Permeability Prediction Of Textile Reinforced Concrete Based On Pore Fractal Dimension

Textile reinforced concrete?TRC?has been used in the repairing of oldstructures due to its excellent mechanical properties and durability.Availability of moisture and gas entering for concrete matrix is the most responsible the durability of TRC.This paper is funded by the Natural Science Foundation of China?41627801,41430642,51108207?,the Chinese Postdoctoral Science Foundation of China?2015M581403?,as well as the Open Fund of the State Key Laboratory of Frozen Soil Engineering?SKLFSE201514?.The fractal dimension was introduced as a parameter to characterize the roughness to describe the permeability of TRC.Based on the dimensional analysis method combined with the TRC permeability test,a prediction model combining experimental results and theoretical analysis was established.This model is a TRC permeability model with fractal dimensions.The main work of this article is as follows:?1?The textile fiber size,fiber bundle TEX content,and water-cement ratio were selected as experimental variables.The TRC permeability test was conducted,and the relative permeability coefficient of the TRC permeability was calculated via the water penetration method.After completing the TRC permeability test,analyze the distribution pattern and the height difference of the watermark.?2?The electron microscope test was performed to observe the difference between the concrete matrix near the fiber bundle and the concrete matrix farther away from the fiber bundle;at the same time,the value of the cracks was measured and the average value was calculated.The NMR test was performed to analyze the pore distribution law in the T₂ spectrum and calculate the fractal dimension of TRC,which was used as a characteristic parameter of the roughness of the concrete matrix near the fiber bundle.?3?Analyze the influencing factors that affect the permeability of TRC and use these factors as basic physical quantities.Obtain the logical relationship between the factors based on the dimensional analysis method.Analyze the actual situation in the TRC permeability test,and compare the logical relationship with the classic formula of the parallel cube crack law.Then a roughness function related to the fractal dimension of the roughness characterization parameters is obtained.The TRC permeability model based on the fractal dimension is established by taking the roughness function into account.The model is a prediction model combining experimental results and theoretical analysis,and then verify the reliability of this model.