钢纤维混凝土拌和
为防止钢纤维混凝土在搅拌时纤维结团,在施工时每拌一次的搅拌量不宜大于搅拌机额定搅拌量的80%。采用滚动式搅拌机拌和,在搅拌混凝土过程中必须保证钢纤维均匀分布。为保证混凝土混合料的搅拌质量,采用先干后湿的拌和工艺。投料顺序及搅拌时间为:粗集料→钢纤维(干拌1min)→细集料→水泥(干拌1min),其中钢纤维在拌和时分三次加入拌和机中,边拌边加入钢纤维,再倒入黄砂、水泥,待全部料投入后重拌2min~3min,最后加足水湿拌1min。总搅拌时间不超过6min,超搅拌会引起湿纤维结团。按此程序拌出的混合料均匀。尚若在拌和中,先加水泥和粗、细集料,后加钢纤维则容易结成团。而且纤维团越滚越紧,难以分开,一旦发现有纤维结团,就必须剔除掉,以防止因此而影响混凝土的质量。
In order to prevent the agglomeration of steel fiber concrete during mixing, the mixing quantity should not be greater than 80% of the rated mixing quantity of the mixer at each mixing time. Mixing with rolling agitator must ensure uniform distribution of steel fibers in mixing concrete. In order to ensure the mixing quality of concrete mixture, a dry and wet mixing process is adopted. The order of feeding and mixing time are as follows: coarse aggregate steel fiber fine aggregate cement dry mixing 1 minute. Steel fiber is added to mixer three times in mixing time, steel fiber is added to mixer while mixing, then yellow sand and cement are poured into the mixer. After all the materials are put into the mixer, they are re-mixed for 2 to 3 minutes, and finally wet mixed with sufficient water for 1 minute. The total stirring time is no more than 6min. Super mixing will cause wet fiber agglomeration. The mixture is evenly distributed according to this procedure. In addition, if cement and coarse aggregate are added to the mixture, then steel fiber will be used to form a cluster. And the fibers are rolling tighter and tighter, so it is difficult to separate them. Once the fibers are found, they must be removed to prevent the quality of concrete from being affected.