Wood aggregate high-strength thermal insulation mortar and application thereof

Abstract

This invention relates to the field of lightweight concrete preparation technology, specifically disclosing a high-strength thermal insulation mortar using wood aggregate and its application. The raw materials of the thermal insulation mortar include the following components: 333-780 parts by weight of cement, 345-400 parts by weight of sand, 108-150 parts by weight of modified wood aggregate, 80-95 parts by weight of heavy calcium carbonate powder, 20-30 parts by weight of filler, 3-4.5 parts by weight of fiber, 25-30 parts by weight of polymer resin powder, and 130-155 parts by weight of water. The wood aggregate modified by the process of this invention not only has higher strength but also significantly reduces water absorption, thereby improving the mechanical strength of the resulting cement-based thermal insulation mortar.

Description

Technical Field

[0001] This invention relates to the field of thermal insulation mortar preparation technology, specifically to a high-strength thermal insulation mortar with wood aggregate and its application. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Timber is a renewable, green, and environmentally friendly natural resource, widely used in various industries. This also generates a large amount of waste timber, such as discarded wooden buildings, discarded wooden furniture, wood waste from conferences and exhibitions, and discarded branches from tree pruning. my country's forest coverage rate is only two-thirds of the global average, and its per capita forest area is less than one-quarter of the world average. Therefore, the recycling of waste timber is of great significance and can help alleviate the imbalance between timber supply and demand.

[0004] In recent years, the use of waste wood as a raw material for concrete has enriched its utilization. For example, waste wood can be processed into wood fibers and added to concrete to improve its mechanical properties, while waste wood can be processed into wood aggregates and added to concrete to reduce dependence on natural sand and gravel aggregates. Furthermore, the good thermal insulation properties of wood can be added to cement-based materials to prepare insulating mortar, which can be used as an insulation layer for exterior walls, roofs, etc. However, inherent defects in wood lead to low utilization rates in concrete, even severely limiting its application. The most common problem is the low strength of wood itself, which seriously affects the strength of the prepared cement-based materials. Wood also has a high water absorption rate; its absorption of large amounts of moisture from cement-based materials results in poor flowability, increasing construction difficulty. In addition, the absorption of large amounts of moisture from cement-based materials can lead to incomplete cement hydration, causing a decrease in concrete strength. Therefore, although my country generates a large amount of waste wood resources annually, its application in concrete materials remains extremely limited, making large-scale application difficult. Therefore, overcoming the problem of waste wood degrading the performance of concrete materials has become an urgent issue to be addressed. Summary of the Invention

[0005] In view of this, the present invention provides a high-strength thermal insulation mortar with wood aggregate and its application. The wood aggregate modified by the process of the present invention has higher strength and lower water absorption, thereby improving the mechanical strength of the obtained cement thermal insulation mortar. Specifically, the technical solution of the present invention is as follows.

[0006] First, this invention discloses a high-strength thermal insulation mortar using wood aggregate, the raw materials of which include the following components: 333-780 parts by weight of cement, 345-400 parts by weight of sand, 108-150 parts by weight of modified wood aggregate, 80-95 parts by weight of heavy calcium carbonate powder, 20-30 parts by weight of filler, 3-4.5 parts by weight of fiber, 25-30 parts by weight of polymer resin powder, and 130-155 parts by weight of water. The modified wood aggregate is prepared using the following method:

[0007] (1) The wood aggregate was softened by boiling and then freeze-dried to obtain pretreated wood aggregate.

[0008] (2) The pretreated wood aggregate is immersed in ethanol solution of tetraethyl orthosilicate. After completion, the pretreated wood aggregate is taken out and dried, and then placed in water for hydrolysis to form wood aggregate precursor A.

[0009] (3) Repeat steps (1) and (2) above several times on the wood aggregate precursor A, and then immerse the obtained wood aggregate precursor A in a saturated solution of calcium hydroxide. After completion, take out the wood aggregate precursor A and cure it to obtain wood aggregate precursor B.

[0010] (4) The wood aggregate precursor B is immersed in an alcohol solution of silane coupling agent. After the immersion is completed, the wood aggregate precursor B is taken out and washed with alcohol solution. Then the wood aggregate precursor B is dried to obtain modified wood aggregate.

[0011] Furthermore, the length of the modified wood aggregate is between 6 and 10 mm, and the particle size of the sand is between 0.2 and 0.5 mm.

[0012] Furthermore, the filler includes at least one of silica fume, fly ash, quartz powder, etc.

[0013] Furthermore, the fiber includes at least one of polypropylene fiber, steel fiber, carbon fiber, etc. Optionally, the fiber has a length of 10-20 mm and a diameter of 20-50 μm. The fiber helps to improve the crack resistance and tensile strength of the thermal insulation mortar.

[0014] Furthermore, the polymer resin powder includes any one of the following: polyacrylate powder (PAE), vinyl acetate-ethylene copolymer powder (VAE), etc.

[0015] Furthermore, in step (1), the boiling time is 1.5 to 2 hours so that the wood aggregate softens and fully absorbs water. After freeze-drying, the solid ice in the pores inside the wood aggregate sublimates and is removed, thereby expanding the pores inside the wood aggregate.

[0016] Further, in step (2), the ratio of the pretreated wood aggregate to the ethanol solution of tetraethyl orthosilicate is 1g:30~50ml. Optionally, the mass fraction of tetraethyl orthosilicate in the ethanol solution is 20~35%.

[0017] Furthermore, in step (2), the impregnation time is 65~80 minutes, so that the tetraethyl orthosilicate can be fully penetrated into the pretreated wood aggregate through impregnation.

[0018] Further, in step (2), the drying temperature is 70~85℃ and the time is 20~35min, in order to remove the residual ethanol on the pretreated wood aggregate.

[0019] Further, in step (2), the ratio of the pretreated wood aggregate to water is 1g:20~30ml. Optionally, the hydrolysis time is 40~50min, during which the tetraethyl orthosilicate in the pretreated wood aggregate hydrolyzes under the action of water to form nano-sized silica, which fills the pores in the pretreated wood aggregate.

[0020] Furthermore, in step (3), steps (1) and (2) are repeated 3 to 7 times to form a denser filling of the pores of the pretreated wood aggregate.

[0021] Further, in step (3), the ratio of the wood aggregate precursor A to the saturated calcium hydroxide solution is 1g:30~40ml. Optionally, the impregnation time is 1~1.5h, through which the calcium hydroxide enters the pores of the wood aggregate precursor A, facilitating its reaction with the nano-sized silica therein.

[0022] Furthermore, in step (3), the curing temperature is 20~25℃, the relative humidity is 92~95%, and the curing time is 18~24h. During this process, calcium hydroxide and highly active nano-silica react in the pores of the wood aggregate precursor A to form hydrated calcium silicate gel, which not only fills the pores but also has a good adhesive effect, effectively improving the mechanical strength of the wood aggregate.

[0023] Further, in step (4), the alcohol solution of the silane coupling agent is composed of the silane coupling agent and an alcohol solution, wherein the mass fraction of the silane coupling agent is 17-25%. The alcohol solution includes any one of methanol, ethanol, isopropanol, etc.

[0024] Further, in step (4), the ratio of the wood aggregate precursor B to the silane coupling agent in alcohol solution is 1g:15~25ml, and the soaking time is 1.5~2h. This process allows the silane coupling agent to enter the wood aggregate precursor B, forming a hydrophobic system inside the wood aggregate precursor B.

[0025] Further, in step (4), the ratio of wood aggregate precursor B to alcohol solution during washing is 1g:10~18ml. Optionally, the washing time is 5~10min. Optionally, the alcohol solution includes any one of methanol, ethanol, isopropanol, etc. Preferably, the alcohol solution used for washing is the same as the alcohol solution of the silane coupling agent, so as to better wash out the silane coupling agent in the surface layer of wood aggregate precursor B, so that wood aggregate precursor B forms a structure with clear water on the surface and hydrophobic interior.

[0026] Furthermore, in step (4), the drying temperature is 70~85℃ and the time is 20~30min.

[0027] Secondly, this invention discloses the application of the high-strength thermal insulation mortar with wood aggregate in exterior wall insulation, ground insulation, roof insulation, etc.

[0028] Compared with the prior art, the present invention has at least the following beneficial effects:

[0029] This invention first softens wood aggregate by boiling it in water, then freeze-dries it. The volume expansion caused by ice forming in the pores of the wood aggregate during freeze-drying expands these pores, creating a pretreated wood aggregate. However, due to the abundance and small size of pores in the wood aggregate, achieving sufficient compaction is difficult, and these pores are the main reason for its high water absorption and low compressive strength. Therefore, this invention proposes using a modifier formed from tetraethyl orthosilicate and ethanol to treat the pretreated wood aggregate, allowing the tetraethyl orthosilicate to enter the pores. Then, this invention uses water to hydrolyze the tetraethyl orthosilicate in the pores, forming nano-silica that fills the pores. On one hand, this invention utilizes these nano-silica to compact the wood aggregate, reducing its water absorption. On the other hand, this invention utilizes the highly reactive nano-sized silica formed by the above-mentioned hydrolysis reaction to further treat the resulting wood aggregate precursor A with a saturated solution of calcium hydroxide. The calcium hydroxide reacts with the nano-silica in the pores of the wood aggregate to form calcium silicate gel. This gelling material not only fills the pores of the wood aggregate, but also forms a tight and strong bond with the wood aggregate due to its excellent adhesive properties. Compared to the filling achieved by granular nano-silica, the filling achieved by the gel material is more compact. Simultaneously, the adhesive effect of the gel material can significantly improve the compressive strength of the wood aggregate, thereby reducing the adverse effects of the addition of wood aggregate on the mechanical properties of the thermal insulation mortar. Furthermore, this invention also treats the wood aggregate precursor B obtained after the above-mentioned modification treatment with an alcohol solution of silane coupling agent and then washes it with alcohol, allowing the silane coupling agent to enter the wood aggregate and form a hydrophobic system, further reducing the water absorption of the wood aggregate. Simultaneously, the modified wood aggregate is structured with different internal and surface properties, facilitating better bonding with the mortar matrix after it enters the insulation mortar, preventing delamination and the resulting cracking of the hardened insulation mortar. Furthermore, the modified wood aggregate incorporates a hydrophobic system, resulting in a more impermeable insulation layer on the building surface formed by the prepared insulation mortar. Attached Figure Description

[0030] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings, wherein:

[0031] Figure 1 The image shows the effect of the medium-modified wood aggregate prepared in Example 1 below.

[0032] Figure 2The image shows the effect of the medium-insulation mortar prepared in Example 1 below.

[0033] Figure 3 SEM images of the test blocks prepared in Example 1 below. Detailed Implementation

[0034] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer.

[0035] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as those skilled in the art. The reagents and raw materials used in this invention are readily available through conventional means, and unless otherwise specified, they are used in accordance with conventional methods or product instructions. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to the methods of this invention. The preferred embodiments and materials described in this invention are for illustrative purposes only.

[0036] Example 1

[0037] A method for preparing a high-strength thermal insulation mortar using wood aggregate includes the following steps:

[0038] 1. Preparation of modified wood aggregate:

[0039] (1) The wood aggregate made from waste wood with a length distribution between 3 and 7 mm was boiled in water for 1.5 hours, and then filtered out and freeze-dried to obtain pretreated wood aggregate.

[0040] (2) Tetraethyl orthosilicate is added to anhydrous ethanol to prepare a modified solution with a mass fraction of 30%. Then, the pretreated wood aggregate is placed in the modified solution at a ratio of 1g:40ml and stirred evenly for 70min. After completion, the pretreated wood aggregate is filtered out and placed in an oven to dry at 80℃ for 30min. Then, the dried pretreated wood aggregate is added to water at a ratio of 1g:25ml and stirred evenly. After standing for 45min, the wood aggregate precursor A is obtained.

[0041] (3) Repeat steps (1) and (2) above twice for the wood aggregate precursor A. Then, mix the obtained wood aggregate precursor A with a saturated calcium hydroxide solution at a ratio of 1g:35ml, stir evenly, and soak for 1.5 hours. After completion, filter out the wood aggregate precursor A and perform curing treatment (temperature 20℃, relative humidity 95%, curing time 20h). After completion, wood aggregate precursor B is obtained.

[0042] (4) Add silane coupling agent KH550 to anhydrous ethanol to prepare an alcohol solution with a mass fraction of 22%. Then, place the wood aggregate precursor B in the alcohol solution at a ratio of 1g:20ml, stir evenly, and soak for 2 hours. After completion, filter out the wood aggregate precursor B, mix it with anhydrous ethanol at a ratio of 1g:15ml, stir and wash for 10 minutes, then filter out the wood aggregate precursor B and place it in an oven to dry at 80℃ for 25 minutes to obtain modified wood aggregate, such as... Figure 1 As shown.

[0043] 2. Prepare the following raw materials: 360 parts by weight of 42.5 silicate cement, 375 parts by weight of sand, 130 parts by weight of the modified wood aggregate prepared in this embodiment, 90 parts by weight of heavy calcium carbonate powder, 26.5 parts by weight of silica fume, 4 parts by weight of polypropylene fiber, 28 parts by weight of PAE adhesive powder, and 145 parts by weight of water. The sand has a continuous gradation between 0.2 and 0.5 mm in particle size. The heavy calcium carbonate powder has a fineness of 300 mesh, and the fiber length is between 13 and 17 mm, with a diameter between 20 and 30 μm.

[0044] 3. Place the silicate cement, sand, modified wood aggregate, heavy calcium carbonate powder, silica fume, polypropylene fiber, and PAE adhesive powder in a mixer and dry mix for 5 minutes. Then add the water and mix for 5 minutes to obtain the thermal insulation mortar. Figure 2 As shown.

[0045] (1) The water absorption rate of the modified wood aggregate prepared in this embodiment was tested according to GB / T 14684-2022 "Sand for Construction" and the result was 5.14%.

[0046] (2) According to GB / T 17671-1999 "Test Method for Strength of Cement Mortar", the thermal insulation mortar prepared in this embodiment was poured into a mold, and after molding and curing, a specimen with a size of 40mm×40mm×160mm was made (its SEM image is shown in Figure 1). Figure 3 (As shown). The compressive strength and flexural strength of the specimen at an age of 28 days were tested. The results were: compressive strength = 28.72 MPa, flexural strength = 4.54 MPa.

[0047] Example 2

[0048] A method for preparing a high-strength thermal insulation mortar using wood aggregate includes the following steps:

[0049] 1. Preparation of modified wood aggregate:

[0050] (1) The wood aggregate made from waste wood with a length distribution between 6 and 10 mm was boiled in water for 2 hours, and then filtered out and freeze-dried to obtain pretreated wood aggregate.

[0051] (2) Tetraethyl orthosilicate is added to anhydrous ethanol to prepare a modified solution with a mass fraction of 20%. Then, the pretreated wood aggregate is placed in the modified solution at a ratio of 1g:50ml and stirred evenly for 80min. After completion, the pretreated wood aggregate is filtered out and placed in an oven to dry at 85℃ for 20min. Then, the dried pretreated wood aggregate is added to water at a ratio of 1g:30ml and stirred evenly. After standing for 40min, wood aggregate precursor A is obtained.

[0052] (3) Repeat steps (1) and (2) three times for the wood aggregate precursor A. Then, mix the obtained wood aggregate precursor A with a saturated calcium hydroxide solution at a ratio of 1g:30ml, stir evenly, and soak for 1.5 hours. After completion, filter out the wood aggregate precursor A and perform curing treatment (temperature 23℃, relative humidity 93%, curing time 18h). After completion, wood aggregate precursor B is obtained.

[0053] (4) Add silane coupling agent KH570 to anhydrous methanol to prepare an alcohol solution with a mass fraction of 17%. Then, place the wood aggregate precursor B in the alcohol solution at a ratio of 1g:15ml, stir evenly, and soak for 2 hours. After completion, filter out the wood aggregate precursor B, mix it with anhydrous methanol at a ratio of 1g:18ml, stir and wash for 5 minutes, then filter out the wood aggregate precursor B and place it in an oven to dry at 85℃ for 20 minutes to obtain modified wood aggregate.

[0054] 2. Prepare the following raw materials: 332 parts by weight of 42.5 silicate cement, 375 parts by weight of sand, 108 parts by weight of the modified wood aggregate prepared in this embodiment, 80 parts by weight of heavy calcium carbonate powder, 20 parts by weight of quartz powder, 3 parts by weight of carbon fiber, 25 parts by weight of VAE adhesive powder, and 130 parts by weight of water. The sand has a continuous gradation between 0.2 and 0.5 mm in particle size. The heavy calcium carbonate powder has a fineness of 350 mesh, and the fibers have a length between 10 and 15 mm and a diameter between 30 and 50 μm.

[0055] 3. Place the silicate cement, sand, modified wood aggregate, heavy calcium carbonate powder, quartz powder, carbon fiber and VAE adhesive powder in a mixer and dry mix for 5 minutes. Then add the water and mix for 5 minutes to obtain the thermal insulation mortar.

[0056] The water absorption rate of the modified wood aggregate prepared in this embodiment and the compressive strength and flexural strength of the specimen prepared by the thermal insulation mortar in this embodiment at an age of 28 days were tested using the same method as in Example 1 above. The results were: compressive strength = 26.24 MPa, flexural strength = 4.23 MPa, and water absorption rate = 5.03%.

[0057] Example 3

[0058] A method for preparing a high-strength thermal insulation mortar using wood aggregate includes the following steps:

[0059] 1. Preparation of modified wood aggregate:

[0060] (1) The waste wood crushed into wood aggregate with a length distribution between 5 and 8 mm is boiled in water for 2 hours, and then the wood aggregate is filtered out and freeze-dried to obtain pretreated wood aggregate.

[0061] (2) Tetraethyl orthosilicate is added to anhydrous ethanol to prepare a modified solution with a mass fraction of 35%. Then, the pretreated wood aggregate is placed in the modified solution at a ratio of 1g:30ml and stirred evenly for 65min. After completion, the pretreated wood aggregate is filtered out and placed in an oven to dry at 70℃ for 35min. Then, the dried pretreated wood aggregate is added to water at a ratio of 1g:20ml and stirred evenly. After standing for 50min, the wood aggregate precursor A is obtained.

[0062] (3) Repeat steps (1) and (2) above twice for the wood aggregate precursor A. Then, mix the obtained wood aggregate precursor A with a saturated calcium hydroxide solution at a ratio of 1g:40ml, stir evenly, and soak for 1 hour. After completion, filter out the wood aggregate precursor A and perform curing treatment (temperature 25℃, relative humidity 92%, curing time 24h). After completion, wood aggregate precursor B is obtained.

[0063] (4) Add silane coupling agent KH570 to isopropanol to prepare an alcohol solution with a mass fraction of 25%. Then, place the wood aggregate precursor B in the alcohol solution at a ratio of 1g:25ml, stir evenly, and soak for 1.5 hours. After completion, filter out the wood aggregate precursor B, mix it with anhydrous methanol at a ratio of 1g:10ml, stir and wash for 10 minutes, then filter out the wood aggregate precursor B and place it in an oven to dry at 70℃ for 30 minutes to obtain modified wood aggregate.

[0064] 2. Prepare the following raw materials: 380 parts by weight of 42.5 silicate cement, 400 parts by weight of sand, 150 parts by weight of the modified wood aggregate prepared in this embodiment, 95 parts by weight of heavy calcium carbonate powder, 30 parts by weight of fly ash, 4.5 parts by weight of polypropylene fiber, 30 parts by weight of PAE adhesive powder, and 155 parts by weight of water. The sand has a continuous gradation between 0.2 and 0.5 mm in particle size. The heavy calcium carbonate powder has a fineness of 300 mesh, and the fiber has a length between 15 and 20 mm and a diameter between 30 and 50 μm.

[0065] 3. Place the silicate cement, sand, modified wood aggregate, heavy calcium carbonate powder, fly ash, polypropylene fiber and PAE adhesive powder in a mixer and dry mix for 5 minutes. Then add the water and mix for 5 minutes to obtain the thermal insulation mortar.

[0066] The water absorption rate of the modified wood aggregate prepared in this embodiment and the compressive strength and flexural strength of the specimen prepared by the thermal insulation mortar in this embodiment at an age of 28 days were tested using the same method as in Example 1 above. The results were: compressive strength = 28.06 MPa, flexural strength = 4.76 MPa, and water absorption rate = 4.91%.

[0067] Example 4

[0068] A method for preparing a high-strength thermal insulation mortar using wood aggregate includes the following steps:

[0069] 1. Prepare the following raw materials: 360 parts by weight of 42.5 silicate cement, 375 parts by weight of sand, 130 parts by weight of wood aggregate, 90 parts by weight of heavy calcium carbonate powder, 26.5 parts by weight of silica fume, 4 parts by weight of polypropylene fiber, 28 parts by weight of PAE adhesive powder, and 145 parts by weight of water. The sand has a continuous gradation between 0.2 and 0.5 mm in particle size. The wood aggregate has a length distribution between 6 and 10 mm and is made from crushed waste wood. The heavy calcium carbonate powder has a fineness of 300 mesh, and the fiber has a length between 13 and 17 mm and a diameter between 20 and 30 μm.

[0070] 2. Place the silicate cement, sand, wood aggregate, heavy calcium carbonate powder, silica fume, polypropylene fiber and PAE adhesive powder in a mixer and dry mix for 5 minutes. Then add the water and mix for 5 minutes to obtain the thermal insulation mortar.

[0071] The water absorption rate of the wood aggregate prepared in this embodiment and the compressive strength and flexural strength of the specimen prepared by the thermal insulation mortar in this embodiment at an age of 28 days were tested using the same method as in Example 1 above. The results were: compressive strength = 12.19 MPa, flexural strength = 1.64 MPa, and water absorption rate = 16.32%.

[0072] Example 5

[0073] A method for preparing high-strength thermal insulation mortar using wood aggregate, similar to Example 1 above, differs in that the modified wood aggregate is prepared using the following process:

[0074] (1) The wood aggregate made from waste wood with a length distribution between 3 and 7 mm was boiled in water for 1.5 hours, and then filtered out and freeze-dried to obtain pretreated wood aggregate.

[0075] (2) Tetraethyl orthosilicate is added to anhydrous ethanol to prepare a modified solution with a mass fraction of 30%. Then, the pretreated wood aggregate is placed in the modified solution at a ratio of 1g:40ml and stirred evenly for 70min. After completion, the pretreated wood aggregate is filtered out and placed in an oven to dry at 80℃ for 30min. Then, the dried pretreated wood aggregate is added to water at a ratio of 1g:25ml and stirred evenly. After standing for 45min, the wood aggregate precursor A is obtained.

[0076] (3) Repeat steps (1) and (2) above twice for the wood aggregate precursor A. Then, mix the obtained wood aggregate precursor A with a saturated calcium hydroxide solution at a ratio of 1g:35ml, stir evenly, and soak for 1.5 hours. After completion, filter out the wood aggregate precursor A and perform curing treatment (temperature 20℃, relative humidity 95%, curing time 20h). After completion, wood aggregate precursor B is obtained.

[0077] (4) Mix the wood aggregate precursor B with anhydrous ethanol at a ratio of 1g:15ml, stir and wash for 10min, then filter out the wood aggregate precursor B and dry it in an oven at 80℃ for 25min to obtain modified wood aggregate.

[0078] The water absorption rate of the modified wood aggregate prepared in this embodiment and the compressive strength and flexural strength of the specimen prepared by the thermal insulation mortar in this embodiment at an age of 28 days were tested using the same method as in Example 1 above. The results were: compressive strength = 21.47 MPa, flexural strength = 3.25 MPa, and water absorption rate = 9.40%.

[0079] Example 6

[0080] A method for preparing a high-strength thermal insulation mortar using wood aggregate is the same as in Example 2 above, except that step (4) of the modified wood aggregate preparation adopts the following process: Silane coupling agent KH570 is added to anhydrous methanol to prepare an alcohol solution with a mass fraction of 17%. Then, the wood aggregate precursor B is placed in the alcohol solution at a ratio of 1g:15ml, stirred evenly, and impregnated for 2 hours. After completion, the wood aggregate precursor B is filtered out and placed in an oven to dry at 85℃ for 20 minutes to obtain the modified wood aggregate.

[0081] The water absorption rate of the modified wood aggregate prepared in this embodiment and the compressive strength and flexural strength of the specimen prepared by the thermal insulation mortar in this embodiment at an age of 28 days were tested using the same method as in Example 1 above. The results were: compressive strength = 23.81 MPa, flexural strength = 3.72 MPa, and water absorption rate = 2.66%.

[0082] Example 7

[0083] A method for preparing a high-strength thermal insulation mortar with wood aggregate is the same as in Example 2 above, except that: the modified wood aggregate is prepared in step (3) using the following process: the wood aggregate precursor A is subjected to the above steps (1) and (2) three times, and then the obtained wood aggregate precursor A is cured (temperature 23℃, relative humidity 93%, curing time 18h), and wood aggregate precursor B is obtained after completion.

[0084] The water absorption rate of the modified wood aggregate prepared in this embodiment and the compressive strength and flexural strength of the specimen prepared by the thermal insulation mortar in this embodiment at an age of 28 days were tested using the same method as in Example 1 above. The results were: compressive strength = 20.14 MPa, flexural strength = 2.87 MPa, and water absorption rate = 10.93%.

[0085] Example 8

[0086] A method for preparing high-strength thermal insulation mortar using wood aggregate is the same as in Example 3 above, except that the modified wood aggregate is prepared using the following process:

[0087] (1) The waste wood crushed into wood aggregate with a length distribution between 5 and 8 mm is boiled in water for 2 hours, and then the wood aggregate is filtered out and freeze-dried to obtain pretreated wood aggregate.

[0088] (2) The pretreated wood aggregate and the saturated solution of calcium hydroxide are mixed at a ratio of 1g:40ml and stirred evenly. After soaking for 1 hour, wood aggregate precursor A is obtained. After completion, the wood aggregate precursor A is filtered out and cured (temperature 25℃, relative humidity 92%, curing time 24h) to obtain wood aggregate precursor B.

[0089] (3) Add silane coupling agent KH570 to isopropanol to prepare an alcohol solution with a mass fraction of 25%. Then, place the wood aggregate precursor B in the alcohol solution at a ratio of 1g:25ml, stir evenly, and soak for 1.5 hours. After completion, filter out the wood aggregate precursor B, mix it with anhydrous methanol at a ratio of 1g:10ml, stir and wash for 10 minutes, then filter out the wood aggregate precursor B and place it in an oven to dry at 70℃ for 30 minutes to obtain modified wood aggregate.

[0090] The water absorption rate of the modified wood aggregate prepared in this embodiment and the compressive strength and flexural strength of the specimen prepared by the thermal insulation mortar in this embodiment at an age of 28 days were tested using the same method as in Example 1 above. The results were: compressive strength = 16.51 MPa, flexural strength = 2.23 MPa, and water absorption rate = 14.08%.

[0091] Example 9

[0092] A method for preparing a high-strength thermal insulation mortar with wood aggregate is the same as in Example 3 above, except that: the modified wood aggregate is prepared in step (2) using the following process: tetraethyl orthosilicate is added to anhydrous ethanol to prepare a modified liquid with a mass fraction of 35%, and then the pretreated wood aggregate is placed in the modified liquid at a ratio of 1g:30ml and stirred evenly and then soaked for 65min. After completion, the pretreated wood aggregate is filtered out and placed in an oven to dry at 70℃ for 35min. After completion, wood aggregate precursor A is obtained.

[0093] The water absorption rate of the modified wood aggregate prepared in this embodiment and the compressive strength and flexural strength of the specimen prepared by the thermal insulation mortar in this embodiment at an age of 28 days were tested using the same method as in Example 1 above. The results were: compressive strength = 15.88 MPa, flexural strength = 2.11 MPa, and water absorption rate = 14.56%.

[0094] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-strength thermal insulation mortar using wood aggregate, characterized in that, The raw materials for this thermal insulation mortar include the following components: 333-780 parts by weight of cement, 345-400 parts by weight of sand, 108-150 parts by weight of modified wood aggregate, 80-95 parts by weight of heavy calcium carbonate powder, 20-30 parts by weight of filler, 3-4.5 parts by weight of fiber, 25-30 parts by weight of polymer resin powder, and 130-155 parts by weight of water. The modified wood aggregate is prepared using the following method: (1) The wood aggregate was softened by boiling in water and then freeze-dried to obtain pretreated wood aggregate for later use; (2) The pretreated wood aggregate is immersed in an ethanol solution of tetraethyl orthosilicate. After the immersion is completed, the pretreated wood aggregate is removed, dried, and then placed in water for hydrolysis to form wood aggregate precursor A. (3) Repeat steps (1) and (2) above several times for the wood aggregate precursor A, and then immerse the obtained wood aggregate precursor A in a saturated solution of calcium hydroxide; after completion, take out the wood aggregate precursor A for curing to obtain wood aggregate precursor B. (4) The wood aggregate precursor B is immersed in an alcohol solution of silane coupling agent. After the immersion is completed, the wood aggregate precursor B is taken out and washed with alcohol solution. Then the wood aggregate precursor B is dried to obtain modified wood aggregate.

2. The high-strength thermal insulation mortar with wood aggregate according to claim 1, characterized in that, The length of the modified wood aggregate is between 6 and 10 mm, and the particle size of the sand is between 0.2 and 0.5 mm.

3. The high-strength thermal insulation mortar with wood aggregate according to claim 1, characterized in that, The filler includes at least one of silica fume, fly ash, and quartz powder.

4. The high-strength thermal insulation mortar with wood aggregate according to claim 1, characterized in that, The fiber includes at least one of polypropylene fiber, steel fiber, and carbon fiber.

5. The high-strength thermal insulation mortar with wood aggregate according to claim 4, characterized in that, The fiber has a length of 10-20 mm and a diameter of 20-50 μm.

6. The high-strength thermal insulation mortar with wood aggregate according to claim 1, characterized in that, The polymer resin powder includes any one of: polyacrylate powder and vinyl acetate-ethylene copolymer powder.

7. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (1), the boiling time is 1.5 to 2 hours.

8. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (2), the ratio of the pretreated wood aggregate to the ethanol solution of tetraethyl orthosilicate is 1g:30~50ml.

9. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, The mass fraction of tetraethyl orthosilicate in the ethanol solution is 20-35%.

10. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (2), the soaking time is 65~80 minutes.

11. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (2), the drying temperature is 70~85℃ and the time is 20~35min.

12. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (2), the ratio of the pretreated wood aggregate to water is 1g: 20~30ml.

13. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (2), the hydrolysis time is 40~50 min.

14. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (3), steps (1) and (2) are repeated 3 to 7 times.

15. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (3), the ratio of the wood aggregate precursor A to the saturated solution of calcium hydroxide is 1g:30~40ml.

16. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (3), the soaking time is 1 to 1.5 hours.

17. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (3), the curing temperature is 20~25℃, the relative humidity is 92~95%, and the curing time is 18~24h.

18. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (4), the alcohol solution of the silane coupling agent is composed of the silane coupling agent and the alcohol solution, wherein the mass fraction of the silane coupling agent is 17~25%.

19. The high-strength thermal insulation mortar with wood aggregate according to claim 18, characterized in that, The alcoholic liquid includes any one of methanol, ethanol, and isopropanol.

20. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (4), the ratio of the wood aggregate precursor B to the silane coupling agent in alcohol solution is 1g:15~25ml, and the impregnation time is 1.5~2h.

21. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (4), the ratio of wood aggregate precursor B to alcohol solution during washing is 1g:10~18ml.

22. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, The alcohol liquid mentioned in step (4) includes any one of methanol, ethanol, and isopropanol.

23. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (4), the washing time is 5 to 10 minutes.

24. The high-strength thermal insulation mortar with wood aggregate according to any one of claims 1-6, characterized in that, In step (4), the drying temperature is 70~85℃ and the time is 20~30min.

25. The application of the high-strength thermal insulation mortar with wood aggregate as described in any one of claims 1-24 in exterior wall insulation, ground insulation, and roof insulation.

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