預(yù)應(yīng)力混凝土的廣泛應(yīng)用外文翻譯-預(yù)覽頁(yè)
【正文】 ions to improve still further fracture, cracking there until the late 1980s, began to be recognized and confirmed by the pilot. Inspection process is: first concrete sleeper in the coresample, the test items, including: ① the naked eye or using threedimensional microscope, and then sidethin reflective microscope, the damage caused by the general AAR regular injury aggregate particles, the more cracks from the aggregate Extending to the slurry, and sometimes also obvious observation aggregate stars expected to split or torn edges. This feature is very important, because of salt corrosion, chemical corrosion, steel corrosion, carbonate, such as mechanical load will not make aggregate particles by injury, so this is AAR and other factors undermining the main features。 ② end of the fracture or cracking of the sleeper, static cracking strength And fatigue, pared with the normal sleeper, in general there was no significant difference. This shows that the end of the rail fracture and multiple cracks from the surface, not to influence the development of concrete and steel of the Bonding. 3. concrete sleeper cracks in the prevention and control Sleeper as a priestess’s concrete structure, in order to pletely eliminate cracks is very difficult to do. After all, but the crack is harmful. For this reason, every effort should be made to prevent the emergence of crack. Prevention and control of cracks, you can start with a threepronged: 西南交通 大學(xué)本科 畢業(yè)設(shè)計(jì) 第 5 頁(yè) First, from the mechanical point of view, in order to prevent horizontal cracks, except in accordance with the greatest possible load, the rational allocation of priestesses reinforced, we must also strengthen the end of the stirrups and the spiral reinforcement clip bolt whole configuration. In addition, to strengthen the conservation line maintenance so that the sleeper is in a good state support under the track and prevent the sleeper pillow horizontal cracks appeared in the major conditions. Stirrups and spiral reinforcement of the settings and prevent sleeper End and central fracture cracks and nail holes, but not the overall stirrups itself, and is reinforced and priestesses loose lap, in the prevention of fracture in a limited effect. Some factories will be strictly end of the stirrups layout from the end of the first 30 mm, and priestesses reinforced Bingham firmly together, thus found to prevent the end of the fracture have a good effect. Second, to strengthen production management and operation After the 1990s, China39。當(dāng)元件用來(lái)承受的負(fù)荷和壓力，首先要抵消預(yù)應(yīng)力混凝土，然后隨著負(fù)載的增加，混凝土產(chǎn)生應(yīng)力拉 伸 區(qū)。但是，為了 換 新的軌枕，除了重新 制造 ，而且還需要 處理，運(yùn)輸和 安裝到線(xiàn)路上 ，不僅需要花費(fèi)大量的人力和物力，有時(shí)對(duì)交通的影響，成本往往是軌枕本身的費(fèi)用 4 至 5 倍。 機(jī)械因素 混凝土軌枕不僅時(shí)刻遭受動(dòng)態(tài)壓力，而且 軌枕的端部有關(guān) 。和一般 混凝土軌枕 從具體產(chǎn)品與不同國(guó)家支持的軌枕車(chē)的運(yùn)作和維修的條件不斷變化，曾經(jīng)支持國(guó)家和動(dòng)壓震垂直懸掛由合并后的影響而產(chǎn)生超過(guò)設(shè)計(jì)極限，目前，相應(yīng)的部分軌枕將有一個(gè)裂縫。 一段時(shí)間以來(lái)，許多工廠軌枕 在 蒸汽養(yǎng)護(hù) 期 間沒(méi)有預(yù)留停留 時(shí)間，升溫快，恒溫器溫度高于 95℃ ，在混凝土軌枕 底部 剝離腫脹， 松 散的情況常常發(fā)生。其中最常見(jiàn)的基地 硅酸反應(yīng)。這個(gè)問(wèn)題從 60 年代末，一個(gè)預(yù)應(yīng)力混凝土的混凝土軌枕（橋梁）發(fā)生 多次打擊骨裂 ， 由于 廠生產(chǎn)，加工，鋪設(shè)保護(hù)條件 不足 ，進(jìn)一步提高斷裂，開(kāi)裂，直到， 80年代后期有開(kāi)始我們必須承認(rèn)和肯定了試點(diǎn)。 總之， 縱向裂縫是由于內(nèi)部因素 （材料，結(jié)構(gòu)，技術(shù)因素） ，外部因素 （加載和凍融，干濕循環(huán)）只有促進(jìn)其發(fā)展，橫向裂縫是內(nèi)部（預(yù)應(yīng)力混凝土 鋼筋 ，混凝土強(qiáng)度）和（ 加載 和軌枕邊界條件），外部因素組合造成的。然而，很多時(shí)候 在國(guó)內(nèi)和國(guó)外的調(diào)查 和試驗(yàn) ， 關(guān)系到 裂縫寬度 而 不是直接關(guān)系到鋼鐵的腐蝕。從測(cè)試結(jié)果可以看出： ① 通過(guò)在軌枕裂縫，對(duì)鐵路的一段最靜載荷下裂強(qiáng)度明顯降低 。基于這個(gè)原因，應(yīng)作出一切努力，防止裂縫的出現(xiàn)。一些工廠將嚴(yán)格的箍筋最后，從最終的布局前 30 毫米，預(yù)應(yīng)力鋼筋固在一起，從而 對(duì) 防止 斷裂 有很好的 影響 。這些措施，是 以減少軌枕裂縫，裂縫和斷裂，特別是將是非常有益的。 總之，在早期養(yǎng)護(hù)混凝土，主要目的是保持適當(dāng)?shù)臏囟群蜐穸葪l件，以實(shí)現(xiàn)雙方的影響，一方面，從不利的溫度和濕度的侵襲變形混凝土，以防止有害倦怠和收縮。
畢業(yè)設(shè)計(jì)相關(guān)推薦
鄂ICP備17016276號(hào)-1