外文翻譯--再生改性混凝土的性能(存儲(chǔ)版)
【正文】 Expansive concrete to dry air (RH = 60 177?，F(xiàn)就目前比較成熟的方法是：使用膨脹劑能夠制成 C50的補(bǔ)償收縮再生混凝土。水泥混凝土結(jié)構(gòu)通常只有幾十年的生命周期，在這些結(jié)構(gòu)完成其使用功能后，舊混凝土就會(huì)被廢棄。補(bǔ)償收縮混凝土是現(xiàn)代混凝土科學(xué)的一個(gè)重要分支，其性能獨(dú)特，是解決高性能混凝土體積穩(wěn)定性、提高混凝土耐久性的一個(gè)重要技術(shù)基礎(chǔ)，對(duì)它的研究還有待進(jìn)一步深入和完善，本文綜合闡述了補(bǔ)償收縮改性混凝土的一些基本性能。 養(yǎng)護(hù)條件的影響 與普通混凝土相比，補(bǔ)償收縮混凝土更需要充分的水養(yǎng)護(hù)，因?yàn)樗质瞧洚a(chǎn)生膨脹的必要因素，長(zhǎng)期在水中養(yǎng)護(hù)的混凝土能夠獲得最大的膨脹。而且再生混凝土的強(qiáng)度隨再生骨料的基體混凝土強(qiáng)度的提高而上升；并隨再生骨料摻量的增加而降低，當(dāng)再生骨料的取代率小于 30%時(shí)，再生混凝土強(qiáng)度降低很少；用再生粗骨料取代天然粗骨料的再生混凝土的強(qiáng)度降低幅度較小，而用再生細(xì)骨料取代天然細(xì)骨料的再生混凝土的強(qiáng)度有較明顯的下降，各齡期均表 現(xiàn)出相同的趨勢(shì)；水灰比對(duì)再生混凝土強(qiáng)度的影響較大，隨著水灰比的減小，與天然骨料混凝土強(qiáng)度對(duì)比，再生混凝土強(qiáng)度降低的幅度越來(lái)越小。但如采 用較低水灰比或較高強(qiáng)度的再生骨料，試驗(yàn)結(jié)果顯示，可以降低再生混凝土的干縮和徐變。 。干縮的增大取決于基體混凝土的性能、再生骨料質(zhì)量以及再生混凝土的配合比。由于基體混凝土的強(qiáng)度等級(jí)、使用環(huán)境 與碳化程度各不相同，解體、破碎的工藝及質(zhì)量控制措施的差異，導(dǎo)致再生混凝土強(qiáng)度變化的規(guī)律性較差，不同的研究者所得的結(jié)論也有所不同。 4 補(bǔ)償收縮改性混凝土的基本性能 材料性能 混凝土硬化前的性質(zhì) 膨脹劑摻量與新拌混凝土初始坍落度的關(guān)系：膨脹劑對(duì)新拌混凝土初始坍落度的影響，很大程度上決定于膨脹劑的細(xì)度，當(dāng)膨脹劑的細(xì)度與水泥相差不大 時(shí)，拌合需水量也基本相同，對(duì)初始坍落度基本沒(méi)有影響。 3 補(bǔ)償收縮改性混凝土的組成 普通混凝土是用途極廣的建筑材料，但是由于它的極限延伸率較低，在干縮、徐變、溫度等作用下容 易開(kāi)裂， 導(dǎo)致混凝土工程滲漏并引發(fā)鋼筋銹蝕，影響構(gòu)筑物的使用功能和壽命。 2 國(guó)際上 再生混凝土發(fā)展?fàn)顩r 將廢棄混凝土塊經(jīng)破碎、分級(jí)并按一定的比例混合后形成的骨料稱為再生骨料或再生混凝土骨料 。 preparation of recycled aggregate concrete with low intensity, the regeneration effect of mixed coagulation on the strength is very small. 2) because of recycled aggregate adsorption with lots of old mortar, resulting in elastic modulus of recycled aggregate concrete is usually low, generally for natural aggregate concrete 70%~80%, reduce the average 25%. The elastic modulus of recycled aggregate concrete is lower, resulting in lower brittleness, toughness increased, the seismic performance of recycled concrete structure is favorable, and enhance the ability to resist dynamic loads. Poisson recycled concrete is usually in the range of ~. 3) pared to recycled concrete and natural aggregate concrete, the dry shrinkage and creep increased by an average of about 60%. Dry shrinkage increases depends on the matrix properties of concrete, recycled aggregate and recycled concrete than with the quality. Have a certain influence the popularization and application of shrinkage and CSU Biennia Conference on recycled concrete, this will make the recycled concrete structure produce more non loading cracks, if cracks through the inside and outside environment, water and other harmful substances can easily perate into concrete, is disadvantageous to the durability of structures. But such as the use of recycled aggregate is low water cement ratio and high strength, test results show, can reduce the recycled concrete shrinkage and creep. Therefore, for the promotion of recycled concrete, it can be used in structural concrete, need further study to improve the strength of recycled concrete way, reducing shrinkage and creep method of recycled concrete, micro structure and failure mechanism of recycled concrete. 5 Conclusion Expansive cement invention has been 70 years of history, the history of the application of shrinkage pensating concrete is also 50 years, from the day of its birth, its location is a kind of special concrete anti seepage, and formed a set of more perfect theory system. Engineering practice that, the shrinkage pensating concrete anti cracking performance is excellent, and is an ideal c
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