Durability of concrete 混凝土的耐久性.pptVIP

Durability of concrete 混凝土的耐久性 08工程管理（1）班 李海姣、纪飞、刘涛、林新、王腾 Besides its ability to sustain loads, concrete is also required to be durable. durable [dju?r?bl] 耐久的 混凝土除了承受荷载之外，还需要有一定的耐久性。 The durability of concrete can be defined as its resistance to deterioration (resulting from external and internal causes). durability：耐久性；deterioration :恶化，劣化; 混凝土的耐久性可能被定义为混凝土对于内外原因引起的劣化的抵抗能力。 The external causes include the effects of environmental and service conditions (to which concrete is subjected), such as weathering, chemical actions and wear. be subjected to受到…； weathering风化；wear：磨损. 外部原因包括混凝土受环境和使用条件的影响，如风化，化学作用和磨损。 The internal causes are the effects of salts, particularly chlorides and sulphates, in the constituent materials, interaction between the constituent materials, such as alkali aggregate reaction, volume changes, absorption and permeability. chlorides:氯盐; sulphates:硫酸盐; alkali aggregate reaction:碱骨料反应; absorption:吸收; permeability：渗透性。 内部原因是组成材料中的盐，特别是氯盐和硫酸盐，与组成材料之间的相互作用，如碱骨料反应，体积变化，吸收和渗透性。 In order to produce a durable concrete care should be taken to select suitable constituent materials. 为了生产具有耐久性的混凝土，应注意选择合适的组成材料。 It is also important that the mix contains adequate quantities of materials in proportions suitable for producing a homogeneous and fully compacted concrete mass. homogeneous：均匀的； compacted：压实的； mass：大规模的，块。 混合物中包含充足的按比例配置的材料，能适合于生产出均匀的并完全压实的混凝土块，这一点也是很重要的。 Weathering风化作用 Deterioration of concrete by weathering is usually brought about by the disruptive action of alternate freezing and thawing of free water within the concrete and expansion and contraction of the concrete,under restraint,resulting from variations in temperature and alternate wetting and drying. disruptive：分裂性的，破坏的； 因风化产生的混凝土劣化，通常是由混凝土中自由水的交替冻融和在约束条件下因温度变化及干湿交替所引起的混凝土的膨胀和收缩所引起的。 Damage to concrete from freezing and thawing arises from the expansion of pore water during freezing; 混凝土因冻融引起的破坏是由结冰后孔隙水的膨胀造成的； In a condition of restrai