The effect of different dosage for SanQi micro steel fiber

             The effect of different dosage of copper coated steel fiber on the concrete
 
 
RPC concrete base mixed proportion as following: cement: sand: quartz powder: silica fume as 1:1.12:0.132:0.115. Superplasticizer according to the proportion of incorporation of 2%, copper coated steel fiber according to 0%, 2%, 4% and 6%,the size of specimen mixed copper steel fiber is 40mm × 40mm × 160mm
Chart1 show the compressive strength and flexural strength: c and f show respectively  compressive strength and flexural strength, Κ show the percentage of steel fiber. With the increasing dosage of steel fiber, the compressive strength and flexural strength of the RPC added copper coated steel fiber also increases, when the fiber dosage from 2% to 6 %, the compressive strength increased from 161.13MPa to 201.13MPa; when the dosage is less than 2%, the flexural strength increased less, further increasing the dosage, the flexural strength is rapidly increasing, when the dosage is 6%, the flexural strength 73.167MPa,the maximal compressive strength and flexural strength with respect to non-fiber RPC increased by 3,813% and 17,611%.
 

Chart 2 show the Influence of steel fiber dosage on RPC liquidity. L ordinate indicates the degree of diffusion, Κ abscissa represents the percentage of steel fiber. Visibly, the liquidity of concrete with steel fiber content increasing significantly reduced. Copper coated steel fiber fiber, when its dosage is more than 2%,has greater impact on liquidity

               
 
Chart 3 show the affecting of the impact properties of steel fiber RPC
n is the number of times of the impact, that is the ratio value of RPC with steel fiber cracking frequency and plain concrete cracking frequency. Κ abscissa represents the dosage percentage of steel fibers, with steel fiber dosage% increases, steel fiber RPC impact resistance is also improved. Under dynamic loads, steel fiber concrete during crack propagation, firstly steel fiber will overcome substrate adhesion and is pulled out, or steel fibers reaches the yield and pulled off. This requires a lot of energy. Therefore, steel fiber reinforced concrete can improve the impact resistance .When the steel fiber dosage % is more than 3%, the cracking frequency is three times the one of plain concrete; steel fiber doped the amount of 6%, the cracking frequency is 8times the one of plain concrete; when copper coated steel fiber dosage % is 9%, the crack frequency is 10 times the number of plain concrete.