【正文】
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 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 interleave。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 B 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。四是鋼筋表層涂刷防腐涂料。 由于混凝土澆筑、振搗不良或者是鋼筋保護(hù)層較薄,有害物質(zhì)進(jìn)入混凝土使鋼筋產(chǎn)生銹蝕,銹蝕的鋼筋體積膨脹,導(dǎo)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)。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。高溫膨脹引起的混凝土溫度裂縫是通常中間粗兩端細(xì),而冷縮裂縫的粗細(xì)變化不太明顯。當(dāng)拉應(yīng)力超過混凝土的抗拉強(qiáng)度極限時,混凝土表面就會產(chǎn)生裂縫,這種裂縫多發(fā)生在混凝土施工中后期。地基變形穩(wěn)定之后,沉陷裂縫也基本趨于穩(wěn)定。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。塑性收縮裂縫一般在干熱或大風(fēng)天氣出現(xiàn),裂縫多呈中間寬、兩端細(xì)且長短不一,互不連貫狀態(tài)。干縮裂縫多為表面性的平行線狀或網(wǎng)狀淺細(xì)裂縫,寬度多在 ,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。 1 畢業(yè)英語翻譯