【正文】 forced concrete material of loading ability, durable and anti Shen ability, influence building of external appearance, service life, severity will threat arrive people39。t 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. Concrete crack creation of the reason be a lot of and have already transformed to cause of crack:Such as temperature variety, constringency, inflation, the asymmetry sink to sink etc. reason cause of crack。Protected environment not appropriate the crack etc. caused with chemical differentiation to treat in the actual engineering, work176。t 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 relative humidity is more low, cement syrup body stem Suo more big, stem the Suo crack be more easy the Suo crack is much surface parallel lines form or the shallow thin crack, width many between mm, the flat surface part much see in the big physical volume concrete and follow it more in thinner beam plank short to 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 建筑施工混凝土裂縫的預(yù)防與處理 –3– position, 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 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 acmodation of reduce is strict control concrete mix blend with under construction of match ratio, use of concrete water quantity absolute can39。s much presenting in the center breadth, both ends be in the centerthin and the length be different, with each other not coherent crack general long 2030 cm, the longer crack can reach to a 23 m, breadth 15 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 pare 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 can39。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 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 30 176。 Cape direction development, bigger sink to sink crack, usually have certain of wrong, crack width usually with sink to decline quantity direct proportion width under the influence of temperature variety 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 is the strength that assurance template is enough and just degree, and prop up firm, and make the foundation be subjected to dint is keep concrete from sprinkle infusing the foundation in the process is soak by is time that template tore down to can39。The size bigger structure of the beam plank length, the crack run parallel with short side more。s etc. overlay, and attention sprinkle water to protect, appropriate extension protect time, assurance the concrete surface be slowmoving cool the cold season, concrete surface should constitution heat preservation measure, in order to prevent cold wave is the 建筑施工混凝土裂縫的預(yù)防與處理 –7– 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. and prevention that the chemical reaction cause Alkali bone39。t have the surface crack of influence and deep enter crack of 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