Study On The Effect Of Pebble Manufactured Sand In Mountain Area On Properties Of Cement-based Materials

With the development and improvement of transportation infrastructure,the demand for cement-based materials is increasing,and sand,as one of the important factors of cement-based materials,is required higher and higher quality.This paper is mainly based on the Guangping high-speed project,which is located in the mountainous area of Qingchuan County.There are abundant pebbles in the mountain rivers along the route,but the pebbles in the mountainous area are complex and there are few systematic studies.In this paper,the pebble sand in the Qingchuan mountainous area is used as the raw material.From the physical and chemical properties of the pebble sand,the physical properties of the pebble sand on the performance and mechanical properties of cement-based materials,the physical properties of the pebble sand on the dispersion of strength These three parts carry out experimental research and provide valuable reference for the application of pebble sand in the area.Firstly,taking the pebble sand in mountainous areas as the main research object,the physical and chemical characteristics of pebble sand along the Guangping Expressway were studied.The results show that the pebble manufactured Sand has the largest proportion of silica;the pebble manufactured San has the powder content and MB value,Particle gradation,crushing index fluctuation range is large,take the above four physical characteristics as key indicators,and study the correlation between them.The powder content of pebble manufactured San is correlated with MB value,porosity and bulk density.There is no correlation between the fineness modulus of pebble sand and crushing index.Secondly,the effects of pebble mechanism sandstone powder content,MB value,particle grading,and crushing index on the performance of cement-based materials were studied.The results show that:(1)The appropriate amount of pure stone powder content and fine powder content will increase the cement-based material’s performance.Working performance and mechanical properties.Under this test condition,when the content of pure stone powder is 10%,the cement-based material has good workability and high strength.When the content of fine powder is 10%,the cement-based material has good workability,and when the content of fine powder is 5%,the strength of the cement-based material is higher;(2)The coarse particles in the pebble sand increase,and the fluidity of the mortar increases Large;(3)The impact of different pebble mechanism sand gradations on the strength of cement-based materials shows irregular changes;(4)As the crushing index of pebble mechanism sand increases,the overall trend of mortar strength becomes smaller,while the concrete strength No significant changes.Finally,the influence of the pebble mechanism sandstone powder content,MB value,particle grading,and crushing index on the strength dispersion of cement-based materials was studied.The results are obtained through numerical analysis:(1)The pure stone powder content and fine powder content of the pebble mechanism sand will affect the dispersion of the strength of the cement-based material.In order to ensure the homogeneity of the cement-based material structure,the pure stone powder or fine powder in the pebble mechanism sand The content is preferably between 5% and 10%;(2)The gradation of pebble sand particles will affect the dispersion of the strength of cement-based materials,and the dispersion of the strength of cement-based materials prepared by grading sand in zone Ⅱ is small;(3)The crushing index of the pebble mechanism sand has little effect on the dispersion of the strength of cement-based materials.