Question

翻译中文到英文

混凝土结构在其服务使用期间应维持所需的强度和其他功能,混凝土结构还必须能经受住各种各样的侵蚀破坏,这常被称为混凝土具有耐久性。但是耐久性并不是指混凝土的使用期间为无限长,也不是指混凝土能抵御各种破坏作用。日常的维护对混凝土的耐久性有着重要的影响。由于混凝土结构的强度得到逐渐提高,混凝土的耐久性可能也会被认为是自然的得到改善。但事实上,强度和耐久性是两个不同的概念,反映了混凝土性能的不同方面。对于大多数混凝土结构,强度和耐久性都应在设计阶段得到考虑,有时耐久性还成为更主要的设计参数。
　　2.1 混凝土的渗透性
　　在混凝土中,渗透性是一个重要指标,它是指气体、液体或者离子受压力、化学势或者电场作用,在混凝土中渗透、扩散或者迁移的难易程度。混凝土产生渗透的主要原因是混凝土中存在大量孔隙和裂缝。混凝土的孔结构包括水泥石浆体孔隙、集料中的孔隙、集料和将题解免检的孔隙等,施工不良也会导致部分蜂窝结构。
　　由于混凝土的渗透性决定了气体、液体以及可溶性有害物质侵入混凝土的难易程度,直接影响着混凝土的碳化、侵蚀、钢筋锈蚀和抗冻融能力,所以是影响混凝土建筑耐久性最重要的因素之一,混凝土的耐久性可以通过渗透性来评价。
　　2.2 混凝土的碱-集料反应
　　碱集料反应是指混凝土原材料(包括水泥、骨料、外加剂、混合料及拌和水等)中的碱性物质与活性成分发生化学反应,生成膨胀物质(或吸水膨胀物质)而引起混凝土产生内部自膨胀应力而开裂的现象。由于碱集料反应一般是在混凝土成型后的若干年后逐渐发生,其结果造成混凝土耐久性下降,严重时还会使混凝土丧失使用价值,且由于反应是发生在整个混凝土中,因此,这种反应造成的破坏既难以预防,又难于阻止,更不易修补和挽救,故被成为混凝土的癌症。
　　2.3 混凝土的氯离子侵蚀
　　氯盐是一种最有害的侵蚀性化合物,能导致混凝土迅速被侵蚀损坏。由于浆体孔液的性质,混凝土基体表现为强碱性。浆体孔液中含有大量的碱,其pH只可达13。但是氯盐溶液具有较强的酸性和侵蚀性,侵蚀作用的强度则取决于氯盐溶液浓度以及与氯离子结合的阳离子的种类。氯盐的侵蚀过程需要氯离子侵入到混凝土微结构中,并需要从析出的水泥水化相中有反向离子的移动。因此混凝土的孔结构和渗透性对于氯离子侵蚀有非常重要的影响。氯离子侵蚀对于水泥混凝土路面及桥梁板面有明显的损坏作用,这包括采用除冰剂后混凝土表面产生的剥落损坏以及内部钢筋的锈蚀。
　　2.4 混凝土的硫酸盐侵蚀
　　自然界存在各种硫酸盐,并且硫酸盐在工业生产中也得到光反射采用。硫酸盐溶液会与混凝土结构接触或是进入到混凝土基体中,并与水泥水化产物反应,导致混凝土的膨胀、开裂、剥落等损坏,进而使混凝土结构失去完整性和稳定性。
　　硫酸盐作用下混凝土宏观性能的劣化主要是由于侵蚀过程中新相的生成和旧相的消失等微观结构的改变所导致的,因此,通过XRD等微观手段分析侵蚀产物以探究硫酸盐侵蚀机理并解释其宏观上的性能劣化原因对于评价方法的研究具有重要的指导意义。

　3.1 原材料的选择
　　水泥类材料的强度和工程性能,是通过水泥砂浆的凝结,硬化形成的,水泥石一旦受损,混凝土的耐久性就被破坏,因此水泥的选择需注意水泥品种的具体性能,选择碱含量小,水化热低,干缩性小,耐热性,抗水性,抗腐蚀性,抗冻性能好的水泥,并结合具体情况进行选择。水泥强度并非是决定混凝土强度和性能的唯一标准,如用较低标号水泥同样可以配制高标号混凝土。因此,工程中选择水泥强度的同时,需考虑其工程性能,有时,其工程性能比强度更重要。

Answer 1

　　During the life of concrete structure in its service should keep the required strength, and other functions, concrete structure also must be able to withstand all kinds of erosion damage, this is often referred to as the concrete durability. But I wasn't referring to concrete durability during the use of for the infinite long, also is not a concrete can resist all kinds of damage. Daily maintenance has an important influence on the durability of concrete. Due to the strength of the concrete structure is increased gradually, the durability of concrete may also be considered to be naturally improve. But, in fact, strength and durability are two different concepts, reflect the different aspects of concrete performance. For the majority of concrete structure, strength and durability should be considered during the design phase, sometimes the durability has become main design parameters.
　　2.1 the permeability of concrete
　　In concrete, the permeability is an important indicator, it refers to gas, liquid pressure or ions, the chemical potential or electric fields, in the concrete to the difficulty of the infiltration, proliferation or migration. Concrete permeability is the main reason of the concrete in a large number of pore and fracture. The pore structure of concrete including cement paste pore, pore in the aggregate, aggregate and will be exempted from inspection as antithesis pore, poor construction can also lead to parts of honeycomb structure.
　　Due to the permeability of concrete determines the gas, liquid and the ease of soluble hazardous substances into concrete, a direct impact on the carbonation of concrete steel corrosion, erosion, and the freezing-thawing resisting ability, so it is one of the most important factors that affect the durability of concrete structures, the durability of concrete permeability to evaluation.
　　2.2 concrete alkali aggregate reaction
　　JianJiLiao response refers to the concrete raw materials (including cement, aggregate, admixtures and mixing and mixing water, etc.) in the alkaline substances react with the active ingredient, generate expansive material (material) or swell caused by concrete inside the expansion stress and cracking phenomenon. With general JianJiLiao response is after some years after the concrete forming gradually, the results cause the loss of concrete durability, serious when still can make concrete lost use value, and the reaction is occurred in the concrete, therefore, the damage caused by this reaction are difficult to prevent, and difficult to prevent, more is not easy to repair and saving, so called the concrete cancer.
　　2.3 concrete chloride ion erosion
　　Chlorine salt compounds is one of the most harmful erosion sex, can lead to damage of concrete rapidly eroded. Due to the slurry properties of pore fluid, the concrete substrate characterized by strong alkali. Slurry hole fluid contains large amounts of alkali, its pH may only 13. But chlorine salt solution with strong acidity and erosion resistance, erosion intensity depends on chlorine salt solution concentration and combine with chlorine ion of cationic species. The chlorine salt erosion process need to chloride ion penetration into concrete microstructure, and require the precipitation from the cement hydration phase has a reverse movement of ions. Therefore the pore structure and permeability of concrete to chloride ion erosion has very important influence. The chloride ion erosion for cement concrete pavement and bridge panel has obvious damage effect, including the use of deicing agent after spalling of concrete surface damage and corrosion of the internal reinforcement.
　　2.4 the sulfate attack of concrete
　　Nature exist all sorts of sulfate and sulfate in the industrial production has also been used light reflex. Sulfate solution will be in contact with the concrete structure or into the concrete matrix, and the cement hydration reaction product, lead to the expansion of the concrete, cracking and spalling damage, and then lose concrete structure integrity and stability.
　　Concrete under sulfate macro performance degradation is due to the formation of new phase in the process of erosion and the disappearance of the old phase microstructure change as a result of, therefore, through the microscopic methods such as XRD analysis of corrosion products to explore the mechanism of sulfate erosion and the performance degradation of macro explain the reason for evaluation method research has important guiding significance.
　　3.1 the choice of raw materials
　　The strength of the cement materials and engineering properties, it is through the condensation of cement mortar, hardening of formation, cement stone once damaged, the durability of concrete were damaged, so the cement should pay attention to the choice of varieties of cement concrete performance, select small alkali content, low hydration heat, dry shrinkage of small, heat resistance, water resistance, corrosion resistance, good cement antifreeze performance, combined with the specific situation to choose. Cement strength are not the only standard to concrete strength and performance, such as low grade cement can also make high grade concrete. Choose the cement strength at the same time, therefore, the project should be considered its engineering properties, sometimes, its engineering properties are more important than strength.