Experimental Study On The Effect Of Different Compaction Methods On The Cracking Performance Of Semi-rigid Base

The semi-rigid base layer has the characteristics of high strength,high rigidity,good water stability,and good resistance to freezing and thawing,and can produce protective effects on the road surface layer and the base layer.This makes it widely used in China's superhighways,but the widespread cracking of semi-rigid bases seriously affects the road performance and life.In this paper,based on the cracking mechanism of semi-rigid base layer,the influence of compaction quality of semi-rigid base layer on its cracking phenomenon is analyzed,the test of the relationship between compaction quality and the anti-cracking performance of semi-rigid base material is conducted in the laboratory and oriented by the improvement of the quality of base layer compaction,the quality of compaction that can effectively improve the anti-cracking performance of the semi-rigid base layer will be explored by comparing the compaction abilities of different compaction methods.The main tasks of this paper are:The cracking types of semi-rigid bases are classified,and the cracking mechanism is analyzed in depth.According to the defects of the existing semi-rigid base layer crack suppression technology,a method of improving the anti-cracking performance of the base by improving compaction quality is proposed.The impact of compaction quality on the mechanical properties and shrinkage properties of the semi-rigid base was analyzed,and the conclusion was reached that the improvement of compaction quality can effectively enhance the crack resistance of the layer.Using the cement stabilized macadam as the test object,the crack resistance of the different specimens was analyzed;the technical characteristics of the circumferential vibration,vertical vibration and the dual-frequency synthetic vibration compaction were analyzed.Using a small proto type as the platform,the compaction test of the three compaction methods was carried out,and compare the compaction capacity of each compaction method.The test results show that the degree of compaction of the semi-rigid base material is positively correlated with its crack resistance.When the degree of compaction of the semi-rigid base increases by 1%,the unconfined compressive strength,splitting strength,and bending strength increase respectively.8.13%,9.94% and 2.01%.The shrinkage coefficient and the coefficient of shrinkage are reduced by an average of 2.83% and 5.48%.Compared with other compaction methods,the two-shot synthesis vibratory compaction method has the highest compaction ability when the power consumption is small,and it can effectively improve the crack resistance of the semi-rigid base layer.The compaction method.