【正文】 筑、振搗不良或者是鋼筋保護層較薄，有害物質(zhì)進入混凝土使鋼筋產(chǎn)生銹蝕，銹蝕的鋼筋體積膨脹，導致混凝土脹裂，此種類型的裂縫多為縱向裂縫，沿鋼筋的位置出現(xiàn)。通常的預(yù)防措施有：一是保證鋼筋保護層的厚度。二是混凝土級配要良好。三是混凝土澆注要振搗密實。四是鋼筋表層涂刷防腐涂料。 出自《加拿大土木工程學報》附件2：外文原文（復(fù)印件）Building construction concrete crack ofprevention and processingAbstractThe 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 Concrete39。s 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 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 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 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 people39。s life and property lot of all of crash of engineerings is because of the unsteady development of the crack with the result 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 reinforced concrete norm is also explicit provision:Some structure at place of dissimilarity under the condition allow existence certain the crack of at under construction should as far as possible adopt a valid measure control crack creation, make the structure don39。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。Have outside carry the crack that the function cause。Protected environment not appropriate the crack etc. caused with chemical differentiation to treat in the actual engineering, work176。out a problem according to the actual circumstance. In the concrete engineering the familiar crack and the prevention 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 plete behind of around a the cement syrup humidity of evaporate would creation stem Suo, and this kind of constringency is can39。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 conc