The Research On Preventive Reinforcement In View Of Semi-rigid Base Damage Evaluation

Because of the high strength, the overall carrying capacity and reasonable cost,semi-rigid asphalt pavement structure is used to our country’s highway construction largely.But more and more practice shows that, semi-rigid base is too easily lead to the roadsurface reflection crack because of its desiccation crack and temperature shrinkage crack.And then under the influence of water damage, those cracks cause the pavement structuraldamage eventually.Road base has been the lack of accurate state evaluation method because of itsinvisibility. With increasing of the degree of conservation, highway preventivemaintenance has been more attention, that technology, construction and gradually becomemature. But it has been stuck in the surface layer, the lack of links and grasp on thestructural integrity.On the basis of the preventive maintenance techniques, in this paper, we proposed thenew concept of “preventive reinforcement” with handling objects in depth extension. Itwas a joint conservation behavior measure link surface with road base, under the positionof construction with overall strength and only minor damage, used to achieve thedestruction of the prevention of deep-level effect, extend the service life and maximize thebenefits. And then we established the Semi-rigid base preventive reinforcement system,determined the road standards, decision-making system, testing evaluation method of it byanalysis of causal association with early damage of the asphalt pavement and road base. Atlast, we do a project preliminary evaluation for road base preventive reinforcement.Road base state evaluation is the most basic question of the road base preventivereinforcement system. Then we draw on existing research of domestic and international,adjust the surface curvature index SCI, road base damage indicators BDI by the analysis ofsemi-rigid base deflection basin curve geometry features. Finally we determine thedeflection basin parameters D0-D20and D20-D60, which reflects the strength of surfacelayer, base layer respectively.Finally, with the implementation of Beijing-Zhuhai expressway road basereinforcement project, we determined the limit value standard of SCI and BDI by thecomparative analysis with the disease sections, primary cracks sections, and base loosesection,,and then further proposed the macroscopic and microscopic standard ofpreventive reinforcement system.The results of shows that, the road standards, evaluation can objectively reflect theuse of state of the pavement surface and road base, and the road after the primarypreventive reinforcement able to achieve the desired effect. The semi-rigid base preventivereinforcement can be an effective solution to the current highway pavement maintenancedecisions related issues, and proposal the new direction of preventive maintenance development.