外文翻譯---粉煤灰高性能混凝土的工程應(yīng)用-wenkub
2023-05-19 08:57:14 本頁(yè)面
【正文】 modern, whose name is already with cement in fly ash, collect material , water , admixture and Kind is important, bee a ponent part in concrete. Fly ash highperformance concrete re】 gard durability as main goal go on design mix Congeal the soil . It regards excellent durability (instead of the high strength) as the main characteristic , that is to say, concrete capital of any grade of intensity Can make into the high durability concrete . In order to reach high durability, the performance that the fly ash concrete】 should possess is: Mixing the state newly well Work,namely, without emanating, secreting by water, so that shaping the even , closely knit by mobility, harden not shrinking subsiding early water and Water shrink light, warm to rise low, harden course is it dwindle to do, in order to reach having the initial crack, the permeability after hardenning is low. ． function and effect of the fly ash are fly ash material technology and application foundation of the project. he conicrete Coal ash, in conformity with understanding that the function of the fly ash is made overallly, by volcanic ash react and economic ponent part general to fly ash originally Read , expand technological consciousness of fly ash effect to , make fly ash function can serve performance of concrete improve with quality raising better. The role in concrete of fly ash has the following several points: minium that the main mineral of the fly ash makes up , smooth the body surface of these spherical glass, the grain size is thin, the quality is prepressing, inside smaller than the surface area, the strength of absorbing to water is small, this line of physical characteristics, reduce concrete rub obstruction inside , favorable to improvement , concrete of mobility not merely。 link in the concrete structure to collect the interface between the material and cement stone, width of transition area as water for dust than, collect there aren’t material , transition area have than grout body more, heavy hole. Mixing can reduce the regional width of the transition to add the fly ash , interfere Ca (OH ) orientation of 2 crystal in the transition area, improve the intensity of interface and density in the concrete. concrete performance can be divided into three stages: 1 . Mix concrete stage newly: Influence the coagulation time of the concrete , is improving and easy , change rheology nature , can improve pump ,etc.。 ⑵ .Mix particle apt to gather group cement in the concrete newly, to is it can disperse cement particle effectively to mix fly ash, release more thick liquid body is it lubricate aggregate to e , help concrete work the improvement of performance 。優(yōu)質(zhì)粉煤灰合理地應(yīng)用于混凝土中，不但能部分代替水泥，節(jié)省工程造價(jià)，而且，其特有的性能可以很有效地用于各種使用要求的混凝土中，改善和提高混凝土的性能，是高性能混凝土中的理想摻和料。為達(dá)到高耐久性，粉煤灰混凝土應(yīng)具備的性能是：在新拌狀態(tài)有良的工作性，即高流動(dòng)性而不離析、不泌水，以使成型均勻、密實(shí)，水化硬化早期的沉降收縮和水化收縮小，溫升低，硬化過(guò)程干縮小，以達(dá)到無(wú)初始裂縫，硬化后的滲透性低。摻加粉煤灰能減小過(guò)渡區(qū)域?qū)挾?，干擾過(guò)渡區(qū)域中 Ca（ OH） 2晶體的取向性，提高混凝土中的界面強(qiáng)度和密實(shí)性。在水泥的最終產(chǎn)物中，高堿性水化硅酸鈣和 Ca（ OH） 2膠體的結(jié)晶強(qiáng)度很低，特別是 Ca（ OH） 2僅是托勃莫來(lái)石強(qiáng)度的 12%，而 Ca（ OH） 2 的體積占整個(gè)水泥石體積的 25%。粉煤灰混凝土的彈性模量與抗壓強(qiáng)度相類(lèi)似，早期偏低，后期逐步提高，到 28d時(shí)可比基準(zhǔn)混凝土提高 510%。 和易性 粉煤灰對(duì)混凝土和易性的改善作用有以下幾點(diǎn)： ⑴ .優(yōu)質(zhì)粉煤灰中含有 70%以上的球狀玻璃體，這些球狀玻璃體表面光滑無(wú)棱角，性能穩(wěn)定，在混凝土的泵送、振搗過(guò)程中起著一種類(lèi)似于軸承的潤(rùn)滑作用； ⑵ .新拌混凝土中水泥顆粒易聚集成團(tuán)，粉煤灰的摻入可有效分散水泥顆粒，釋放更多的漿體來(lái)潤(rùn)滑骨料，有利于混凝土工作性能的提高； ⑶ . 摻入粉煤灰可以補(bǔ)償細(xì)骨料中細(xì)屑的不足，中斷砂漿基體中泌水渠道 的連續(xù)性，同時(shí)品質(zhì)良好的粉煤灰在同樣的稠度下能減少混凝土的拌和用水量，使混凝土中的水灰比降低到更小水平，減少泌水和離析現(xiàn)象 收縮 混凝土的收縮與混凝土的拌和用水量和漿體體積有關(guān)，用水量越少，收縮也越小。為防止粉
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