Research And Application Of Asphalt Overlay On Old Cement Concrete Pavement

Asphalt pavements overlays is a very typical reinforcing method in the old cement pavement. For cement concrete pavement, this form of pavement structure can admit the advantages of the two materials:old cement pavement can provide a stable, solid base;asphalt surface layer can provide high friction coefficient, smooth surface layer.Thus,it can greatly improve the performance of pavement. Both the asphalt layer on old cement concrete pavement and new asphalt pavement, reflection crack is always one of the main reasons of pavement damage. Reasonable anti-crack measures has important significance to improve durability, saving resources and construction funds and promote the sustainable development of highway traffic construction pavement.In this issue, the local climate and traffic conditions are presented.We investigated and analyzed the damage types and damage reasons of asphalt overlay concrete pavement. We made a clear requirement on the detection of old cement concrete pavement and the key technology and key technics in this project. Based on previous research results.we proposed the scheme of preventing reflection cracks, the effective measures to increase the interlayer adhesion between the old and the new layer. Combined with the existing drainage facilities, effective drainage, convenient construction, minimize the cost of the pavement drainage were presented. According to the specific situation,we proposed the key parts of the construction,meanwhile,there are also schemes for bridges, traffic organization, environment protection,et. The study reached the following main conclusions:1) Guangdong Province has the long duration of high temperature:From May to October, the average temperature is above25℃,monthly extreme maximum temperature is above35℃. Monthly extreme maximum temperature greater than35℃is from May to October.The monthly extreme maximum temperature reached40℃in July and August.2) The annual rainfall mainly concentrated from May to August in Guangdong Province,the rainfall of the four months accounted for50-60%of the annual rainfall.The annual rainfall of the project site is approximate the same of Guangdong Province, that is the annual rainfall mainly concentrated from May to August.3) The asphalt overlay repairment is very necessary for this project, and it is economically and technically feasible.4) We investigated and analyzed the damage types and damage reasons of asphalt overlay concrete pavement. We made a clear requirement on the detection of old cement concrete pavement and the key technology and key technics in this project.5) To adopt fiberglass-polyester paving mat with good performance and easy construction as the measure to prevent the crack of cement concrete can effectively prevent and delay the reflection crack. In order to ensure the construction quality and preventing effect,we recommend to overspread.Otherwise, we should strictly control the construction technology and avoid polluting the fiberglass-polyester paving mat to ensure the effective bond of upper and lower structure layer. This issue has some reference value for similar research and application hereafter.