建筑施工混凝土裂缝的预防与处理外文翻译、中英对照、英汉互译.docx

附录building construction concrete crack ofprevention and processing 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.the relative humidity is more low, cement syrup body stem suo more big, stem the suo crack be more easy creation.stem the suo crack is much surface parallel lines form or the net shallow thin crack, width many between 0.05-0.2 mm, the flat surface part much see in the big physical volume concrete and follow it more in thinner beam plank short to distribute.stem suo crack usually the anti- shen of influence concrete, cause the durable of the rust eclipse influence concrete of reinforcing bar, under the function of the water pressure dint would creation the water power split crack influence concrete of loading dint etc.concrete stem the suo be main with water ash of the concrete ratio, the dosage of the composition, cement of cement, gather to anticipate of the dosage of the property and dosage, in addition etc. relevant. 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/m3, 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. the alignment of the temperature crack usually none settle regulation, big area structure the crack often maneuver interleave;the size bigger structure of the beam plank length, the crack run parallel with short side more;thorough with pierce through sex of temperature crack general and short side direction parallelism or close parallelism, crack along long side cent the segment appear, in the center more airtight.crack width the size be different, be subjected to temperature variety influence more obvious, winter compare breadth, summer more narrow.the concrete temperature crack that the heat inflation cause is usually in the center the thick both ends be thin, but cold suo crack of thick thin variety not too obvious.the emergence of the this kind crack will cause the rust eclipse of reinforcing bar, the carbonization of concrete, the anti- jelly which lower concrete melt, anti- tired and anti- shen ability etc. 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/m3 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.ten is the supervision which strengthen concrete temperature, adopt to cool off in time, protection measure.11 is to reserve temperature constringency to sew.12 is to let up to control, sprinkle proper before building concrete in the ji rock and old concrete top build a 5 mm or so sand mat a layer or usage asphalt etc. material tu2 shua.13 is to strengthen concrete to protect, the concrete after sprinkle build use moist grass lian in time, hemp slices etc. overlay, and attention sprinkle water to protect, appropriate extension protect time, assurance the concrete surface be slow-moving cool off.at the cold season, concrete surface should constitution heat preservation measure, in order to prevent cold wave assault.14 is the allocation be a little amount in the concrete of reinforcing bar perhaps add fiber material concrete of temperature crack control at certain of scope inside.(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.(from:canadian journal of civil engineering)建筑施工混凝土裂缝的预防与处理混凝土工程中常见裂缝及预防:(1)干缩裂缝及预防 干缩裂缝一般较多出现在混凝土的养护后的一段时间,或者是混凝土浇筑完后的一周时间左右。随着水泥浆中水分的蒸发会慢慢产生干缩，而且这种收缩是不可恢复的。干缩裂缝的产生原因主要是由于混凝土内外水分的蒸发程度不同,从而而导致变形不同的结果：混凝土受外部条件的影响，表面水分损失过快，变形较大，内部湿度变化较小变形较小，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。相对湿度越低，水泥浆体干缩越大，干缩裂缝越易产生。干缩裂缝多为表面性的平行线状或网状浅细裂缝，宽度多在0.05-0.2mm之间，大体积混凝土中平面部位多见，较薄的梁板中多沿其短向分布。干缩裂缝通常会影响混凝土的抗渗性，引起钢筋的锈蚀影响混凝土的耐久性，在水压力的作用下会产生水力劈裂影响混凝土的承载力等等。混凝土干缩主要和混凝土的水灰比、水泥的成分、水泥的用量、集料的性质和用量、外加剂的用量等有关。主要预防措施：一是选用收缩量较小的水泥，一般采用中低热水泥和粉煤灰水泥，降低水泥的用量。二是混凝土的干缩受水灰比的影响较大，水灰比越大，干缩越大，因此在混凝土配合比设计中应尽量控制好水灰比的选用，同时掺加合适的减水剂。三是严格控制混凝土搅拌和施工中的配合比，混凝土的用水量绝对不能大于配合比设计所给定的用水量。四是加强混凝土的早期养护，并适当延长混凝土的养护时间。冬季施工时要适当延长混凝土保温覆盖时间，并涂刷养护剂养护。五是在混凝土结构中设置合适的收缩缝。(2)塑性收缩裂缝及预防塑性收缩是指混凝土在凝结之前，表面因失水较快而产生的收缩。塑性收缩裂缝一般在干热或大风天气出现，裂缝多呈中间宽、两端细且长短不一，互不连贯状态。较短的裂缝一般长20-30cm，较长的裂缝可达2-3m，宽1-5mm.其产生的主要原因为：混凝土在终凝前几乎没有强度或强度很小，或者混凝土刚刚终凝而强度很小时，受高温或较大风力的影响，混凝土表面失水过快，造成毛细管中产生较大的负压而使混凝土体积急剧收缩，而此时混凝土的强度又无法抵抗其本身收缩，因此产生龟裂。影响混凝土塑性收缩开裂的主要因素有水灰比、混凝土的凝结时间、环境温度、风速、相对湿度等等。主要预防措施：一是选用干缩值较小早期强度较高的硅酸盐或普通硅酸盐水泥。二是严格控制水灰比，掺加高效减水剂来增加混凝土的坍落度和和易性，减少水泥及水的用量。三是浇筑混凝土之前，将基层和模板浇水均匀湿透。四是及时覆盖塑料薄膜或者潮湿的草垫、麻片等，保持混凝土终凝前表面湿润，或者在混凝土表面喷洒养护剂等进行养护。五是在高温和大风天气要设置遮阳和挡风设施，及时养护。(3)沉陷裂缝及预防沉陷裂缝的产生是由于结构地基土质不匀、松软或回填土不实或浸水而造成不均匀沉降所致；或者因为模板刚度不足，模板支撑间距过大或支撑底部松动等导致，特别是在冬季，模板支撑在冻土上，冻土化冻后产生不均匀沉降，致使混凝土结构产生裂缝。此类裂缝多为深进或贯穿性裂缝，其走向与沉陷情况有关，一般沿与地面垂直或呈30-45角方向发展，较大的沉陷裂缝，往往有一定的错位，裂缝宽度往往与沉降量成正比关系。裂缝宽度受温度变化的影响较小。地基变形稳定之后，沉陷裂缝也基本趋于稳定。主要预防措施：一是对松软土、回填土地基在上部结构施工前应进行必要的夯实和加固。二是保证模板有足够的强度和刚度，且支撑牢固，并使地基受力均匀。三是防止混凝土浇灌过程中地基被水浸泡。四是模板拆除的时间不能太早，且要注意拆模的先后次序。五是在冻土上搭设模板时要注意采取一定的预防措施。(4)温度裂缝及预防温度裂缝多发生在大体积混凝土表面或温差变化较大地区的混凝土结构中。混凝土浇筑后，在硬化过