A method for making permeable bricks using silt

Abstract

The invention discloses a method for making permeable bricks using silt, step one: silt pretreatment; step two: small aggregate preparation: mixing the pretreated silt particles with a curing agent, stirring evenly, extruding and cutting through an extruder to make small aggregates; step three: making permeable bricks: using the prepared small aggregates as aggregates, adding high-strength cement, sand, and water-soluble epoxy resin again, adding water, stirring evenly, putting into a mold for pressing, and making permeable bricks; step four: finished product maintenance. The advantages are: the curing agent used can improve the strength and stability of the silt, so that the small aggregates and permeable bricks have higher strength and durability.

Description

Technical Field

[0001] The invention relates to a method for making permeable bricks by utilizing silt. Background Art

[0002] With the acceleration of urbanization, a large amount of silt is generated in projects such as building foundation construction, basement excavation, river dredging, and lake dredging. If these silts are not properly handled, they will not only occupy a large amount of land resources, but may also pollute the environment. At present, the main methods of silt treatment include landfill, incineration, and modification to solidified soil, but these methods all have certain limitations. Landfill will occupy a large amount of land and may pollute groundwater; incineration will produce a large amount of harmful gases, causing secondary pollution to the environment. Modification to solidified soil is currently due to uneven technology and incomplete curing modification, resulting in a large number of re-softening situations. If the curing agent is not selected reasonably, it will also cause secondary pollution to the environment.

[0003] Permeable bricks are a kind of building material with good water permeability, which are widely used in urban roads, squares and other places. However, existing permeable bricks are mainly made of sandstone, cement and other materials, which are costly and consume a lot of resources. At the same time, due to the fine particles and high viscosity of silt, direct use in the production of permeable bricks has problems such as low strength and poor water permeability.

[0004] The existing silt residue has the problem that it is impossible to make permeable bricks or make them poorly. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the existing disclosed technology, thereby designing a method for making permeable bricks using silt.

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: a method for making permeable bricks using silt,

[0007] Step 1: Sludge pretreatment: Dehydrate the sludge, crush and screen the dehydrated sludge to remove impurities and large particles to obtain sludge particles with uniform particle size;

[0008] Step 2: Preparation of small aggregates: Mix the pretreated sludge particles with the curing agent, stir evenly, and extrude and cut into segments through an extruder to make small aggregates;

[0009] Step 3: Making permeable bricks: Use the prepared small aggregate as aggregate, add high-strength cement, sand, and water-soluble epoxy resin again, add water, stir evenly, put into a mold for pressing, and make permeable bricks;

[0010] Step 4: Finished product maintenance: Maintain the prepared permeable bricks.

[0011] Furthermore, in step one, the sludge is dehydrated to reduce its moisture content to 15-25%; then, the dehydrated sludge is crushed and screened to remove impurities and large particles therein, and finely ground to obtain sludge particles with a particle size of 0.05-0.5 mm.

[0012] Furthermore, in step 2: the curing agent may be high-strength cement, lime, fly ash, or water-soluble epoxy resin.

[0013] Furthermore, step three: pigments and additives may be added during the mixing process.

[0014] Furthermore, step four: the curing method can be natural curing or steam curing.

[0015] Further, sludge pretreatment: dehydrating the sludge with a moisture content of 80% to reduce its moisture content to 20%, then crushing and screening the dehydrated sludge to remove impurities and large particles, and finely grinding to obtain sludge particles with a particle size of 0.05~0.5mm;

[0016] Preparation of small aggregates: The pretreated sludge particles are mixed with high-strength cement, lime, fly ash and water-soluble epoxy resin in a mass ratio of 80:20:2:3:0.1, and the moisture content is controlled at 12%. After being stirred evenly, they are extruded through an extruder to form small aggregates with a diameter of 3-10 mm, and the extrusion pressure is 4 MPa;

[0017] Permeable brick production: the prepared small aggregate is directly put into the mixer as aggregate, mixed with cement, sand and water-soluble epoxy resin in a mass ratio of 60:10:30:0.5, added with an appropriate amount of water, stirred evenly, put into a mold for pressing, and made into a permeable brick with a size of 200mm×100mm×60mm; the pressing pressure is 2MPa, and the pressing time is 30s;

[0018] Curing: Place the prepared permeable bricks in a curing room for natural curing for 28 days.

[0019] Further, sludge pretreatment: dehydration treatment is performed on the sludge slurry with a moisture content of 300% to reduce its moisture content to 20%; then, the dehydrated sludge is crushed and screened to remove impurities and large particles, and finely crushed to obtain sludge particles with a particle size of 0.05~0.5mm;

[0020] Preparation of small aggregate: Mix the pretreated sludge particles with cement, lime and fly ash in a mass ratio of 75:25:2:3:0.125, control the moisture content at 10%, stir evenly, and extrude through an extruder to produce small aggregates with a diameter of 3-10 mm at an extrusion pressure of 5 MPa;

[0021] Permeable brick production: the prepared small aggregate is used as aggregate, mixed with cement, sand and water-soluble epoxy resin in a mass ratio of 50:15:35:0.075, and an appropriate amount of water is added. After stirring evenly, it is put into a mold for pressing to make a permeable road panel with a size of 500mm×300mm×60mm; the pressing pressure is 3MPa, and the pressing time is 30s;

[0022] Curing: Place the prepared permeable bricks in a steam curing room for steam curing at a temperature of 80°C for 48 hours.

[0023] The advantages are: 1. The present invention first makes the silt into high-strength small aggregates, which directly have a certain initial strength, and then uses it as aggregate to make permeable bricks, solving the problem that silt residue cannot be used to make permeable bricks, realizing the resource utilization of silt, and reducing the occupation of land resources and pollution to the environment.

[0024] 2. The curing agent used can improve the strength and stability of the silt, so that the small aggregates and permeable bricks produced have higher strength and durability.

[0025] 3. The permeable bricks made by the present invention have good water permeability, can effectively alleviate the problem of urban waterlogging, and improve the ecological environment quality of the city.

[0026] Fourth, the preparation method of the present invention is simple, low-cost and easy to promote and apply. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0028] Embodiment 1 A method for making permeable bricks using sludge, sludge pretreatment: dehydrating sludge with a moisture content of 80% to reduce its moisture content to 20%, then crushing and screening the dehydrated sludge to remove impurities and large particles therein, and finely grinding to obtain sludge particles with a particle size of 0.05-0.5 mm;

[0029] Preparation of small aggregates: The pretreated sludge particles are mixed with high-strength cement, lime, fly ash and water-soluble epoxy resin in a mass ratio of 80:20:2:3:0.1, and the moisture content is controlled at 12%. After being stirred evenly, they are extruded through an extruder to form small aggregates with a diameter of 3-10 mm, and the extrusion pressure is 4 MPa;

[0030] Permeable brick production: the prepared small aggregate is directly put into the mixer as aggregate, mixed with cement, sand and water-soluble epoxy resin in a mass ratio of 60:10:30:0.5, added with an appropriate amount of water, stirred evenly, put into a mold for pressing, and made into a permeable brick with a size of 200mm×100mm×60mm; the pressing pressure is 2MPa, and the pressing time is 30s;

[0031] Curing: Place the prepared permeable bricks in a curing room for natural curing for 28 days.

[0032] After testing, the non-sintered permeable bricks prepared in Example 1 have a splitting tensile strength of 3.1 MPa and a water permeability coefficient of 4.87×10 -2 cm / s, anti-slip index 75BPN, and anti-freeze-thaw cycle parameters meet the 25d requirements.

[0033] Embodiment 2 A method for making permeable bricks using silt, silt pretreatment: dehydrating silt slurry with a moisture content of 300% to reduce its moisture content to 20%; then, crushing and screening the dehydrated silt to remove impurities and large particles therein, and finely grinding to obtain silt particles with a particle size of 0.05-0.5 mm;

[0034] Preparation of small aggregate: Mix the pretreated sludge particles with cement, lime and fly ash in a mass ratio of 75:25:2:3:0.125, control the moisture content at 10%, stir evenly, and extrude through an extruder to produce small aggregates with a diameter of 3-10 mm at an extrusion pressure of 5 MPa;

[0035] Permeable brick production: the prepared small aggregate is used as aggregate, mixed with cement, sand and water-soluble epoxy resin in a mass ratio of 50:15:35:0.075, and an appropriate amount of water is added. After stirring evenly, it is put into a mold for pressing to make a permeable road panel with a size of 500mm×300mm×60mm; the pressing pressure is 3MPa, and the pressing time is 30s;

[0036] Curing: Place the prepared permeable bricks in a steam curing room for steam curing at a temperature of 80°C for 48 hours.

[0037] The non-sintered permeable bricks prepared in Example 2 have a splitting tensile strength of 3.5 MPa and a water permeability coefficient of 3.68×10 - 2 cm / s, anti-slip index 83BPN, and anti-freeze-thaw cycle parameters meet the 25d requirements.

[0038] Embodiments 1 and 2 include sludge pretreatment equipment, small aggregate preparation equipment, permeable brick production equipment and maintenance equipment.

[0039] Sludge pretreatment equipment: including dewatering machine, crusher and screening machine, used for dewatering, crushing and screening of sludge.

[0040] Small aggregate preparation equipment: including mixers and extruders, used to mix pre-treated sludge particles with curing agents to make high-strength small aggregates.

[0041] Permeable brick production equipment: including mixers, molds and presses, which are used to mix small aggregates as aggregates with cement, sand and other materials to make permeable bricks.

[0042] Curing equipment: including a curing room and a steam generator, which are used to cure the manufactured permeable bricks.

[0043] In the sludge pretreatment process of Examples 1 and 2, appropriate dehydration methods and equipment should be selected according to the properties and moisture content of the sludge to improve dehydration efficiency and reduce costs.

[0044] During the preparation of small aggregates, the amount of curing agent and mixing time should be strictly controlled to ensure the strength and stability of the small aggregates.

[0045] During the production process of permeable bricks, appropriate molds and pressing equipment should be selected according to the size and performance requirements of the required permeable bricks, and the pressing pressure and time should be strictly controlled to ensure the quality of the permeable bricks.

[0046] During the curing process, the appropriate curing method and time should be selected according to the size and performance requirements of the permeable bricks to ensure that the strength and performance of the permeable bricks are fully improved.

[0047] A method for making permeable bricks using silt, wherein the method makes the silt into high-strength small aggregates, which are then used as aggregates to make permeable bricks, solving the problem that silt residue cannot be used to make permeable bricks. Compared with the prior art, the small aggregates do not need to be cured to high strength first, but are directly used as aggregates to participate in the pressing production of permeable bricks after being made into aggregates, thereby achieving production continuity to improve production efficiency, and also helping to reduce the amount of cementitious materials required for secondary mixing, further reducing costs, and increasing the amount of silt used.

[0048] In summary, the non-sintered permeable bricks of the present invention are tested for performance according to the GB / T 25993-2010 standard. The average splitting tensile strength is 3.1-3.5 MPa, the minimum value of a single brick is 3.1 MPa, and the linear failure load of a single brick is 291.1 N / mm. The mechanical strength of the permeable bricks of the present invention exceeds the 3.1 MPa described in the disclosed invention patent CN 107602026 B. The water permeability coefficient is 3.68×10 -2 cm / s~4.87×10 -2 cm / s, which is 2~3 times the highest grade A in GB / T 25993-2010 standard; its anti-slip index is 75BPN~83BPN; its D25 frost resistance index is that the depth of top surface defect after freezing is less than 2.8mm, the mass loss rate of single block is less than 0.5%, and the strength loss rate is less than 13%.

[0049] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for making permeable bricks using silt, characterized in that: Step 1: Sludge pretreatment: Dehydrate the sludge, crush and screen the dehydrated sludge to remove impurities and large particles to obtain sludge particles with uniform particle size; Step 2: Preparation of small aggregates: The pretreated sludge particles are mixed with high-strength cement, lime, fly ash and water-soluble epoxy resin in a mass ratio of 80:20:2:3:0.1, and the moisture content is controlled at 12%. After being stirred evenly, the mixture is extruded through an extruder to form small aggregates with a diameter of 3-10 mm at an extrusion pressure of 4 MPa. Step 3: Making permeable bricks: Use the prepared small aggregate as aggregate, add high-strength cement, sand, and water-soluble epoxy resin again, add water, stir evenly, put into a mold for pressing, and make permeable bricks; Step 4: Finished product maintenance: Maintain the prepared permeable bricks.

2. The method for making permeable bricks using silt according to claim 1, characterized in that: Step 1: Dehydrate the sludge to reduce its moisture content to 15-25%; then, crush and screen the dehydrated sludge to remove impurities and large particles, and finely grind it to obtain sludge particles with a particle size of 0.05~0.5mm.

3. The method for making permeable bricks using silt according to claim 1, characterized in that: Step 3: Add pigments and additives during the mixing process.

4. The method for making permeable bricks using silt according to claim 1, characterized in that: Step 4: The curing method is natural curing or steam curing.

5. The method for making permeable bricks using silt according to claim 1, characterized in that: Sludge pretreatment: Dehydrate the sludge with a moisture content of 80% to reduce its moisture content to 20%. Then, crush and screen the dehydrated sludge to remove impurities and large particles, and finely grind it to obtain sludge particles with a particle size of 0.05~0.5mm; Preparation of small aggregates: The pretreated sludge particles are mixed with high-strength cement, lime, fly ash and water-soluble epoxy resin in a mass ratio of 80:20:2:3:0.1, and the moisture content is controlled at 12%. After being stirred evenly, they are extruded through an extruder to form small aggregates with a diameter of 3-10 mm, and the extrusion pressure is 4 MPa; Permeable brick production: the prepared small aggregate is directly put into the mixer as aggregate, mixed with cement, sand and water-soluble epoxy resin in a mass ratio of 60:10:30:0.5, added with an appropriate amount of water, stirred evenly, put into a mold for pressing, and made into a permeable brick with a size of 200mm×100mm×60mm; the pressing pressure is 2MPa, and the pressing time is 30s; Curing: Place the prepared permeable bricks in a curing room for natural curing for 28 days.