【正文】 定的范圍內(nèi)也是可以接受的，但 要采取有效的措施將其危害程度控制在一定的范圍之內(nèi)。冬季施工時(shí)要適當(dāng)延長混凝土 的保溫覆蓋時(shí)間，并涂刷保護(hù)劑保 護(hù)。地基變形穩(wěn)定之后，沉陷裂縫也基本趨于穩(wěn)定。二是減少水泥用量， 將水泥用量盡量控制在 450kg/m3 以下。這種裂縫一般出現(xiàn)中混凝土結(jié)構(gòu)使用期間，一旦出現(xiàn)很難補(bǔ)救，因此應(yīng)在施工中采取有效措施進(jìn)行預(yù)防。t big in match ratio design give settle of use water quantity. Four is the earlier period which strengthen concrete to protect, and appropriate extension protect of concrete time. Winter construction want to be appropriate extension concrete heat preservation to overlay time, and Tu2 Shua protect to protect. Five is a constitution the acmodation is in the concrete structure of the constringency sew. The Su constringency crack and prevention Su constringency is the concrete is before condense, surface because of lose water quicker but creation of constringency. The Su constringency crack is general at dry heat or strong wind the weather appear, crack39。In mon use rigid water material is the polymer cement sand syrup. The structure reinforce a method When the crack influence arrive concrete structure of function, will consideration adopt to reinforce a method to carry on processing to the concrete structure reinforce medium in mon use main have the following a few method:The piece of enlargement concrete structure in every aspect accumulate, outside the Cape department of the Gou piece 浙江大學(xué)城市學(xué)院畢業(yè)設(shè)計(jì) 外文翻譯 pack type steel, adoption prepare should the dint method reinforce, glue to stick steel plate to reinforce, increase to establish fulcrum to reinforce and jet the concrete pensation reinforce. Concrete displacement method Concrete displacement method is processing severity damage concrete of a kind of valid method, this method be first will damage of the concrete pick and get rid of, then again displacement go into new of concrete or other in mon use displacement material have:Common concrete or the cement sand syrup, polymer or change sex polymer concrete or sand syrup. The electricity chemistry protection method The electricity chemistry antisepsis is to make use of infliction electric field in lie the quality of electricity chemical effect, change concrete or reinforced concrete the environment appearance of the place, the bluntness turn reinforcing bar to attain the purpose of protection method, chlorine salt39。Have outside carry the crack that the function cause。在寒冷季節(jié)，混凝土表面應(yīng)設(shè)置保溫措施，以防止寒潮襲擊。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。此類裂縫多為深進(jìn)或貫穿性裂縫，其走向與沉陷情況有關(guān)，一般沿與地面垂直或呈 30176。 主要預(yù)防措施：一是選用收縮量較小的水泥，一般 多采用中低熱水泥和粉煤灰水泥，降低水泥的用量。微裂縫通常是一種無害裂縫，對(duì)混凝土的承重、 抗?jié)B透 及其他一些使用功能不產(chǎn)生危害。 混凝土工程中常見裂縫及預(yù)防 干縮裂縫及預(yù)防 浙江大學(xué)城市學(xué)院畢業(yè)設(shè)計(jì) 外文翻譯 干縮裂縫 通常 出現(xiàn)在混凝土養(yǎng)護(hù)結(jié)束后的一段時(shí)間或是混凝土澆筑完 畢后的一周左右。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(jié)時(shí)間、環(huán)境溫度、風(fēng)速、相對(duì)濕度等等。五是在凍土上搭設(shè)模板時(shí)要注意采取一定的預(yù)防措施。七是高溫季節(jié)澆筑時(shí)可以采用搭設(shè)遮陽板等輔助措施控制混凝土的溫升，降低澆筑混凝土的溫度。通常的預(yù)防措施有：一是保證鋼筋保護(hù)層的厚度。 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。三是混凝土澆注要振搗密實(shí)。九是在大體積混凝土內(nèi)部設(shè)置冷卻管道，通冷水或者冷氣冷卻，減小混凝土的內(nèi)外溫差?；炷翝仓?以 后，在硬化 的 過程中，水泥水化 所 產(chǎn)生大量的水化熱，（當(dāng)水泥用量在 350550 kg/m3，每立方米混凝土將釋放出 1750027500kJ 的熱量，從而使混凝土內(nèi)部溫度升達(dá)70℃左右甚至更高）。二是嚴(yán)格控制水灰比，摻入高效減水劑來增加混凝土的坍落度與 和易性，減少水泥及浙江大學(xué)城市學(xué)院畢業(yè)設(shè)計(jì) 外文翻譯 水的用量。干縮裂縫的產(chǎn)生主要是由于混凝土內(nèi)外 層混凝土水分蒸發(fā)程度不同而導(dǎo)致的變形不同 ：混凝土受外部條件的影響，表面水分 蒸發(fā) 過 快，變形較大，內(nèi)部 水分蒸發(fā)滿 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(nèi)部 較小 約束， 因 產(chǎn)生較大拉應(yīng)力而 連帶產(chǎn)生裂縫。 關(guān)鍵詞： 混凝土 ， 裂縫 ， 預(yù)防 ， 處理 前言 混凝土是一種由砂石骨料、水泥、水及其 他多種材料混合而形成的脆性材料。干縮裂縫 的存在 通常會(huì)影響混凝土的抗?jié)B 透 性 能 ，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 性能 等等。五是在高溫和大風(fēng)天氣要設(shè)置遮陽和擋風(fēng)設(shè)施， 并 及時(shí) 進(jìn)行 養(yǎng)護(hù)。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。十二是減小約束，澆筑混凝土前宜在基巖和老混凝土上鋪設(shè) 5mm 左右的砂墊層或使用瀝青等材料涂刷。s life and property safety. A lot of all of crash of engineerings is because of the unsteady development of the crack with the result that. Modern 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。s anticipating the crack that reaction 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. The concrete blend a future reunion creation so