With the development of economy and the progress of science and technology, great achievements have been made in engineering construction in our country. Engineering materials are also constantly bringing forth new ideas, especially wavy steel fibers. Wave steel fibers are made by cutting thin steel wires, shearing cold rolled strips, milling ingots or rapid condensation of molten steel to grow diameter ratio (the ratio of fiber length to diameter, when the cross section of fibers is non-circular, conversion is equivalent). The diameter of the circular area of the cross section is 30-100 fibers.
由于波浪形钢纤维与混凝土基体的界面粘结主要是物理性的,即以摩擦剪力的传递为主,因此对钢纤维本身来说,应该从纤维表面和纤维形状两个方面来改善其粘结性能。
As the interface bond between corrugated steel fibers and concrete matrix is mainly physical, that is, the transfer of friction and shear force is the main factor, the bond performance of steel fibers should be improved from two aspects: the surface of fibers and the shape of fibers.
使波浪形钢纤维表面粗糙化、截面呈不规则形。采用熔抽法生产就能达到这个目的。因为钢纤维在遇空气急剧冷却时,表面收缩不均匀而变得粗糙,同时截面也收缩成月牙形,增加与基体的接触面积。铣削型钢纤维一个表面光滑,另一个表面粗糙,也增加了与混凝土的接触面积
The surface of wavy steel fibers is roughened and the cross section is irregular. This can be achieved by melt extraction. When steel fibers are cooled sharply by air, the surface shrinkage becomes uneven and rough. At the same time, the cross section shrinks into crescent shape, which increases the contact area with the matrix. Milled profiled steel fibers have a smooth surface and a rough surface, which also increases the contact area with concrete.
沿波浪形钢纤维轴线方向按一定间距对纤维进行塑性加工。由于表面压成棱形,或压成波形,增加了机械粘结力。
Plastic processing of wavy steel fibers is carried out at a certain distance along the axis direction of the wavy steel fibers. As the surface is pressed into prism or waveform, the mechanical bonding force is increased.
无论哪一种加工方法制造的波浪形钢纤维,在加工过程中都遇到高热和急剧冷却,相当于淬火状态。因此钢纤维的表面硬度都较高。用于混凝土补强进行搅拌时很少发生弯曲现象。如果钢纤维过硬过脆,搅拌时也易折断,影响增强效果。在熔抽法生产波浪形钢纤维时,从熔抽轮下离心喷出的钢纤维仍处于高温状态,必须用滚筒或振动输送方法分散并进行冷却。否则波浪形钢纤维聚集,热量难以散发,反而起退火作用。
The wavy steel fibers manufactured by either method are subjected to high heat and rapid cooling during processing, which is equivalent to quenching. Therefore, the surface hardness of steel fibers is jiashan.37ix.com.cnyinyue.37ix.com.cnpailou.37ix.com.cngongcheng.37ix.com.cnyuanlin.37ix.com.cn
shumiao.37ix.com.cnhigher. The bending phenomenon rarely occurs when concrete is stirred for reinforcing. If the steel fiber is too hard and too brittle, it will break easily when stirring, which will affect the reinforcement effect. In the production of corrugated steel fibers by melt pumping, the steel fibers centrifugally ejected from the melt pulley are still in a high temperature state, which must be dispersed and cooled by means of drum or vibration conveying. Otherwise, the wavy steel fibers gather and the heat is difficult to dissipate, instead, they act as annealing.
