Experimental Study On Crack Resistance Of Reinforced Cement Stabilized Macadam Base By Basalt Fiber Belt

Based on the common problems of temperature shrinkage and drying shrinkage cracks in semi-rigid base materials,this paper proposes to lay basalt fibre bands in cement stabilized macadam materials to form reinforced material to prevent cracks diseases.Through a large number of laboratory tests,the interfacial characteristics between basalt fiber band and cement stabilized macadam,the basic physical and mechanical properties and crack resistance of reinforced cement stabilized macadam are studied.The main research results include:(1)Based on the basic physical and mechanical tests of basalt fiber belt,the unit area mass,tensile strength and elongation of the material are determined.The test results show that the basalt fiber belt has high tensile strength and low elongation.(2)A set of pull-and-press integrative tester and matching pull-out test models of various sizes were designed,and a complete set of specimen forming and testing methods are mastered.Through this method,using the self-designed instrument and test model,the test data can be well obtained and the research conclusion can be drawn.(3)The interfacial characteristics between basalt fiber band and cement stabilized macadam were studied by drawing test of single basalt fiber band of trabecular specimens and drawing test of multiple basalt fiber bands of beam specimens.Through the trabecular drawing test,it is found that the curing age,the width of basalt fiber band and the section size of the specimen all have influence on the drawing stress.The longer the curing age is,the larger the section size of the specimen is,and the smaller the width of basalt fiber band is,the larger the drawing stress is.Through the drawing test of the girder,it is found that the vertical compression load on the specimen and the width of the basalt fibers have an effect on the pull-out force and the pull-out displacement.The larger the vertical compressive load is,the larger the maximum drawing force and displacement are.However,the wider the width of the basalt fiber belt is,the smaller the maximum drawing displacement is.(4)Through a lot of experiments,the effects of the width and curing age of basalt fiber band on the unconfined compressive strength,splitting strength,flexural-tensile strength,compressive resilient modulus and frost resistance of Cement-Stabilized Macadam Reinforced with basalt fiber band are studied,and the corresponding experimental rules are obtained.With the increase of curing age,its unconfined compressive strength,splitting strength,flexuraltensile strength,compressive resilience modulus and frost resistance are constantly improved;The unconfined compressive strength decreases slightly when the basalt fiber band is laid,and the decreasing range increases with the increase of the fiber bandwidth.The splitting strength of reinforced cement stabilized macadam increases to a certain extent in the middle and later period of curing stage.The laying of basalt fibre belt can obviously improve the flexural tensile strength.To some extent,laying basalt fiber belt can reduce the modulus of compressive resilience of cement stabilized macadam materials.The frost resistance of the specimens can be improved by laying suitable width of basalt fiber belt.(5)Based on the knowledge of thermodynamics and fracture mechanics,the crack resistance mechanism of Cement Stabilized Macadam Reinforced with basalt fiber band is analyzed.Drying shrinkage property and temperature shrinkage property of Cement Stabilized Macadam Reinforced with basalt fiber band are studied through shrinkage property test.The results show that the drying shrinkage strain,drying shrinkage coefficient,temperature shrinkage strain and temperature shrinkage coefficient of cement stabilized macadam can be significantly reduced by laying basalt fiber belt,and reasonable selection of the width of basalt fiber band can not only enhance the material's crack resistance,but also enhance other mechanical properties.