Study On Structure Design Method And Typical Structure Of Asphalt Overlay Paved On Old Cement Concrete Pavement

The current design criterion of old cement concrete paved with asphalt overlay structurecan not control pavement’s performance very well,there is still defects in overlay structuredesign method. In addition,the reflection crack prevention measures in current design standardhave not given their application condition and range,and have be lack of specificrequirements.This paper study on overlay structure design methods based on old cementpavement disease charctristic,and proposed some concrete prevention measures of reflectioncrack.The main acchivements are as follows:1、Research in overlay structure design method based on old concrete slab length, make theconclusion that when the old concrete slab crack is longer,its economic and reasonableoverlay thickness is between14~18cm,and if the crack is shorter,it is unfavorable to paveasphalt overlay.2、Study on overlay structure design method based on faulting amount of slab ends,obtained the conclusion that the increase of slab ends faulting amounts,will make the aspaltoverlay bottom stress significantly larger.So,we should take measures to minimize the faultingamount of slab ends,and preferably not more than0.5cm.3、Study on reflection crack prevention measures of asphalt overlay,make the conclusionthat sress absorbing layer is btter than sress absorbing membrance,and the best thicknessof sress absorbing layer is between2.5~3cm,the optimum module range is300~500MPa,which will have significant effect of anti reflection crack.4、Through analysis the warm-wet climate and traffic characteristics of GuangdongProvience, proposed the typical asphalt overlay map that used in Guangdong region.