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用传统方法配制高强混凝土有很大的局限性:水泥用量大,工作性差,早期强度低,收缩与徐变大等,因而国内混凝土强度长期徘徊于低塑性C40-C50间。而高效减水剂的开发与应用为配制高强混凝土提供了使用方便、经济而又易于推广的有效方法。FDN高效减水剂系列产品,主要成份是β-萘磺酸钠甲醛高缩合物,其特点是缩合度高,对水泥分散力强,减水率高(达14～25％),引入空气量少,可使水灰比降至0.30以下,使混凝土结构非常密实,可提高混凝土的强度20～40％(早期强度可提高40～80％),因而特别适宜于配制C50～100的高强和超高强混凝土。由于使用方便,不需改变混凝土的成型工艺,不需增加设备,费用低廉,技术经济效益显著。因而FDN系列产品已在铁路、公路以及港口建筑等工程上广泛使用,掺FDN系列产品混凝土强度水平普遍已达到:现浇混疑土C50～60;预制混凝土达C60～70。
The traditional method of formulating high-strength concrete has a lot of limitations: large amount of cement, poor workability, low early strength, large shrinkage and creep, etc. Therefore, the strength of domestic concrete has long been limited by low plasticity between C40 and C50. The development and application of high-efficiency water-reducing agent provides a convenient, economical and easy-to-promote method for formulating high-strength concrete. FDN high-efficiency water-reducing agent series products are mainly composed of β-naphthalene sulfonic acid sodium formaldehyde high condensate, which is characterized by high degree of condensation, strong dispersion of cement, high water reduction (up to 14-25%), and introduction of air volume. Less, the water-cement ratio can be reduced to less than 0.30, so that the concrete structure is very dense, can increase the strength of concrete 20 to 40% (early strength can be increased by 40 to 80%), and thus especially suitable for the preparation of C50 ~ 100 high strength and super High-strength concrete. Due to its ease of use, there is no need to change the molding process of concrete, no additional equipment, low cost, and significant technical and economic benefits. Therefore, FDN series products have been widely used in railway, highway and port construction and other projects. The concrete strength of FDN series products has generally reached: C50-60 for cast-in-place concrete, and C60-70 for precast concrete.