【正文】 e part much see in the big physical volume concrete and follow it more in thinner beam plank short to Suo crack usually the antiShen 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 position, cement of cement, gather to anticipate of the dosage of the property and dosage, in addition Su constringency crack and preventionSu constringency is the concrete is before condense, surface because of lose water quicker but creation of Su constringency crack is general at dry heat or strong wind the weather appear, crack39。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 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 , 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 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 cause of crack。Have outside carry the crack that the function cause。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。 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 crack and preventionTemperature crack much the occurrence is in big surface or difference in temperature variety of the physical volume concrete pare the earth area of the 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 350550 kg/m 3, each sign square the rice concrete will release a calories of 1750027500 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 pullshould dint exceed the antiof concrete pull strength extreme limit, concrete surface meeting creation crack, this kind of crack much occurrence after the concrete under construction 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 The crack is widespread in the concrete structure existence of a kind of phenomenon, it of emergence not only will lower the antiShen 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 《CANADIAN JOURNAL OF CIVIL ENGINEERING》建筑施工混凝土裂縫混凝土的裂縫問題是一個(gè)普遍存在而又難于解決的工程實(shí)際問題，本文對(duì)混凝土工程中常見的一些裂縫問題進(jìn)行了探討分析。但是在混凝土受到荷載、溫差等作用之后，微裂縫就會(huì)不斷的擴(kuò)展和連通，最終形成我們?nèi)庋劭梢姷暮暧^裂縫，也就是混凝土工程中常說(shuō)的裂縫。水泥漿中水分的蒸發(fā)會(huì)產(chǎn)生干縮，且這種收縮是不可逆的。干縮裂縫通常會(huì)影響混凝土的抗?jié)B性，引起鋼筋的銹蝕影響混凝土的耐久性，在水壓力的作用下會(huì)產(chǎn)生水力劈裂影響混凝土的承載力等等。較短的裂縫一般長(zhǎng)2030cm，較長(zhǎng)的裂縫可達(dá)23m，：混凝土在終凝前幾乎沒有強(qiáng)度或強(qiáng)度很小，或者混凝土剛剛終凝而強(qiáng)度很小時(shí)，受高溫或較大風(fēng)力的影響，混凝土表面失水過快，造成毛細(xì)管中產(chǎn)生較大的負(fù)壓而使混凝土體積急劇收縮，而此時(shí)混凝土的強(qiáng)度又無(wú)法抵抗其本身收縮，因此產(chǎn)生龜裂。45176。溫度裂縫多發(fā)生在大體積混凝土表面或溫差變化較大地區(qū)的混凝土結(jié)構(gòu)中。在混凝土的施工中當(dāng)溫差變化較大，或者是混凝土受到寒潮的襲擊等，會(huì)導(dǎo)致混凝土表面溫度急劇下降，而產(chǎn)生收縮，表面收縮的混凝土受內(nèi)部混凝土的約束，將產(chǎn)生很大的拉應(yīng)力而產(chǎn)生裂縫，這種裂縫通常只在混凝土表面較淺的范圍內(nèi)產(chǎn)生。在實(shí)習(xí)的過程當(dāng)中我們涉及到了以下的內(nèi)容：對(duì)所在實(shí)習(xí)工程的建筑、結(jié)構(gòu)施工圖的識(shí)讀；對(duì)工程的性質(zhì)、規(guī)模、建筑物及結(jié)構(gòu)體系，地基及基礎(chǔ)特點(diǎn)等的了解；對(duì)土方工程的特點(diǎn)及回填土的質(zhì)量要求的了解；對(duì)實(shí)心磚墻的砌筑方法、墻體的構(gòu)造要求的了解；對(duì)混凝土的制備、運(yùn)輸、澆筑、振搗及養(yǎng)護(hù)拆模的方法的了解；對(duì)混凝土的質(zhì)量檢查內(nèi)容及檢查方法的掌握；對(duì)鋼筋的除銹、調(diào)直、切斷、彎曲成型等加工工藝以及鋼筋連接的方法及要