Steel fibers effect

An interesting application involves the use of very fine (15 p,m) stainless steel filament as a conductive filler in a thermoplastic resin for electromagnetic shield ing. According to Nippon Steel and Nippon Seisen Co., who developed this product called Esbarrier, 4-10 wt% of stainless steel fiber provides an effective shielding of 40-50 dB at 100 MHz. 

Different steel fibers were used the effect of steel fibers in a PC system manifests as an increase in compressive, flexural, and impact strengths. 

As seen in Fig. 4.22,1 ° the addition of steel fibers into latex-modified systems has a positive effect on the strength with increasing polymer-cement ratio and steel fiber content. In general, the flexural and compressive strengths can be predicted by the following equations f391... 

There are a range of conductive polymers on the market that are based on metal fillers such as aluminum flake, brass fibers, stainless steel fibers, graphite-coated fibers, and metal-coated graphite fibers. However, the most cost effective conductive filler is carbon black. Mention should also be made of... 

In some studies, external loads have been exerted upxin the concrete kept in a NaCl solution under the influence of effective freeze-thaw cycles. The concrete spiedmens expased to NaCl have been shown to lose twice as much weight as those expxised to water. Sp>ecimens with steel fibers lose weight maximum at the w/c ratio of 0.44 that becomes obvious after 20-25 cycles. As the rate of the tension of the burdens exerted increased, resistance of the concrete spjecimens to cycles decreased. Addition of steel fibers in concrete specimens has been shown to cause a delay in a decrease in the performance of the concrete in the advanced cycles in comparison with the concrete without fiber (Sun et al., 2002 Mu et al., 2002 Miao... 

In this study, micro-structured polypropylene and glass fibers were both used sep>arately and in combination with macro-structured steel fibers in the concrete. Experiments were conducted in order to determine weight-loss and durability factor based on ultrasoimd pulse velocity of 12 different concrete series produced according to ASTM C-666. The separate and combined effects of the fibers used in the concrete in terms of the rapad freeze-thaw period were investigated. 

As seen in Fig. 2, the decrease in the pulse velocity of the specimens was obvious in contrast to their weight-loss. Polypropylene fibers demonstrated the best performance as a standalone and mixed with steel fibers (Morgan, 1991). A similar effect was determined for the mixture fibers. Fibers did affect the concrete specimens in agreement with their own properties. Because of the capability of polypropylene fibers to prevent cracking and to be remarkably safe from corrosion, the pulse velocity value was determined to be low. 

Miao, C. Mu, R. Tian, Q. Sun, W. (2002). Effect of Sulphate Solution on the Frost Resistance of Concrete with and without Steel Fiber Reinforcement, Cement and Concrete Research, Vol. 32, No. 1, pp. 31-34, ISSN 0008-8846. 

Igarashi, S., Bentur, A., Mindess, S. (1996) The effect of processing on the bond and interfaces in Steel Fiber Reinforced Cement Composites , Cement and Concrete Composites, 18(5) 313-22. 

Yan, H., Sun, W., Chen, H. (1999) The effect of silica fume and steel fiber on the dynamic mechanical performance of high-strength concrete, Cement and Concrete Research, 29 423-6. 

In the course of their studies, Chung and her colleagues evaluated the effectiveness of aluminum flakes, coated and uncoated carbon fibers, nickel fibers, stainless steel fibers, combinations of flakes and fibers, and low melting-point metal alloys. 

Better conductivity than with carbon black can be achieved with metal particles. Common are copper or aluminum in the form of powder or flakes, as well as brass, carbon, and stainless steel fibers. To increase the effective surface, electrically neutral filler particles are coated with metal, e.g., nickel-plated glass fibers or small spheres, silver or nickel-coated mica or silicates [23, 27, 29]. 

Fig. 19.75 Measurements of shielding effectiveness under various conditions on four different samples of compounds of conductive polymers (all samples contain dispersed ICP as the conductive phase from top to bottom. Nos. 4, 10. 7, and 9 from Table 19.7). They are compared with a 109/ stainless steel fiber compound. (From Ref. 95.)...

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