Corn straw brick for road slope protection and preparation method thereof

Abstract

The invention discloses a corn straw brick for road slope protection and a preparation method, and belongs to the field of building materials, the corn straw brick comprises 65-75% of corn straw, 2-5% of sodium silicate and 20-35% of a pre-gelatinized starch binder; the preparation method comprises the following steps: S1, crushing corn straws, and feeding the crushed corn straws into a mixing bin of forming equipment through a conveying belt; s2, sodium silicate and a pre-gelatinized starch binder are injected into the mixing bin according to the mixing amount requirement, and mixing is conducted; s3, after the straw particles and the binder are fully mixed, the mixture is pushed into an extrusion module to be extruded; s4, the straw particles are pushed out of the extrusion equipment after being extruded, bonded and formed; and S5, according to the required straw brick size, cutting through a saw blade to complete the preparation of the corn straw brick. The binder in the straw brick preparation process is prepared from the sodium silicate and the pregelatinized starch, and the cost of the binder is greatly reduced while the strength and stability requirements of the straw brick for the highway engineering side slope are met.

Description

Technical Field

[0001] This invention relates to a green and environmentally friendly brick, and more particularly to a corn stalk brick for highway slope protection and its preparation method. Background Technology

[0002] As a major crop, corn produces approximately 270 million tons of corn stalks annually. Although corn stalks are a very important resource and have attracted attention, their comprehensive utilization remains unsatisfactory. Because an effective industrial model for stalk utilization has not yet been established, farmers do not see the value in the stalks and mostly burn them, causing serious environmental pollution and resource waste.

[0003] In response to the concepts of green environmental protection and sustainable development, straw building materials have gradually attracted attention. Straw building materials offer excellent thermal insulation properties, resulting in buildings with good thermal insulation and significant energy-saving effects. They also possess characteristics such as earthquake resistance, fire resistance, sound insulation, and low levels of harmful volatile organic compounds. Consequently, the construction industry is increasingly moving towards low-carbon and green building practices. Currently, the main economic and technical indicators for green building development include land saving, energy saving, water saving, material saving, and environmental protection. These four aspects of green building technology—saving land and protecting the environment—all require green building materials to be achieved. Therefore, the realization of green building performance goals is inseparable from the development of green building materials, and the development of green building materials will provide a strong guarantee for the development of green buildings.

[0004] To be applicable in construction projects, most existing straw-bonded bricks are manufactured using hot-melt adhesives through extrusion molding, resulting in high strength. However, in highway slope protection, it is desirable for straw bricks to achieve early slope stabilization. Their water absorption and retention properties promote plant growth, and as the straw bricks biodegrade, they form fertilizer, further accelerating plant growth and ultimately creating a green, ecological vegetated slope. However, existing straw bricks are not easily loosened and degraded, necessitating optimization of the bonding materials. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a corn stalk brick for highway slope protection, comprising: 65% to 75% corn stalks, 2% to 5% sodium silicate, and 20% to 35% pregelatinized starch binder.

[0006] Furthermore, the moisture content of the corn stalks is <5%.

[0007] Another aspect of the present invention provides a method for preparing corn stalk bricks for highway slope protection, comprising the steps of:

[0008] S1: After the corn stalks are crushed, they enter the mixing chamber of the molding equipment via a conveyor belt;

[0009] S2: Inject sodium silicate and pregelatinized starch binder into the mixing chamber according to the required dosage, and then mix them.

[0010] S3: After the straw pellets and binder are thoroughly mixed, they are pushed into the extrusion module for extrusion;

[0011] S4: Straw pellets are extruded and bound into shape before being pushed out of the extrusion equipment;

[0012] S5: Cut the corn stalk bricks into the required dimensions using a saw blade to complete the preparation of the corn stalk bricks.

[0013] Furthermore, in step S1, the mixing chamber has a heating and drying function.

[0014] Furthermore, in step S3, the extrusion module adjusts the extrusion pressure by adjusting the tightness of the bolts, and the extrusion module can also adjust different geometric shapes.

[0015] In summary, the present invention has the following advantages over the prior art:

[0016] This invention prepares a binder for the preparation of straw bricks using sodium silicate and pregelatinized starch, which greatly reduces the cost of the binder while meeting the strength and stability requirements of straw bricks used for highway slope engineering.

[0017] The pregelatinized starch provided by this invention is a cold water-soluble product formed by breaking and recombining starch molecular chains through physical or chemical methods. It exhibits high adhesion, film-forming properties, and biodegradability. The hydroxyl groups of the pregelatinized starch form hydrogen bonds with the silanol groups in sodium silicate hydrate, increasing the bonding strength of the composite system by 30%-50%. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0019] Figure 1 This is a diagram of straw brick slope protection stacking provided by the present invention. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form may also include the plural form unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0022] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0023] This invention provides a corn stalk brick for highway slope protection, comprising: 65%–75% corn stalks, 2%–5% sodium silicate, and 20%–35% pregelatinized starch binder.

[0024] As a preferred option, the moisture content of corn stalks should be <5%.

[0025] This invention provides a corn stalk brick for highway slope protection and its preparation method, comprising the following steps:

[0026] S1: After the corn stalks are crushed, they are conveyed into the mixing chamber of the molding equipment. During this process, the mixing chamber, which has a heating and drying function, can dry the moisture in the stalks to ensure the binding effect of the corn stalk fragments.

[0027] S2: Inject sodium silicate and pregelatinized starch binder into the mixing chamber according to the dosage requirements, and set the mixing time of the mixing chamber according to the needs;

[0028] S3: After the straw pellets and binder are thoroughly mixed, they are pushed into the extrusion module for extrusion;

[0029] As a preferred option, the extrusion module adjusts the extrusion pressure by adjusting the tightness of the bolts. At the same time, the extrusion module can also be adjusted to different geometries to produce straw bricks of different specifications and sizes.

[0030] S4: After the straw pellets are compressed and bonded into shape, they are pushed out of the extrusion equipment. Workers can then cut them into finished products using a saw blade according to the required straw brick size.

[0031] The applicable conditions and scope of straw brick slope protection are as follows:

[0032] (1) Applicable to road sections with embankment slope height ≤ 10 meters and slope 1:1 to 1:1.5. Its compressive strength must be ≥ 15 MPa (according to the "Specifications for Design of Highway Subgrade" JTG D30-2015) to ensure that it does not collapse under vehicle vibration.

[0033] (2) Its permeability (permeability coefficient ≥1×10-3cm / s) makes it an ideal choice for rain gardens and sunken green spaces, which can alleviate urban flooding.

[0034] (3) Ecological slope protection bricks can adapt to water level fluctuations, and the permeable structure can reduce water erosion. For example, in riverbanks with a slope of ≤1:1.5, the porosity of the bricks is ≥20%, which can stabilize the soil and allow aquatic plants to take root.

[0035] See Figure 1 As shown, the ecological protection construction technology of straw bricks for highway slopes involves compacting and leveling the base surface of the highway slope according to the designed slope, laying a layer of planting soil containing grass seeds with a thickness of not less than 15cm from bottom to top, and then laying straw bricks formed by high-strength extrusion of corn straw particles, water, pregelatinized starch and sodium silicate binder in the order of "from left to right and from bottom to top".

[0036] This invention improves the reuse of crop straw waste, turning waste into treasure. On the other hand, straw bricks have excellent water absorption and retention properties, promoting early vegetation growth. At the same time, the nutrients formed after the biodegradation of straw bricks can also promote plant growth, ultimately forming a vegetation root system for slope protection, which has good economic and environmental benefits.

[0037] Pregelatinized starch is a cold-water-soluble product formed by breaking and recombining starch molecular chains through physical or chemical methods. It possesses high adhesion, film-forming properties, and biodegradability. When sodium silicate solution is mixed with pregelatinized starch, the starch molecules contain a large number of hydroxyl groups (-OH). These hydroxyl groups have a strong ability to form hydrogen bonds, which can form hydrogen bonds with both water molecules and silicate ions, promoting the polymerization of silicate ions and gel formation. The hydrogen bonds formed by this dual action cause the starch molecules to swell, increasing the space occupied by the starch molecules, reducing the number of free water molecules in the solution, and increasing the viscosity of the solution. This results in a 30%-50% increase in the bonding strength of the composite system.

[0038] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A cornstalk brick for highway slope protection, characterized by, The corn straw 65%~75%, sodium silicate 2%~5% and pre-gelatinized starch binder 20%~35%. The moisture content of the corn straw is less than 5%.

2. The cornstalk brick for highway slope protection according to claim 1, characterized in that, The method comprises the steps of:

3. A method for preparing corn stalk brick for highway slope protection, characterized in that, S1: after the corn straw is crushed, it is put into the mixing bin of the forming equipment through the conveyor belt; S2: according to the mixing requirement, sodium silicate and pre-gelatinized starch binder are injected into the mixing bin and mixed; S3: after the straw particles and the binder are fully mixed, they are pushed into the extrusion module for extrusion; S4: after the straw particles are extruded and bonded, they are pushed out of the extrusion equipment; S5: according to the required size of the straw brick, the corn straw brick is prepared by cutting with a saw blade. In step S1, the mixing bin has a heating and drying function.

4. The method of claim 3, wherein the corn stalk brick for highway slope protection is characterized by, In step S3, the extrusion module adjusts the extrusion force by adjusting the tightness of the bolts, and the extrusion module can also adjust different geometric forms.

5. The method of claim 3, wherein the corn stalk brick for highway slope protection is characterized by, ​

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