基于结构韧性提升的超薄磨耗层层间处治设计

Interlayer Treatment Design of Ultra-thin Wear Layers Based on the Improvement of Structural Toughness

为提升超薄磨耗层的结构韧性和整体协同受力,提出一种“V”形开槽抗裂缝反射处治技术和特种不粘轮乳化沥青黏层组合的层间处治设计方案。通过室内复合试件的剪切试验和拉拔试验,对比分析了特种不粘轮乳化沥青的黏结效果,并使用法国Alize路面结构设计程序计算出了不同层间黏结状态下的路面结构使用寿命。通过有限元软件ABAQUS对路面结构进行了力学分析,验证“V”形开槽技术的抗裂缝反射效果。最终通过依托工程的现场实施和对比分析,验证采用该层间处治设计方案的实际使用效果。结果表明:特种不粘轮乳化沥青的层间黏结效果明显优于普通乳化沥青和改性乳化沥青,是一种性能优良的层间黏结材料,在最佳乳化沥青用量下,可分别延长使用寿命59.8%和34.8%;“V”形槽结构的槽底尖端形状可形成孔洞效应,能有效消减裂缝尖端应力集中,“V”形槽结构的应力强度因子K始终小于普通路面结构,说明“V”形开槽技术能够有效抑制动载作用下的裂缝扩展;从现场观测来看,采用“V”形开槽技术处治后的横向裂缝尚未发展到道路表面,而采用普通灌封工艺处理的横向裂缝已发展到道路表面,且整个试验段无其他病害产生,证明该层间处治设计方案使用效果良好,可有效提升超薄磨耗层的结构韧性。

In order to improve the structural toughness and overall cooperative stress of ultra-thin wearing course,an interlayer treatment design scheme based on the combination of“V”slotted anti crack reflection treatment technology and special non stick wheel emulsified asphalt adhesive layer was proposed.Through the shear test and pull-out test of indoor composite specimens,the bonding effect of special non stick wheel emulsified asphalt was compared and analyzed,and the service life of pavement structure under different interlayer bonding states was calculated by using the French Alize pavement structure design program.The mechanical analysis of pavement structure was carried out through ABAQUS to verify the anti crack reflection effect of“V”slotting technology.Finally,through the on-site implementation and comparative analysis of the supporting project,the actual application effect of the interlayer treatment design scheme was verified.The results show that the interlayer bonding effect of special non stick wheel emulsified asphalt is obviously better than that of ordinary emulsified asphalt and modified emulsified asphalt.It is a kind of interlayer bonding material with excellent performance.Under the optimal dosage of emulsified asphalt,the service life can be prolonged by 59.8%and 34.8%respectively.The shape of the groove bottom tip of the“V”groove structure can form a hole effect,which can effectively reduce the stress concentration at the crack tip.The stress intensity factor K of the“V”groove structure is always lower than the ordinary pavement structure,indicating that the“V”groove technology can effectively inhibit the crack expansion under dynamic load.From the field observation,the transverse cracks treated by“V”slotting technology have not yet developed to the road surface,while the transverse cracks treated by ordinary pouring and sealing technology have developed to the road surface,and there are no other diseases in the whole test section,which proves that the application effect of the interlayer treatment design scheme is good,it can effectively improve the structural toughness of ultra-thin wearing course.