CN104692741B - A kind of stalk cellulose fiber/water cement-based composite material and preparation method thereof - Google Patents

A kind of stalk cellulose fiber/water cement-based composite material and preparation method thereof Download PDF

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CN104692741B
CN104692741B CN201510075305.3A CN201510075305A CN104692741B CN 104692741 B CN104692741 B CN 104692741B CN 201510075305 A CN201510075305 A CN 201510075305A CN 104692741 B CN104692741 B CN 104692741B
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stalk
cement
cellulose fiber
composite
fiber
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CN104692741A (en
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周祚万
谢晓丽
苟光俊
姜曼
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Southwest Jiaotong University
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Southwest Jiaotong University
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02WCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00Technologies for solid waste management
    • Y02W30/50Reuse, recycling or recovery technologies
    • Y02W30/91Use of waste materials as fillers for mortars or concrete

Abstract

The invention discloses a kind of stalk cellulose fiber/water cement-based composite material and preparation method thereof, including the one or two in 2~20 parts of stalk fibre cellulose fibers, 60~98 parts of cement and 0~20 part of silicon ash or metakaolin, the weight of water is 0.18~0.40 with the ratio of other solid weights.The cellulose fibre that the present invention is extracted using agricultural crop straw is as the enhancing phase of cement-based material, and the addition of stalk fibre cellulose fiber improves composite board anti-bending strength and bent toughness, reduce the density of product.The utilization of agricultural straw resource is advantageously implemented using the present invention, reduces stalk and stack and burn the influence to environment, be the new approach of exploitation of agricultural crop straw, while realizing the target of sustainable development of construction material.

Description

A kind of stalk cellulose fiber/water cement-based composite material and preparation method thereof
Technical field
The invention belongs to fibre modification cement-base composite material technical field, it is related to a kind of plant cellulose fiber/water mud Based composites and preparation method thereof.
Background technology
Cement-based material is to use most construction materials in the world at present, and it has, and compression strength is high and bending strength is low The characteristics of, in order to improve the bending strength of cement material, fiber turns into one of essential component of modern cement-based material.Mesh Before, steel fibre, polypropylene fibre, glass fibre and asbestos fibre etc. have been applied and must compared into as the technology of reinforcing material It is ripe, but the corrosion of reinforcing bar is still to influence the main cause of concrete structure durability, steel fibre easily occurs at crack Corrosion problem, has become an intractable old problem;The production of PP type fiber needs phenolic compound as anti-oxidant Agent, aminated compounds is as anti-ultraviolet stabilizer, and other additives are as fire retardant, production technology both not environmentally or It is uneconomical;Glass fibre has good insulating properties and antiultraviolet, anti-static electrification, but mineral wool dirt can be directly entered Lung pipe, causes breathing problem;And the price of these fibers is also relatively expensive, the cost of concrete is added.String Compared with artificial synthetic fiber, with same intensity, but cheap, and wide material sources, environment-friendly, and with can Regeneration, it is degradable the characteristics of;Especially 1970s, after the carcinogenic problem of asbestos is suggested to so that more and more Countries and regions to string strengthen cement-based material research generate keen interest.
As one kind of string, agricultural crop straw is nature very abundant natural macromolecular material, is a kind of Inexpensive, renewable, degradable natural resources, agricultural production can all produce billions of tons of agricultural crop straw every year, long Phase is not paid attention to and developed.In China, major part agricultural crop straw is abandoned or inferior fuel combustion as waste at present Burn, not only waste the biomass resource of preciousness, and severe contamination atmospheric environment.Therefore, the exploitation of agricultural crop straw It is the task of top priority, and a kind of approach had both been provided for the exploitation of stalk resource by agricultural crop straw enhancing cement-based material, The strategic choice of construction material or even economy, environment and social sustainable development is also complied with simultaneously.
Existing investigative technique shows that the hemicellulose in stalk chemical composition seriously hinders the heat evolution velocity of cement, simultaneously The strong conjunction ability that the high alkalinity environment of cement matrix can be also destroyed between each composition of string is so as to drop low-fiber intensity;Its The waxy substance that secondary stalk surface is present, is unfavorable for the gluing of stalk fibre and cement;Above reason greatly limit crops Application of the stalk in concrete base building material.In order to improve the limitation that above-mentioned reason is applied to agricultural crop straw, traditional side Method be by stalk fibre add cement matrix before, use appropriate mode to handle to promote its alkali resistant ability.It is such as molten with NaOH Liquid is handled stalk fibre, the purpose is to destroy the wax coat on stalk surface, while being caused by dipping by lye in fiber There are a large amount of extract Precipitations of slow setting or anticoagulation to cement, so that the interfacial adhesion of reinforcing fiber and cement matrix Power, improves mechanical property (Fan Hua, the performance test research of Sheng jasmine straw fiber cement sills, Anhui agriculture of cement-based material Industry college journal 2011;38:643-646.).Above measure can increase itself and cement matrix by destroying fiber surface structure Between cohesive force, so as to improve the anti-bending strength of composite, but changing for fiber self-strength to a certain extent It is apt to without too big effect.Compared with above technology, stalk fibre cellulose fiber has following as the reinforcing material of cement matrix Advantage.First, consider from the strength characteristics of fiber itself, cellulose fibre has higher intensity compared with stalk fibre former state With bullet mould.(A.K.Bledzki, J.Gassan.Composites reinforced with cellulose according to the literature based fibres.Prog.Polym.Sci.1999;24:221-274), the elastic modelling quantity of certain string former state is 10GPa, And thus its elastic modelling quantity of the cellulose fibre of string extraction can reach more than 40GPa.Secondly, with regard to fine in composite For dimension and the interfacial effect of cement, cellulose fibre and the cement of single structure have more preferable interfacial structure adjustability, so that Be conducive to improving the cohesive force between component.3rd, the addition of stalk fibre cellulose fiber can avoid hemicellulose in stalk stock blend Fibre structure is destroyed caused by the composition such as element and lignin is degraded in cement matrix, influences the strength of materials.
The disclosed crop branch fiber elements that are used for of Chinese patent CN102230284A (ZL 201110116073.3) are extracted Ultrasonic assistant steam explosion pretreating process, and patent CN101798769A (ZL 201010141040.X) report lignin Environmental protection abstraction technique, it is proposed that a set of technology extracted for crop branch fiber element, effectively removes farming The composition of the complex structures such as hemicellulose and lignin in thing stalk, less stable, the stalk obtained through this technology Cellulose has the intensity and toughness far above former stalk fibre.
The content of the invention
In view of stalk strengthens the defect present in cement-base composite material in the prior art, the present invention is extracted using stalk Cellulose fibre is as the reinforcing material of cement-based material there is provided one kind by stalk cellulose fiber reinforced cement-based composite material Formula, technique and preparation method.It is intended to increase the anti-bending strength and toughness of cement-based material using stalk fibre cellulose fiber, and For plant cellulose fibrous absorbent it is strong the characteristics of by vacuum filtration be dehydrated and pressurize etc. a kind of low-density of technique productions, High tenacity, high-strength composite-stalk cellulose fiber cement composites.
The purpose of the present invention is realized by following means.
Present disclosure is:Stalk cellulose fiber/water cement-based composite material, by stalk fibre cellulose fiber, gelling material Material, admixture and water mixing composition.The composite is made up of the component of following part by weight:2~20 parts of stalk fibre Cellulose fiber (preferably 8~16 parts), 60~98 parts of binder materials (preferably 69~87 parts) and 0~20 part of admixture (preferably 5~ 15 parts), the weight of water is 0.16~0.40 (preferably 0.20~0.38) with the ratio of other solid weights.
In present disclosure, the stalk fibre cellulose fiber can be rice straw, wheat stalk or crops straw Any one in stalk extracts gained.
In present disclosure, the main composition and weight percent of the stalk fibre cellulose fiber are alpha cellulose Content > 85%, the length of stalk fibre cellulose fiber is 0.5~1.5mm, degree of polymerization > 400.
In present disclosure, the binder materials can be any in portland cement or Portland cement It is a kind of.
In present disclosure, the admixture is the one or two in metakaolin or silicon ash.
The preparation method of stalk cellulose fiber/water cement-based composite material of the present invention is to be achieved by the steps of 's.
Step one, 2~6min is stirred after the stalk fibre cellulose fiber after crushing adds water in beater;Then sequentially add Binder materials and admixture, 2~5min of stirring (solid content is 10~25%);
Step 2, the slurry stirred is quickly poured into the mould of certain size and taken out in 0.05~0.09MPa vacuum Suction filtration solidifies to sample surfaces under filtering pressure power;
Step 3, by the sample obtained by step 3 under 2.5~3.5MPa pressure 3~8min of pressurize, obtain product;
Step 4, after product is sealed in polybag and placed 1~2 day at ambient temperature, enters rower and supports, can also enter Water-filling is supported or steam curing.
In the present invention, in string hemicellulose, starch and other extracts are in the alkaline environment of cement Strong anticoagulation can be produced to cement.And for annual stalk fibre, it contains for the Inhibitory component of cement Amount is higher than perennial plant several times to more than ten times, greatly limit application of the stalk in cement-based material.It will be extracted in stalk The cellulose fibre gone out be applied to cement-base composite material, one be based on fiber intensity itself improve and itself and cement matrix it Between cohesive force improve double action:When composite is by certain stress, cellulose fibre removes the bonding of cement, Extract and rubbed mutually from matrix simultaneously, this surface that increased by unsticking can work done, extraction work(and frictional work Destruction work(is all improved, helps to improve the destruction of composite, and then greatly improve the intensity and toughness of composite. Furthermore, cellulose can avoid causing the intensity of composite because stalk structure is destroyed as the reinforcing agent of cement matrix Decline.Meanwhile, the different parts of different types of stalk fibre or same fiber are added after cement matrix, can cause composite The fluctuation of performance, so as to cause the uncertainty of technological parameter in actual industrial production.This be due in fiber hemicellulose and Caused by the components such as lignin, above component has very big difference with the difference of floristics and growing environment.And all plants The structure of cellulose is identical in fiber, therefore cellulose fibre is as reinforcing agent, for composite property and production work Skill has more preferable stability.
The preparation technology of stalk cellulose fiber/water cement-based composite material, first by dried stalk fibre cellulose fiber Mechanical crushing is carried out, continues stirring after adding water in beater.When cellulose fibre is uniformly dispersed, adds cement and other are mixed Close material to continue to stir, in order to ensure the dispersed of fiber, solid content does corresponding adjustment with the volume of fiber.Finally by taking out Unnecessary moisture is removed in filter dehydration, and pressurizes so that fiber has more preferable interfacial effect with cement matrix.Above composite Preparation technology is simple, easily operation so that this yield of agricultural crop straw is huge, and lacks the resource of utilization ways and obtain effectively Utilize.
The features of the present invention and beneficial effect are:
(1) enhancing phase of the present invention using stalk fibre cellulose fiber as cement-based material, the addition of stalk fibre cellulose fiber Anti-bending strength, bent toughness and the amount of deflection of composite are improved, the density of product is reduced.Finished product unit weight prepared by the present invention For 1.15~1.49g/cm3, 9.2~13.8MPa of bending strength, 62.8~3153.6J/m of bent toughness2, maximum deflection amount of deflection 2.8~11.8mm.Compared with cement paste, composite material toughness maximum can increase by more than 50 times, and unit weight is only net slurry unit weight 57.2~74.1%.Therefore, in the case where agricultural crop straw also lacks effective utilization technology, the present invention is to realize that stalk is provided Source recycles and improved a kind of effective way of ecological environment.
(2) using enhancing phase of the stalk fibre cellulose fiber as composite, its intensity and the more former straw of toughness in the present invention Stalk fiber is greatly improved, and the addition of stalk fibre cellulose fiber can avoid stalk strong caused by structure destruction in alkaline environment Degree declines;Eliminate the strong anticoagulation that hemicellulose and other extracts in stalk fibre are produced to cement;Solve stalk The problem of wax epidermis is combined difference with cement matrix.
(3) present invention in admixture silicon ash and metakaolin active component SiO2And A12O3·2SiO2, can be with cement Hydrated product Ca (OH)2Generation secondary reaction of hydration, generates the products such as drated calcium aluminate, C-S-H gels, reduces the alkali of matrix Degree, improves the intensity and toughness of material;And product only needs to that secondary water can just occur under normal pressure, normal temperature or medium temperature condition Change reaction, reduce the energy consumption of production.
Brief description of the drawings
Fig. 1 is the cellulose fibre used by the embodiment of the present invention.
Fig. 2 is the SEM figures of composite of the present invention sample section after anti-bending strength test.
Fig. 3 is not mix fiber and mix the amount of deflection figure of a certain amount of stalk cellulose fiber cement-based material.
Embodiment
Example given below is intended being further explained the present invention explanation, but is not to be construed as to present invention protection The limitation of scope, some nonessential improvement that person skilled in art makes according to the content of the invention described above to the present invention And adjustment, still fall within protection scope of the present invention.
The preparation technology of the present invention, comprises the following steps:
Step one, 2~6min is stirred after the stalk fibre cellulose fiber after crushing adds water in beater;Then sequentially add Binder materials and admixture, 2~5min of stirring (solid content is 10~25%);
Step 2, the slurry stirred is quickly poured into the mould of certain size and taken out in 0.05~0.09MPa vacuum Suction filtration solidifies to sample surfaces under filtering pressure power;
Step 3, by the sample obtained by step 3 under 2.5~3.5MPa pressure 3~8min of pressurize, obtain product.
Step 4, after product is sealed in polybag and placed 1~2 day at ambient temperature, enters rower and supports, can also enter Water-filling is supported or steam curing.
In following embodiment 1~11, cellulose fibre used is rice straw cellulose fibre.Dry paddy rice straw Stalk fiber cellulose fiber is crushed to particle diameter for 20~120 mesh in Universalpulverizer, adds water and 2~6min of stirring in beater Afterwards, binder materials and admixture are added and stir 2~5min (agitator speed in 1000~1500r/min, solid content 10~ 25%).Then the slurry stirred is quickly poured into the mould of certain size while stirring, in the true of 0.05~0.09MPa Suction filtration solidifies to sample surfaces under empty suction filtration pressure, and the pressurize 5min under 3.2MPa pressure, that is, obtains product.After shaping Product is sealed in polybag to be placed after 2 days at ambient temperature, and standard curing was by 28 days.
In order to further contrast the effect of the present invention, with embodiment of the present invention identical preparation process condition, not mixing The cement slurry of any fiber, undressed rice straw fiber/water cement-based composite material, and by prior art through alkali soluble Stalk fibre/cement-base composite material of liquid processing by as a comparison, and compare the bending strength of product, it is toughness, maximum curved Degree of deflecting and density, the results are shown in Table 1.
Fig. 1 is the SEM figures of rice fibers cellulose fiber.Fig. 2 is the SEM figures of sample section after the test of the anti-bending strength of embodiment 2. The figure 2 shows that cellulose fibre is uniformly dispersed in cement matrix, and the cohesive force having had, and most of fiber is in base It is in extraction state rather than fracture in material.
Fig. 3 is embodiment 1,3,5 and figure of the bending load of comparative example 1 to sag.The admixture of figure shows fiber and Improvement of the increase of volume to composite material toughness is notable, and significantly increases the amount of deflection of composite.
Table 1
In above-described embodiment and comparative example:The binder materials is 42.5 Portland cements.
In above-described embodiment 1~11:The main composition and weight percent of the rice fibers cellulose fiber are that first kind is fine Cellulose content > 85% is tieed up, the length of rice fibers cellulose fiber is 0.5~1.5mm, degree of polymerization > 400.
In above-mentioned comparative example 1:The product is the cement paste for not mixing any fiber.
In above-mentioned comparative example 2:The fiber is undressed rice straw fiber.
In above-mentioned comparative example 3:The fiber is the rice straw fiber after alkaline solution treatment.
In above-described embodiment and this specification, the percentage being not known is weight percent, and (or weight percent contains Amount), specific statement the step of and the equivalent prior art of process.
It can implement the invention is not restricted to above-described embodiment, described in present invention and with the good result.

Claims (1)

1. a kind of stalk cellulose fiber/water cement-based composite material, it is characterized in that, the composite is by following part by weight Component is constituted:8~16 parts of stalk fibre cellulose fiber, 69~87 parts of binder materials and 5~15 parts of admixtures, the weight of water with The ratio of other solid weights is 0.20~0.38;During the binder materials is portland cement or Portland cement Any one;The admixture is the one or two in metakaolin or silicon ash;The stalk fibre cellulose fiber is paddy rice Any one in stalk, wheat stalk or other annual crops stalks extracts gained;The stalk fibre cellulose fiber Main composition and weight percent be content of alphacellulose > 85%, the length of stalk fibre cellulose fiber for 0.5~ 1.5mm, degree of polymerization > 400;Its preparation method is:Step one, after the stalk fibre cellulose fiber after crushing adds water in beater Stir 2~6min;Then binder materials and admixture are sequentially added, 2~5min is stirred, solid content is 10~25%;Step 2, The slurry stirred be quickly poured into the mould of certain size and under 0.05~0.09MPa vacuum filtration pressure suction filtration to sample Product surface cure;Step 3, by the sample obtained by step 3 under 2.5~3.5MPa pressure 3~8min of pressurize, made Product;Step 4, product sealed in polybag and at ambient temperature place 1~2 day after, enter rower support or water support or steam Maintenance.
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CN106946540A (en) * 2017-03-01 2017-07-14 苏州顶裕节能设备有限公司 A kind of insulation material added with string and preparation method thereof
CN108623230A (en) * 2018-07-16 2018-10-09 桐城市景瑞建筑装饰工程有限公司 A kind of cement-based microporous building material
CN110183201A (en) * 2019-05-06 2019-08-30 浙江大东吴集团建设有限公司 A kind of green cement composite material
CN111302685A (en) * 2020-02-21 2020-06-19 郑州知淘信息科技有限责任公司 Preparation method of wheat straw fiber reinforced cement board and wheat straw fiber reinforced cement board
CN111892346A (en) * 2020-04-26 2020-11-06 东北电力大学 Environment-friendly modified straw fiber regenerated fine aggregate cement-based composite material and preparation method thereof
CN111549578A (en) * 2020-05-19 2020-08-18 南京紫晶藤节能科技有限公司 Energy-saving environment-friendly plate with good flame retardant property and manufacturing method thereof
CN111958760A (en) * 2020-08-18 2020-11-20 西南科技大学 Bamboo pulp cellulose fiber/hydrated magnesium silicate based composite material and preparation method thereof
CN112408902A (en) * 2020-11-12 2021-02-26 广东新元素板业有限公司 Preparation method of fiber-reinforced silicate board with high impact resistance

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CN101131036A (en) * 2007-07-26 2008-02-27 信阳木工机械有限责任公司 Stalk and cement mixed artificial board and manufacturing method thereof
CN101713236B (en) * 2009-11-30 2011-03-02 陈兆平 Light and high-strength wallboard made from fiber reinforced concrete and preparation method thereof
CN101885596A (en) * 2010-06-11 2010-11-17 北京交通大学 Plant fiber cement-based block material and preparation method thereof

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