外文翻譯--再生改性混凝土的性能

中文 3074 字 畢業(yè)設(shè)計(jì) (論文 )外文資料翻譯 系 別： 建筑工程系 專 業(yè)： 土木工程 班 級(jí)： 姓 名： 學(xué) 號(hào)： 外文出處： 漢斯國(guó)際期刊土木欄 附 件： 1. 原文 ； 2. 譯文 2013 年 12 月 29 日 原 文 ： The Regeneration Performance of Modified Concrete Abstract: the removal of the original building, to make use of the abandoned concrete, can Protect environment and related to the sustainable development of building. The waste concrete crushing recycled aggregate, need to establish a process. Currently relatively mature methods are: the use of swelling shrinkage compensating admixture can be made from recycled concrete C50. Keywords: ecological environment; recycled aggregate; basic properties; shrinkage compensation 1 Introduction In todays world, environmental problems have become increasingly prominent, the sustainable development has been put on the agenda. Efficient, rational use of limited resources is the most important way to achieve sustainable development. Concrete production requires a large amount of coarse and fine aggregate and sand, with the continuous mining of sand, natural building aggregate tends to dry up, the high cost of mining, the damage to the ecological environment is also very serious. On the other hand, the rapid development of city construction and all kinds of natural disasters have abandoned concrete waste a lot of. Recycling with the strategy of sustainable development requirements of the waste concrete, can bring significant social, economic and environmental benefits, the rise of the recycled concrete has become an important research topic in many developed countries. 2 International renewable development status of concrete The waste concrete block by crushing, grading and mixing according to certain proportion to form aggregates known as recycled aggregate and recycled concrete aggregate. As a part or the whole of the recycled aggregate concrete as recycled aggregate concrete, recycled concrete, the traditional building materials production and use caused by excessive consumption of resources, energy shortages and environmental pollution and other serious problems, cement and concrete is an important cause of these problems. Cement concrete structure is usually only a few decades of life cycle, completed in the structure of its use, the old concrete will be abandoned. According to statistics, industrial solid wastes produced 40% is the construction industry, construction industry to produce waste concrete is the biggest waste. In twentieth Century 90 in the early 1990s, the national annual output of waste concrete is 50000000 tons, USA is 60000000 tons, about 12000000 tons of Japan. Facing the increasing shortage of sand and other natural resources, the grim situation of construction waste is increasing, governments and research institutions have established policies, the development of new technology, in order to promote the construction waste especially recycling old concrete utilization. According to statistics, since the 90s, the annual consumption of the world total has more than 80 tones of concrete. In concrete aggregate accounted for over 70% of the total mass. 3 Compensating shrinkage of modified concrete Normal concrete is to use a wide range of building materials, but because of its limit extension rate is low, easy to crack in the dry shrinkage, creep, temperature effect, resulting in leakage caused by corrosion of reinforcement and concrete engineering, use function and the life of structures. The research indicated that, the swelling agent or expansion of shrinkage compensating concrete cement, concrete cracking is to solve the effective technical way infiltration problem because of shrinkage compensating concrete hardening process in water can produce 0.20.7 Map pre compressive stress (or stress), the stress can be offset or partially offset by concrete shrinkage, creep, temperature induced tensile stress, so as to improve crack resistance of concrete engineering; in addition, due to the hydration expansion hole filling effect of products, the large hole in cement paste is smaller, the total porosity, which can improve the pore structure of concrete, greatly improve the impermeability of concrete, therefore make shrinkage compensating concrete expansive cement in foreign countries is also known as the waterproof cement. The shrinkage compensating concrete is an important branch of modern concrete science, its unique properties, is to solve the volume stability, high performance concrete is an important technical basis to improve the durability of concrete, the research on it has yet to be further and perfect, this paper expounds some basic properties of shrinkage compensating concrete. 3.1 Expansion agent Physical and chemical properties: refers to the concrete expansion agent in concrete mixing process and the cement, water mixing after hydration reaction of stringier 3CaO Al2O3 3CaSO4 32H2O or calcium hydroxide Ca (OH) 2, make concrete produce volume expansion admixture. Concrete expansion agent is used to prepare the expansive concrete (including shrinkage compensating concrete and self stressing concrete), shrinkage compensating concrete shrinkage and compacting concrete with, improve concrete anti permeability role compensation concrete, in civil engineering in two aspects mainly used for waterproofing and anti cracking, now use more occasions is preparation of high grade waterproof concrete and appropriate to extend the expansion joint or post cast band spacing. 4 Basic properties of shrinkage compensating concrete 4.1 Material 4.1.1 Concrete before hardening Agent content and fresh initial concrete slump expansion: expansion agent effect on the initial slump of fresh concrete degree, largely depends on the expansion agent fineness, when the expansion and cement fineness difference, mixing water demand is basically the same, almost has no effect on the initial slump. 4.1.2 Setting time Effect of expansive agent on setting time of concrete expansion admixture added: no matter what, will make the concrete setting time, expansion admixture amount bigger, the setting time is fast, doping agent will have the same results with and without the addition. 4.1.3 Curing conditions Compared with ordinary concrete, shrinkage compensating concrete need more water conservation fully, because the water is the essential factors of expansion, long in the water curing of concrete can obtain the biggest expansion. Expansive concrete to dry air (RH = 60 5%) curing shrinkage, too, but then return maintenance, and can restore the previous expansion. 4.1.4 Drying shrinkage As with ordinary concrete, shrinkage compensating concrete will also occur in air drying shrinkage, factors affecting the drying shrinkage of concrete with ordinary roughly the same, but the relative humidity of the external factors, internal factors of water binder ratio is more important. Under the same conditions, drying shrinkage fall of shrinkage compensating concrete and common concrete in roughly the same. 4.2 Recycled concrete Strength with the matrix concrete of recycled concrete strength, regeneration substitution rate and recycled concrete mixture ratio is closely related to aggregate crushing technology, recycled aggregate. Due to the strength of concrete, the matrix using environment and carbonization degree each are not identical, differences of disintegration, crushing process and quality control measures, resulting in regular changes of concrete strength regeneration is poor, different researchers have different conclusions. Test results show that: 1) the compressive strength of recycled concrete is lower than the compressive strength of natural aggregate concrete ratio, reduce the range of 0%30%. Improve and strength of recycled aggregate concrete with strength of recycled aggregate concrete matrix increased; and with the increase of recycled aggregate replacement rate decreased, when the recycled aggregate replacement rate is less than 30%, the recycled concrete strength decreases little; recycled concrete replaced natural coarse aggregate with recycled coarse aggregate strength decreased less, and regeneration concrete recycled fine aggregate instead of natural fine aggregate strength decreased obviously, the age showed the same trend; the water cement ratio of recycled concrete strength with great effect, reducing the water cement ratio, with the natural aggregate concrete strength contrast, more and more small to reduce the strength of recycled concrete. For the recycled concrete with different strength grade, the origin and nature of the influence of recycled aggregate on the strength degree is different: preparation of high strength recycled aggregate concrete, influence on strength of recycled aggregate concrete sources and properties of recycled aggregate; recycled aggregate medium strength concrete, the strength of recycled aggregate concrete and influence; 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 0.180.23. 3) compared 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 penetrate 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 compensating 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 compensating concrete anti cracking performance is excellent, and is an ideal concrete structure from waterproof materials, shrinkage compensating concrete underground buildings, can be completely canceled waterproof, not only shorten the construction period, but also save the engineering cost, waterproof life and buildings. In recent years, the rapid development of concrete technology, especially the application of high performance concrete is becoming more and more widely, put forward higher requirements on the shrinkage compensating concrete shrinkage compensation theory, the urgent need to have the new breakthrough, instructional materials, design, construction and inspection method innovation. Can be expected in a fairly long period of time, the technical field of concrete may not be new technology to replace the shrinkage compensating concrete, so in order to improve the performance of shrinkage compensating concrete cracks, relief has broad prospects for development, but the need to keep pace with the times, innovation. 譯文 ： 再生改性混凝土的性能 摘 要 ：拆除原有的建筑物，對(duì)廢棄的混凝土加以利用，既可以保護(hù)環(huán)境又關(guān)系到建筑的可持續(xù)發(fā)展。將廢棄的混凝土破碎再生骨料，需要建立一套工藝方法?，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。 關(guān)鍵詞 ：生態(tài)環(huán)境；再生骨料；基本性能；補(bǔ)償收縮 1 引言 當(dāng)今世界，環(huán)境問(wèn)題日益凸顯，可持續(xù)發(fā)展被提上日程。有效、合理地利用有限的資源是實(shí)現(xiàn)可持續(xù)發(fā)展的首要途徑?；炷辽a(chǎn)需要大量的粗細(xì)骨料 砂石，隨著對(duì)砂石的不斷開采，天然建筑骨料趨于枯竭，開采成本高，對(duì)生態(tài)環(huán)境的 破壞也十分嚴(yán)重。另一方面，城市建筑業(yè)的迅速發(fā)展以及各種自然災(zāi)害產(chǎn)生了大量的廢棄混凝土垃圾。對(duì)這些廢舊混凝土進(jìn)行回收利用符合可持續(xù)發(fā)展戰(zhàn)略的要求，能帶來(lái)顯著的社會(huì)、經(jīng)濟(jì)和環(huán)境效益，由此興起的再生混凝土技術(shù)已成為許多發(fā)達(dá)國(guó)家的重要研究課題。 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 。 利用再生骨料作為部分或全部骨料配制的混凝土稱為再生骨料混凝土 ， 簡(jiǎn)稱再生混凝土 ， 傳統(tǒng)的建筑材料生產(chǎn)和使用造成資源的過(guò)度消耗、能源短缺和環(huán)境污染等嚴(yán)重的問(wèn)題，水泥 和混凝土是導(dǎo)致這些問(wèn)題的重要原因。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。據(jù)統(tǒng)計(jì)，工業(yè)固體廢棄物中 40%是建筑業(yè)產(chǎn)生的，廢棄混凝土是建筑業(yè)制造出的最大的廢棄物。 20世紀(jì) 90年代初，歐共體國(guó)家每年產(chǎn)出廢棄混凝土為 5000萬(wàn)噸，美國(guó)為 6000萬(wàn)噸，日本約 1200萬(wàn)噸。面對(duì)砂石等自然資源日益短缺，而建筑廢棄物日漸增加的嚴(yán)峻形勢(shì)，各國(guó)政府和研究機(jī)構(gòu)紛紛制定政策，發(fā)展新技術(shù)，以促進(jìn)建筑廢棄物尤其是舊混凝土的再生利用。據(jù)統(tǒng)計(jì)，90 年代以來(lái)，每年全世界總體混凝土的消費(fèi)量己 超過(guò) 80億噸。而混凝土中砂石骨料占總質(zhì)量的 70%以上。 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。國(guó)內(nèi)外的研究表明，采用膨脹劑或膨脹水泥配制的補(bǔ)償收縮混凝土，是解決混凝土材料裂滲問(wèn)題的有效技術(shù)途徑這是因?yàn)檠a(bǔ)償收縮混凝土在水化硬化過(guò)程中能夠產(chǎn)生 0.20.7 MPa預(yù)壓應(yīng)力 (即自應(yīng)力 )，該應(yīng)力能抵消或部分抵消由混凝土干縮、徐變、溫度等引起的拉應(yīng)力，從而提高混凝土工程 的抗裂性能；另外，由于水化膨脹產(chǎn)物的填孔作用，使水泥石中的大孔變小，總孔隙率減小，從而改善了混凝土的孔結(jié)構(gòu)，大幅度提高了混凝土的抗?jié)B性能，因此配制補(bǔ)償收縮混凝土的膨脹水泥在國(guó)外又稱為“不透水水泥”。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。 3.1 膨脹劑 物理化學(xué)性能：混凝土膨脹劑是指其在混凝土拌制過(guò)程中與水泥、水拌和后經(jīng)水化反應(yīng)生成鈣礬石 3CaO Al2O3 3CaSO4 32H2O或氫氧化鈣 Ca(OH)2，使混凝土產(chǎn)生體積膨脹的外加劑?；炷僚蛎泟┲饕脕?lái)配制膨脹混凝土 (包括補(bǔ)償收縮混凝土和自應(yīng)力混凝土 )，補(bǔ)償收縮混凝土具有補(bǔ)償混凝土干縮和密實(shí)混凝土、提高混凝土抗?jié)B性作用，在土木工程中主要用于防水和抗裂兩個(gè)方面，現(xiàn)在使用較多的場(chǎng)合是配制高等級(jí)防水混凝土和適當(dāng)延長(zhǎng)伸縮縫或后澆帶間距。 4 補(bǔ)償收縮改性混凝土的基本性能 4.1 材料性能 4.1.1 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。 4.1.2 凝結(jié)時(shí)間 膨脹劑對(duì)混凝土凝結(jié)時(shí)間的影響：無(wú)論摻加何種膨脹劑，都會(huì)使混凝土凝結(jié)時(shí)間提前，膨脹劑摻量越大，凝結(jié)時(shí)間越快，摻與不摻減水劑都有相同的結(jié)果。 4.1.3 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)