微粘结级配碎石基层的性能分析

Performance Analysis of Micro-Bonded Graded Crushed Stone Base

级配碎石柔性基层存在回弹模量小及永久变形大的缺陷,容易导致面层的网裂和过大的车辙;水泥稳定碎石半刚性基层存在干缩温缩大的缺陷,容易导致路面产生反射裂缝。从解决二者的缺陷入手,提出采用微粘结级配碎石作为路面的基层,通过室内试验确定不同水泥剂量的微粘结级配碎石材料的CBR值和无侧限抗压强度,以此分析合理的水泥剂量。结果表明:随着水泥掺量的增加,级配碎石的CBR增大,但是过多的水泥掺量会使路面基层呈现半刚性基层,干缩温缩大,反射裂缝明显。微粘结级配碎石材料可以用作路面基层,能提高纯级配碎石的模量,提高级配碎石的施工和易性、减少沥青路面反射裂缝。

The flexible base of graded crushed stone has the defects of small resilience modulus and large permanent deformation,which can easily lead to network cracks and excessive rutting of the surface layer.The semi-rigid base of cement stabilized crushed stone has the defect of large dry shrinkage and temperature shrinkage,which is easy to cause reflection cracks on the road surface.In order to solve the defects of the two types of base,this paper proposes to use the micro-bond gradation gravel as the base of the pavement.The CBR value and unconfined compressive strength of micro-bonded graded gravel with different cement dosage were determined by laboratory test,and the reasonable cement dosage was analyzed.The results show that with the increase of cement content,the CBR of graded crushed stone increases.However,the excessive amount of cement will make the pavement base show the characteristics of semi-rigid base,with dry shrinkage and temperature shrinkage,and obvious reflection cracks.Microbonded graded gravel can be used as pavement basewhich can improve the modulus of pure graded gravel,improve the workability of graded gravel construction and reduce the reflection cracks of asphalt pavement.