【正文】 ucture whole of repair, it is make use of pressure equipments gum knot the material press into the crack of concrete, gum knot the material harden behind and concrete formation one be whole, thus reinforce of in mon use gum knot material has the cement the syrup, epoxy, A Ji C Xi sour ester and gather ammonia ester to equalize to learn material. The Qian sew a method is that the crack be a kind of most in mon use method in, it usually is follow the crack dig slot, the Qian fill Su in the slot or rigid water material with attain closing crack of in mon use Su material has PVC gum mire, plastics ointment, the D Ji rubber etc.。Perhaps because of template just degree 浙江大學(xué)城市學(xué)院畢業(yè)設(shè)計(jì) 外文翻譯 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。t appear crack possibly or as 浙江大學(xué)城市學(xué)院畢業(yè)設(shè)計(jì) 外文翻譯 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。三是選用合適的摻和料抑制堿骨料反應(yīng)。十三是加強(qiáng)混凝土養(yǎng)護(hù)，混凝土澆筑后，及時(shí)用濕潤(rùn)的草簾、麻片等覆蓋，并注意灑水養(yǎng)護(hù)，適當(dāng)延長(zhǎng)養(yǎng)護(hù)時(shí)間，保證混凝土表面緩慢冷卻。五是改善混凝土的攪拌加工工藝，降低混凝土的澆筑溫度。 溫度裂縫的走向通常無(wú)一定規(guī)律，大面積結(jié)構(gòu)裂縫常縱橫交錯(cuò)；梁板類(lèi)長(zhǎng)度尺寸浙江大學(xué)城市學(xué)院畢業(yè)設(shè)計(jì) 外文翻譯 較大的結(jié)構(gòu)，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(zhǎng)邊分段出現(xiàn)，中間較密。三是防止混凝土澆灌過(guò)程中地基被水浸泡。 沉陷裂縫及預(yù)防 沉陷裂縫的產(chǎn)生 是由于結(jié)構(gòu)地基土質(zhì) 不均勻、松軟、 回填土不實(shí)或浸水而造成不均勻沉降所致；或者因?yàn)槟０鍎偠炔蛔?，模板支撐間距過(guò)大或支撐底部松動(dòng)等導(dǎo)致，特別是在冬季，模板支撐在凍土上，凍土化凍后產(chǎn)生不均勻沉降，致使混凝土結(jié)構(gòu)產(chǎn)生裂縫。塑性收縮裂縫一般 會(huì) 在干熱或 者 大風(fēng)天氣出現(xiàn)，裂縫多呈 現(xiàn)形狀為 中間寬、兩端細(xì)且長(zhǎng)短不一，互不連貫狀態(tài)。混凝土干縮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(zhì)和用量、外加劑的用量等有關(guān)。 混 凝土裂縫產(chǎn)生的原因很多，有變形引起的裂縫：如溫度變化、收縮、膨脹、不均勻沉陷等原因引起的裂縫；外 荷 載作用引起的裂縫；養(yǎng)護(hù)環(huán)境不當(dāng)和化學(xué)作用引起的裂縫等等。由于混凝土施工和自身 變形、約束等一系列 的問(wèn)題，硬化成型的混凝土中存在許 多的微小孔隙、氣孔和微裂縫， 由于這些初始缺陷的存在才使 得 混凝土呈現(xiàn)出一些非均質(zhì)的特性。 混凝土建筑和構(gòu)件通常都是帶縫工作的 ，由于裂縫的存在和發(fā)展通常會(huì)使內(nèi)部的鋼筋 產(chǎn)生腐蝕，降低鋼筋混凝土材料 的 承載能力、耐久性及抗?jié)B能力，影響建筑物的外觀、使用壽命， 將會(huì) 嚴(yán)重威脅到人們的生命和財(cái)產(chǎn)安全。水泥漿中水分不斷的蒸發(fā)會(huì)產(chǎn)生干縮現(xiàn)象，且這種收縮是不可恢復(fù) 的。三是嚴(yán)格控制混凝土攪拌和施工中的配合比，混凝土在拌合中的 用水量絕對(duì)不能大于配合比設(shè)計(jì)所給定的用水量。 主要預(yù)防措施：一是選用干縮值較 小早期強(qiáng)度較高的硅酸鹽或普通硅酸鹽水泥。 角方向發(fā)展，較大的沉陷裂縫，往往有一定的錯(cuò)位，裂縫寬度往往與沉降量成正比關(guān)系。 溫度裂縫及預(yù)防 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。此種裂縫的出現(xiàn)會(huì)引起鋼筋的銹蝕，混凝土的碳化，降低混凝土的抗凍融、抗疲勞及抗?jié)B能力等。八是大體積混凝土的溫度應(yīng)力與結(jié)構(gòu)尺寸相關(guān)，混凝土結(jié)構(gòu)尺寸越大，溫度應(yīng)力越大，因此要合理安排施工工序，分層、分塊澆筑，以利于散熱，減小約束。 化學(xué)反應(yīng)引起的裂縫及預(yù)防 堿骨料反應(yīng)裂縫和鋼筋銹蝕引起的裂縫是鋼筋混凝土結(jié)構(gòu)中最常見(jiàn)的由于化學(xué)反應(yīng)而引起的裂縫。二是混凝土級(jí)配要良好。out a problem according to the actual circumstance. 2 In the concrete engineering the familiar crack and the prevention 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 plete behind of around a the cement syrup humidity of evaporate would creation stem Suo, and this kind of constringency is can39。t be too early, and want to notice to dismantle a mold order of is at jelly soil top take to establish template to notice to adopt certain of prevention measure. Temperature crack and prevention Temperature 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 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 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 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 the concrete of under construction be difference in temperature variety more big, perhaps is a concrete to be subjected to assault of cold wave 浙江大學(xué)城市學(xué)院畢業(yè)設(shè)計(jì) 外文翻譯 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 interle