建筑施工混凝土裂缝的预防与处理

毕业设计外文文献翻译院 系：厦门理工学院土木工程与建筑系年级专业： 姓 名： 学 号： 附 件：建筑施工混凝土裂缝的预防与处理 Building construction concrete crack of prevention and processingAbstract：The crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure. Keyword:Concrete crack prevention processingForeword： Concretes ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use function not a creation to endanger.But after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the aid of instruments of macro view the crack be also the crack that the concrete often say in the engineering. Concrete building and Gou piece usually all take sewer to make of, because of crack of existence and development usually make inner part of reinforcing bar etc. material creation decay, lower reinforced concrete material of loading ability, durable and anti- Shen ability, influence building of external appearance, service life, severity will threat arrive peoples life and property safety.A lot of all of crash of engineerings is because of the unsteady development of the crack with the result that.Modern age science research with a great deal of of the concrete engineering practice certificate, in the concrete engineering crack problem is ineluctable, also acceptable in certainly of the scope just need to adopt valid of measure will it endanger degree control at certain of scope inside.The reinforced concrete norm is also explicit provision:Some structure at place of dissimilarity under the condition allow existence certain the crack of width.But at under construction should as far as possible adopt a valid measure control crack creation, make the structure dont appear crack possibly or as far as possible decrease crack of amount and width, particularly want to as far as possible avoid harmful crack of emergence, insure engineering quality thus. In the concrete engineering the familiar crack and the prevention 1.Stem Suo crack and prevention Stem the Suo crack much appear after the concrete protect be over of a period of time or concrete sprinkle to build to complete behind of around a week.In the cement syrup humidity of evaporate would creation stem Suo, and this kind of constringency is cant negative.Stem Suo crack of the creation be main is because of concrete inside outside humidity evaporate degree dissimilarity but cause to transform dissimilarity of result:The concrete is subjected to exterior condition of influence, surface humidity loss lead quick, transform bigger, inner part degree of humidity variety smaller transform smaller, bigger surface stem the Suo transform to be subjected to concrete inner part control, creation more big pull should dint but creation crack. Main prevention measure:While being to choose to use the constringency quantity smaller cement, general low hot water mire and powder ash from stove cement in the adoption, lower the dosage of cement.Two is a concrete of stem the Suo be subjected to water ash ratio of influence more big, water ash ratio more big, stem Suo more big, so in the concrete match the ratio the design should as far as possible control good water ash ratio of choose to use, the Chan add in the meantime accommodation of reduce water.Three is strict control concrete mix blend with under construction of match ratio, use of concrete water quantity absolute cant big in match ratio design give settle of use water quantity.Four is the earlier period which strengthen concrete to protect, and appropriate extension protect of concrete time.Winter construction want to be appropriate extension concrete heat preservation to overlay time, and Tu2 Shua protect to protect.Five is a constitution the accommodation is in the concrete structure of the constringency sew. 2.The Su constringency crack and prevention Su constringency is the concrete is before condense, surface because of lose water quicker but creation of constringency.The Su constringency crack is general at dry heat or strong wind the weather appear, cracks much presenting in the center breadth, both ends be in the centerthin and the length be different, with each other not coherent appearance.Shorter crack general long 20-30 cm, the longer crack can reach to a 2-3 m, breadth 1-5 mm.It creation of main reason is:The concrete is eventually almost having no strength or strength before the Ning very small, perhaps concrete just eventually Ning but strength very hour, be subjected to heat or compare strong wind dint of influence, the concrete surface lose water to lead quick, result in in the capillary creation bigger negative press but make a concrete physical volume sharply constringency, but at this time the strength of concrete again cant resist its constringency, therefore creation cracked.The influence concrete Su constringency open the main factor of crack to have water ash ratio, concrete of condense time, environment temperature, wind velocity, relative humidity.etc. Main prevention measure:One is choose to use stem the Suo value smaller higher Huo sour salt of the earlier period strength or common the Huo sour brine mire.Two is strict the control water ash ratio, the Chan add to efficiently reduce water to increment the collapse of concrete fall a degree and with easy, decrease cement and water of dosage.Three is to sprinkle before building concrete, water basic level and template even to soak through.Four is in time to overlay the perhaps damp grass mat of the plastics thin film, hemp slice etc., keep concrete eventually before the Ning surface is moist, perhaps spray to protect etc. to carry on protect in the concrete surface.Five is in the heat and strong wind the weather to want to establish to hide sun and block breeze facilities, protect in time. 3.Sink to sink crack and prevention The creation which sink to sink crack is because of the structure foundation soil quality not and evenly, loose soft or return to fill soil dishonest or soak in water but result in the asymmetry sink to decline with the result that;Perhaps because of template just degree shortage, the template propped up to once be apart from big or prop up bottom loose move etc. to cause, especially at winter, the template prop up at jelly soil up, jelly the soil turn jelly empress creation asymmetry to sink to decline and cause concrete structure creation crack.This kind crack many is deep enter or pierce through sex crack, it alignment have something to do with sinking to sink a circumstance, general follow with ground perpendicular or present 30 s-45 Cape direction development, bigger sink to sink crack, usually have certain of wrong, crack width usually with sink to decline quantity direct proportion relation.Crack width under the influence of temperature variety smaller.The foundation after transform stability sink to sink crack also basic tend in stability. Main prevention measure:One is rightness loose soft soil, return to fill soil foundation a construction at the upper part structure front should carry on necessity of Hang solid with reinforce.Two is the strength that assurance template is enough and just degree, and prop up firm, and make the foundation be subjected to dint even.Three is keep concrete from sprinkle infusing the foundation in the process is soak by water.Four is time that template tore down to cant be too early, and want to notice to dismantle a mold order of sequence.Five is at jelly soil top take to establish template to notice to adopt certain of prevention measure. 4.Temperature crack and prevention Temperature crack much the occurrence is in big surface or difference in temperature variety of the physical volume concrete compare the earth area of the concrete structure.Concrete after sprinkling to build, in the hardening the process, cement water turn a creation a great deal of of water turn hot, .(be the cement dosage is in the 350-550 kg/m 3, each sign square the rice concrete will release a calories of 17500-27500 kJ and make concrete internal thus the temperature rise to reach to 70 or so even higher)Because the physical volume of concrete be more big, a great deal of of water turn hot accumulate at the concrete inner part but not easy send forth, cause inner part the temperature hoick, but the concrete surface spread hot more quick, so formation inside outside of bigger difference in temperature, the bigger difference in temperature result in inner part and exterior hot the degree of the bulge cold Suo dissimilarity, make concrete surface creation certain of pull should dint.When pull should dint exceed the anti- of concrete pull strength extreme limit, concrete surface meeting creation crack, this kind of crack much occurrence after the concrete under construction period.In the concrete of under construction be difference in temperature variety more big, perhaps is a concrete to be subjected to assault of cold wave etc., will cause concrete surface the temperature sharply descend, but creation constringency, surface constringency of the concrete be subjected to inner part concrete of control, creation very big of pull should dint but creation crack, this kind of crack usually just in more shallow scope of the concrete surface creation.Main prevention measure:One is as far as possible choose to use low hot or medium hot water mire, like mineral residue cement, powder ash from stove cement.etc.Two is a decrease cement dosage, cement dosage as far as possible the control is in the 450 kg/m 3 following.Three is to lower water ash ratio, water ash of the general concrete ratio control below 0.6.Four is improvement the bone anticipate class to go together with, the Chan add powder ash from stove or efficiently reduce water etc. to come to reduce cement dosage and lower water to turn hot.Five is an improvement concrete of mix blend to process a craft, lower sprinkle of concrete to build temperature.Six is the in addition that the Chan add a have of fixed amount to reduce water and increase Su, slow Ning etc. function in the concrete, improvement the concrete mix to match a thing of mobility, protect water, lower water to turn hot, postpone hot Feng of emergence time.Seven is the heat season sprinkle to build can the adoption take to establish to hide sun plank etc. assistance measure control concrete of Wen Sheng, lower to sprinkle temperature of build the concrete.Eight is the temperature of big physical volume concrete should the dint relate to structure size, concrete structure size more big, temperature should dint more big, so want reasonable arrangement construction work preface, layering, cent the piece sprinkle to build, for the convenience of in spread hot, let up control.Nine is at great inner part constitution of the physical volume concrete cool off piping, cold water perhaps cold air cool off, let up concrete of inside outside difference in temperature.5.Crack and prevention that the chemical reaction cause Alkali bones anticipating the crack that reaction crack and reinforcing bar rust eclipse cause is the most familiar in the reinforced concrete structure of because of chemical reaction but cause of crack. The concrete blend a future reunion creation some alkalescence ion, these ion with some activity the bone anticipate creation chemical reaction and absorb surroundings environment in of water but the physical volume enlarge, make concrete crisp loose, inflation open crack.In this kind of crack general emergence concrete structure usage period, once appear very difficult remediable, so should at under construction adopt valid the measure carry on prevention.Main of prevention measure:While being to choose to anticipate with the alkali activity small freestone bone.Two is the in addition which choose to use low lye mire with low alkali or have no alkali.Three is the Chan which choose to use accommodation with anticipate to repress an alkali bone to anticipate reaction. Because the concrete sprinkle to build, flap Dao bad perhaps is a reinforcing bar protection layer thinner, the harmful material get into concrete to make reinforcing bar creation rust eclipse, the reinforcing bar physical volume of the rust eclipse inflation, cause concrete bulge crack, the crack of this kind type much is a crack lengthways, follow the position of reinforcing bar appear.Usually of prevent measure from have:One is assurance reinforcing bar protection the thickness of the layer.Two is a concrete class to go together with to want good.Three is a concrete to sprinkle to note and flap Dao airtight solid.Four is a reinforcing bar surface layer Tu2 Shua antisepsis coating.Crack processing The emergence of the crack not only would influence structure of whole with just degree, return will cause the rust eclipse of reinforcing bar, acceleration concrete of carbonization, lower durable and anti- of concrete tired, anti- Shen ability.Therefore according to the property of crack and concrete circumstance we want differentiation to treat, in time processing, with assurance building of safety usage. The repair measure of the concrete crack is main to have the following some method:Surface repair method, infuse syrup, the Qian sew method, the structure reinforce a method, concrete displacement method, electricity chemistry protection method and imitate to living from heal method. Surface repair the method be a kind of simple, familiar of repair method, it main be applicable to stability and to structure loading the ability dont have the surface crack of influence and deep enter crack of processing.The processing measure that is usually is a surface in crack daubery cement syrup, the wreath oxygen gum mire or at concrete surface Tu2 Shua paint, asphalt etc. antisepsis material, at protection of in the meantime for keeping concrete from continue under the influence of various function to open crack, usually can adoption the surface in crack glue to stick glass fiber cloth etc. measure. 1, infuse syrup, the Qian sew method Infuse a syrup method main the concrete crack been applicable to have influence or have already defend Shen request to the structure whole of repair, it is make use of pressure equipments gum knot the material press into the crack of concrete, gum knot the material harden behind and concrete formation one be whole, thus reinforce of purpose.The in common use gum knot material has the cement the syrup, epoxy, A Ji C Xi sour ester and gather ammonia ester to equalize to learn material. The Qian sew a method is that the crack be a kind of most in common use method in, it usually is follow the crack dig slot, the Qian fill Su in the slot or rigid water material with attain closing crack of purpose.The in common use Su material has PVC gum mire, plastics ointment, the D Ji rubber etc.;In common use rigid water material is the polymer cement sand syrup. 2, the structure reinforce a method When the crack influence arrive concrete structure of function, will consideration adopt to reinforce a method to carry on processing to the concrete structure.The structure reinforce medium in common use main have the following a few method:The piece of enlargement concrete structure in every aspect accumulate, outside the Cape department of the Gou piece pack type steel, adoption prepare should the dint method reinforce, glue to stick steel plate to reinforce, increase to establish fulcrum to reinforce and jet the concrete compensation reinforce. 3, concrete displacement methodConcrete displacement method is processing severity damage concrete of a kind of valid method, this method be first will damage of the concrete pick and get rid of, then again displacement go into new of concrete or other material.The in common use displacement material have:Common concrete or the cement sand syrup, polymer or change sex polymer concrete or sand syrup. 4, the electricity chemistry protection methodThe electricity chemistry antisepsis is to make use of infliction electric field in lie the quality of electricity chemical effect, change concrete or reinforced concrete the environment appearance of the place, the bluntness turn reinforcing bar to attain the purpose of antisepsis.Cathode protection method, chlorine salts withdrawing a method, alkalescence to recover a method is a chemistry protection method in three kinds of in common use but valid method.The advantage of this kind of method is a protection method under the influence of environment factor smaller, apply reinforcing bar, concrete of long-term antisepsis, since can used for crack structure already can also used for new set up structure. 5, imitate to living from legal moreImitate to living from heal the method be a kind of new crack treatment, its mimicry living creature organization secrete a certain material towards suffering wound part auto, but make the wound part heal of function, join some and special composition(such as contain to glue knot of the liquid Xin fiber or capsule) in the concrete of the tradition the composition, at concrete inner part formation the intelligence type imitate to living from heal nerve network system, be the concrete appear crack secrete a parts of liquid Xin fiber can make the crack re- heal. Conclusion：The crack is widespread in the concrete structure existence of a kind of phenomenon, it of emergence not only will lower the anti- Shen of building ability, influence building of usage function, and will cause the rust eclipse of reinforcing bar, the carbonization of concrete, lower the durable of material, influence building of loading ability, so want to carry on to the concrete crack earnest research, differentiation treat, adoption reasonable of the method carry on processing, and at under construction adopt various valid of prevention measure to prevention crack of emergence and development, assurance building and Gou piece safety, stability work.外文文献翻译文建筑施工混凝土裂缝的预防与处理摘要：建筑施工中一个普遍存在而又难于解决的工程实际问题是混凝土的裂缝问题，本文对混凝土工程中常见的裂缝问题进行探讨与分析，并且针对具体情况，提出了一些预防、处理措施。关键词：混凝土 裂缝 预防 处理前言：混凝土是由砂石骨料、水泥、水和其加材料混合成的非均质脆性材料。因为混凝土施工及自身变形、约束等问题，成型的混凝土中有着很多微孔隙、气穴和小的裂缝，正是因为这些缺陷的存在才使混凝土呈现出它的非均质的特点。细小的裂缝通常是一种无危害的裂缝，对混凝土的防渗，承重及其他使用功能是不产生危害。但在混凝土受到外加荷载或者温差等作用后，它的微裂缝就开始不断的扩展和连通，最后就会形成我们肉眼可见的大的裂缝，就是混凝土工程中通常说到的裂缝。混凝土建筑与构件一般是带缝在工作的，由于裂缝发展通常会使里面的钢筋材料产生腐蚀，从而降低了钢筋混凝土材料的各种性能，影响外观、使用寿命，严重者还会威胁到人们的安全。由于裂缝的不稳定发展导致很多工程的出事。最近科学研究和很多的混凝土工程证明，裂缝问题是不可避免的，在一定的允许范围内还是可以接受的，只要采取有效的手段将它的危害控制在一定的范围之内。钢筋混凝土规范规定：一些结构在不同条件下，允许有一定大小的裂缝。但是在混凝土施工过程中应尽量采取有效方法控制裂缝的产生，使结构尽量不出现或减少裂缝的数量和宽度，尤其要尽量避免对建筑有害裂缝的出现，确保工程质量。混凝土工程中常见裂缝及预防:1.干缩裂缝及预防在混凝土养护结束后的一段时间或是混凝土浇筑完毕后的一周左右多会出现干缩裂缝。水泥浆中的水分蒸发会使混凝土干缩，并且收缩是不可逆的。混凝土内外水分蒸发程度不同而导致的结果实干缩裂缝产生的主要原因：混凝土受外部因素的影响，表面水分很快消失，引起变形较大，内部水分变化较小所以变形较小，较大的表面干缩变形受到混凝土内部约束，产生较大拉应力而产生裂缝。主要预防措施：一是使用收缩量小的水泥，一般可以用中低热水泥或者粉煤灰水泥，降低水泥的用量。二是水灰比的影响混凝土的干缩量较大，水灰比大，则混凝土干缩越大，因此在混凝土的配合比应控制好水灰比，同时还要掺加适量的减水剂。三是尽量控制混凝土搅拌与施工中的配合比，混凝土搅拌时的用水量一定不能大于设计所给定的用水量。四是注意混凝土的早期养护，并且应该适当加长养护时间。在冬季施工的时候，应适当的加长混凝土保温覆盖时间，并涂刷养护剂。五是合适的收缩缝。2.塑性收缩裂缝及预防塑性收缩指的是混凝土在凝结之前，因为表面失水快而产生的收缩。这种情况一般在干热以及