temperature. The pre-compressed material is pressed under constant temperature and pressure to obtain the mold blank; The mold blank is removed and shaped using a gradient drying process to obtain the biodegradable mold.

6. The biodegradable mold for preparing honeycomb porous concrete according to claim 5, characterized in that, The stirring is high-speed stirring, the stirring time is 10-20 minutes, and the settling time is 5-10 minutes.

7. The biodegradable mold for preparing honeycomb porous concrete according to claim 5, characterized in that, The preheating temperature of the molding cavity is 50-70℃, the pre-compression pressure is 3-6MPa, and the pre-compression time is 20-40s.

8. The biodegradable mold for preparing honeycomb porous concrete according to claim 5, characterized in that, The constant temperature and pressure pressing is performed at a temperature of 110-130℃, a pressing pressure of 8-12MPa, and a pressing time of 5-10min.

9. The biodegradable mold for preparing honeycomb porous concrete according to claim 5, characterized in that, The specific implementation method of the gradient drying process is as follows: first dry at 35-45℃ for 1-3 hours, and then raise the temperature to 55-65℃ for 3-5 hours.

10. The biodegradable mold for preparing honeycomb porous concrete according to claim 1, characterized in that, The base plate (3) of the biodegradable mold and the cylindrical protrusion (2) are integrally formed by hot pressing.

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