建筑施工混凝土裂縫的主要種類外文翻譯

1、<p><b>　　畢業(yè)英語翻譯</b></p><p><b>　　專業(yè)：土木工程</b></p><p><b>　　姓名：馬偉</b></p><p>　　學號：090320615</p><p>　　建筑施工混凝土裂縫的主要種類</p><

2、p><b>　　1、干縮裂縫　　</b></p><p>　　干縮裂縫多出現在混凝土養(yǎng)護結束后的一段時間或是混凝土澆筑完畢后的一周左右。水泥漿中水分的蒸發(fā)會產生干縮，且這種收縮是不可逆的。干縮裂縫的產生主要是由于混凝土內外水分蒸發(fā)程度不同而導致變形不同的結果：混凝土受外部條件的影響，表面水分損失過快，變形較大，內部濕度變化較小變形較小，較大的表面干縮變形受到混凝土內部約束，產生較大拉應

3、力而產生裂縫。相對濕度越低，水泥漿體干縮越大，干縮裂縫越易產生。干縮裂縫多為表面性的平行線狀或網狀淺細裂縫，寬度多在0.05-0.2mm之間，大體積混凝土中平面部位多見，較薄的梁板中多沿其短向分布。干縮裂縫通常會影響混凝土的抗?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產生水力劈裂影響混凝土的承載力等等?；炷粮煽s主要和混凝土的水灰比、水泥的成分、水泥的用量、集料的性質和用量、外加劑的用量等有關。</p>&

4、lt;p><b>　　2、塑性收縮裂縫</b></p><p>　　塑性收縮是指混凝土在凝結之前，表面因失水較快而產生的收縮。塑性收縮裂縫一般在干熱或大風天氣出現，裂縫多呈中間寬、兩端細且長短不一，互不連貫狀態(tài)。較短的裂縫一般長20-30cm，較長的裂縫可達2-3m，寬1-5mm.其產生的主要原因為：混凝土在終凝前幾乎沒有強度或強度很小，或者混凝土剛剛終凝而強度很小時，受高溫或較大風力

5、的影響，混凝土表面失水過快，造成毛細管中產生較大的負壓而使混凝土體積急劇收縮，而此時混凝土的強度又無法抵抗其本身收縮，因此產生龜裂。影響混凝土塑性收縮開裂的主要因素有水灰比、混凝土的凝結時間、環(huán)境溫度、風速、相對濕度等等。</p><p><b>　　3、沉陷裂縫</b></p><p>　　沉陷裂縫的產生是由于結構地基土質不勻、松軟或回填土不實或浸水而造成不均勻沉降

6、所致；或者因為模板剛度不足，模板支撐間距過大或支撐底部松動等導致，特別是在冬季，模板支撐在凍土上，凍土化凍后產生不均勻沉降，致使混凝土結構產生裂縫。此類裂縫多為深進或貫穿性裂縫，其走向與沉陷情況有關，一般沿與地面垂直或呈30°-45°角方向發(fā)展，較大的沉陷裂縫，往往有一定的錯位，裂縫寬度往往與沉降量成正比關系。裂縫寬度受溫度變化的影響較小。地基變形穩(wěn)定之后，沉陷裂縫也基本趨于穩(wěn)定。</p><p&

7、gt;<b>　　4、溫度裂縫</b></p><p>　　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)的混凝土結構中?；炷翝仓?，在硬化過程中，水泥水化產生大量的水化熱，（當水泥用量在350-550 kg/m3，每立方米混凝土將釋放出17500-27500kJ的熱量，從而使混凝土內部溫度升達70℃左右甚至更高）。由于混凝土的體積較大，大量的水化熱聚積在混凝土內部而不易散發(fā)，導致內部

8、溫度急劇上升，而混凝土表面散熱較快，這樣就形成內外的較大溫差，較大的溫差造成內部與外部熱脹冷縮的程度不同，使混凝土表面產生一定的拉應力。當拉應力超過混凝土的抗拉強度極限時，混凝土表面就會產生裂縫，這種裂縫多發(fā)生在混凝土施工中后期。在混凝土的施工中當溫差變化較大，或者是混凝土受到寒潮的襲擊等，會導致混凝土表面溫度急劇下降，而產生收縮，表面收縮的混凝土受內部混凝土的約束，將產生很大的拉應力而產生裂縫，這種裂縫通常只在混凝土表面較淺的范圍內產

9、生。</p><p>　　溫度裂縫的走向通常無一定規(guī)律，大面積結構裂縫?？v橫交錯；梁板類長度尺寸較大的結構，裂縫多平行于短邊；深入和貫穿性的溫度裂縫一般與短邊方向平行或接近平行，裂縫沿著長邊分段出現，中間較密。裂縫寬度大小不一，受溫度變化影響較為明顯，冬季較寬，夏季較窄。高溫膨脹引起的混凝土溫度裂縫是通常中間粗兩端細，而冷縮裂縫的粗細變化不太明顯。此種裂縫的出現會引起鋼筋的銹蝕，混凝土的碳化，降低混凝土的抗凍融、

10、抗疲勞及抗?jié)B能力等。</p><p>　　5、化學反應引起的裂縫</p><p>　　堿骨料反應裂縫和鋼筋銹蝕引起的裂縫是鋼筋混凝土結構中最常見的由于化學反應而引起的裂縫。</p><p>　　混凝土拌和后會產生一些堿性離子，這些離子與某些活性骨料產生化學反應并吸收周圍環(huán)境中的水而體積增大，造成混凝土酥松、膨脹開裂。這種裂縫一般出現中混凝土結構使用期間，一旦出現很難

11、補救，因此應在施工中采取有效措施進行預防。主要的預防措施：一是選用堿活性小的砂石骨料。二是選用低堿水泥和低堿或無堿的外加劑。三是選用合適的摻和料抑制堿骨料反應。</p><p>　　由于混凝土澆筑、振搗不良或者是鋼筋保護層較薄，有害物質進入混凝土使鋼筋產生銹蝕，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。通常的預防措施有：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

12、凝土澆注要振搗密實。四是鋼筋表層涂刷防腐涂料。</p><p><b>　　結 論</b></p><p>　　裂縫是混凝土結構中普遍存在的一種現象，它的出現不僅會降低建筑物的抗?jié)B能力，影響建筑物的使用功能，而且會引起鋼筋的銹蝕，混凝土的碳化，降低材料的耐久性，影響建筑物的承載能力，因此要對混凝土裂縫進行認真研究、區(qū)別對待，采用合理的方法進行處理，并在施工中采取各種有

13、效的預防措施來預防裂縫的出現和發(fā)展，保證建筑物和構件安全、穩(wěn)定地工作。</p><p>　　Building construction concrete crack of</p><p>　　prevention and processing</p><p>　　1.Stem Suo crack </p><p>　　Stem the Suo

14、 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

15、 of constringency is can't 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

16、subjected to exterior condition of influence, surfac</p><p>　　2.The Su constringency crack </p><p>　　Su constringency is the concrete is before condense, surface because of lose water quicker bu

17、t creation of constringency.The Su constringency crack is general at dry heat or strong wind the weather appear, crack's much presenting in the center breadth, both ends be in the centerthin and the length be differe

18、nt, 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</p><p>　　3.Sink

19、 to sink crack</p><p>　　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 th

20、e 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 t

21、emplate prop up at jelly soil up, jelly the soil turn jelly empress creation asymmetry to sink to</p><p>　　4.Temperature crack </p><p>　　Temperature crack much the occurrence is in big surface o

22、r 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

23、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

24、 ℃ </p><p>　　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 pa

25、rallel 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 airti

26、ght.Crack width the size be different, be subjected to temperature variety influence m</p><p>　　5.Crack that the chemical reaction cause</p><p>　　Alkali bone's anticipating the crack that re

27、action 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.</p><p>　　The concrete blend a future reunion

28、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, infl

29、ation 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 prevent

30、ion measure:While being </p><p>　　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 cr

31、eation 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.Us

32、ually of prevent measure from have:One is assurance reinforcing bar protection the thickness of the layer.T</p><p>　　Conclusion</p><p>　　The crack is widespread in the concrete structure existen

33、ce 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,

34、 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 unde