Experimental Research On Anti-erosion And Freeze-thaw Properties For Steel Fiber Reinforced Fly Ash Concrete

Theories of steel fiber reinforced fly ash concrete were analyzed. Firstly, experimental research was conducted on the strength development law of steel fiber reinforced fly ash concrete (SFRFAC). Under the same mixing amount of water reducing agent (0.75%), cube compressive strength and flexural strength of SFRFAC was increased and then decreased, with the increase of mixing amount of fly ash and steel fiber volume. Mixing amount of fly ash have an obviously effect for compressive strength and flexural strength of SFRFAC. Steel fiber volume have an obviously effect for flexural strength of SFRFAC, but have a little effect for compressive strength of SFRFAC. The compressive strength and flexural strength are higher than others as steel fiber volume was 1.2%, and mixing amount of fly ash was 30%. Splitting tensile strength increases with addition of steel fiber volume in a certain range. Splitting tensile strength of SFRFAC was increased and then decreased, with addition of mixing amount of fly ash. Splitting tensile strength is higher than others as steel fiber volume was 1.8%, and mixing amount of fly ash was 30%.Secondly, experimental research was conducted on softening coefficient and erosion compressive resistance, erosion flexural of SFRFAC. Softening coefficient of plain concrete (PC), steel fiber reinforced concrete (SFRC), fly ash concrete (FAC), SFRFAC were contrasted. Experimental research was conducted on softening coefficient. It is shown that softening coefficient of SFRFAC is higher than others, and has a higher water resistance. Compressive and flexural strength of PC, SFRC, FAC, SFRFAC erosion 30 cycles in different concentration were analyzed. After erosion 30 cycles into 100mg/L,1000mg/L,10000mg/L sodium sulfate solution, cube compressive strength of PC was decreased 12.6% and then increased 9.8% with addition of concentration from100 mg/L to 10000mg/L.Flexural strength of PC was increased 6.7% and 1.5%. Cube compressive strength of SFRC was decreased 5.7% and then increased 09% with addition of concentration from100 mg/L to 10000mg/L.Flexural strength of SFRC was increased 11.2% and 1.9 %.However, cube compressive strength of FAC was decreased 1.7% and then increased 0.5% with addition of concentration from100 mg/L to 10000mg/L. Flexural strength of FAC was decreased 4.5% and then increased 6.4%. Cube compressive strength of SFRFAC was decreased 5.6% and then increased 2.2% with addition of concentration from100 mg/L to 10000mg/L. Flexural strength of SFRFAC was decreased 10.7% and then increased 6.6 %. Cube compressive strength and flexural strength of SFRFAC are higher than other concrete.Finally, experimental research was conducted on erosion freeze-thaw characteristics of SFRFAC beam. Erosion freeze-thaw characteristics were contrasted and analyzed. The experimental result indicated: the flexural strength of SFRFAC beam without erosion freeze-thaw is obviously higher. After erosion 30 cycles into 100mg/L,1000mg/L,10000mg/L sodium sulfate solution, the flexural strength of SFRFAC beam were decreased 7.1%,6.4%,12.0%. The flexural strength of SFRFAC beam was increased appreciably, and then decreased with addition of concentration from100 mg/L to 10000mg/L.Steel fiber and fly ash greatly improve the durability of SFRFAC such as anti erosion freeze-thaw. SFRFAC beams were more severe damaged by erosion freeze-thaw interaction than erosion and erosion freeze-thaw, especially for 10000mg/L sodium sulfate solution.