Study on frost resistance and pore structure of polypropylene plastic fiber concrete
In order to solve the problem of insufficient frost resistance of concrete buildings and structures in western Jilin Province,the variation law of compressive strength of concrete with the polypropylene plastic fiber content of 0 kg/m3、3 kg/m3、6 kg/m3 and 9 kg/m3 after 0、50、1 00、1 50 and 200 times freeze-thaw cycles is studied,and the area and distribution of T2 spectrum and pore structure were studied by using low magnetic field nuclear magnetic resonance technology.With the help of the scanning electron microscope,the changes of micro-pore structure of concrete with the different polypropylene plastic fiber content before and after freezing and thawing were analyzed,and finally the relationship between compressive strength of concrete and internal micro-pore structure and pore distribution under freezing and thawing environment was explored.The results showed that with the increase of freeze-thaw cycles,the compressive strength of concrete with the different contents of the polypropylene plastic fiber decreased to varying degrees.The overall T2 spectrogram showed the trend of moving to the right,with the area and proportion of T2 spectrogram of peak a decreasing gradually,while the area and proportion of T2 spectrogram of peak b and peak c increasing gradually,and the proportion of peak c increasing faster than that of peak b.The compressive strength of concrete reinforced by the polypropylene plastic fiber was negatively correlated with the proportion of harmful pores and multi-harmful pores in it during freezing and thawing.Generally speaking,the 6 kg/m3 polypropylene plastic fiber had the best effect on improving the frost resistance of concrete,and the proportion of harmful pores and multi-harmful pores in it was the least.
万方数据
维普
