Research On Texturing Technology Of Tunnel Concrete Pavement And Anti-skid Performance Evaluation

As highway construction gradually extends to mountainous and hilly areas,the proportion of tunnels in highways is increasing,and most of them are cement concrete pavements.The anti-skid performance of tunnel cement pavement decays too fast in the early stage.Therefore,part of long tunnels had adopted HOG arc-texturing to improve the anti-skid performance of concrete pavement.Macro and micro textures are the main influencing factors of pavement anti-skid performance,but the existing evaluation methods cannot reflect the degree of influence of the above two factors.Therefore,this research carried out the study of the anti-skid performance mechanism of HOG cement concrete pavement and the optimization of textured parameter design,then proposed an objective cement pavement texture evaluation method Besides,a comprehensive evaluation system of anti-skid performance to guide the design of similar projects,and improve construction quality.Firstly,blending method was adopted to optimize the mix ratio,specifically the gradation of the coarse and fine aggregate of the mixture were optimized,and the influence of the gradation change on the strength of the concrete was analyzed.Meanwhile,the machine-made sandstone properties and the ratio of natural sand to machine-made sand were adjusted in order to analyze the influence on the abrasion.The results showed that the abrasion of the concrete was the smallest when the blending ratio of basalt machine-made sand used in the research was50%,and the texturing mold can be used to make textured samples currently.Secondly,a three-dimensional laser anti-slip scanner was used to collect the elevation data of the pavement,and the data was spliced to analyze the influence of different filtering methods on the accuracy of the model.The least squares surface method was used to corrected the inclination of model,and the self-compiled Matlab program was used to calculate and analyze anti-sliding indicators,including MTD,distribution area of macroscopic structural peak and density of microscopic texture.Then,the pressure film measurement technology was used to obtain the contact stress distribution between the tires and the pavement,showing that contact stress distribution was typically non-uniform and insufficient;then the Weibull model was proposed to characterize the four types of pavement contact stress distributions,and the results showed that all of the correlation coefficient were above 0.95;the effective contact area ratio calculation index was adopted,and the stress distribution concentration coefficient evaluation index was established based on the actual tire-pavement contact characteristics,and the calculation method of tire steering resistance torque was optimized,which showed that the ratio of effective contact area can well represent the full degree of contact between the tires and pavement,and the ratio of effective contact area increases with the increase of the pavement roughness;the stress distribution concentration was related to the roughness of pavement,and compared with the rectangular grooved pavement,the textured pavement has a higher degree of congestion with the pavement,which further verifies the effectiveness of texturing to improve the anti-skid performance.Finally,the self-developed texture specimen engraving molds were used.Through the orthogonal test and the rubbing wear test,the influence of different texture parameter combinations on the anti-skid performance and driving stability were studied,which showed that texture depth was the most important factor affecting the MTD and stress distribution concentration,while texture width was the most important factor affecting steering resistance torque.After analyzing and comprehensively comparing the effects of various parameters,the best parameter combination of this research was obtained,and the driving stability and the durability of the anti-skid performance can be balanced effectively by setting a certain textured spacing and textured group spacing.Through engineering verification,the attenuation of the anti-skid performance of the textured pavement was tracked,and the results showed that the actual attenuation law was consistent with that of laboratory test,meanwhile,the evaluation index used in this study can be adopted well to characterize the anti-skid performance of the cement pavement.