Study On Asphalt Concrete Overlay On Cement Pavement In Housing Estate

With the rapid development of the economy,citizens’ living quality is rising gradually.The amount of private cars is increasing exponentially,therefore the problem of urban road congestion is actually of increasing severity.Opening of gated community to social vehicles may not only alleviate the pressure of traffic of urban roads,but also improve its density of network.At the meantime,traffic volume of opening communities will definitely enlarge.However,those roads couldn’t bear such great traffic volume because their lower design standard and strength than urban roads.Thus,village roads should be overlaid and be widen.In addition,the major program is to overlay asphalt layer to the old concrete pavement.It is convenient and timesaving to conduct this program,and through which village roads can be strengthened.Considering the real situation,relying on the family courtyard No.21 of the Jinming campus of Henan University,the author firstly made a survey on the traffic volume and road condition.Then,he established the three-dimensional model of the old cement concrete pavement asphalt layer by using the finite element software and analyzed some parameter variables,such as the thickness and elastic modulus of the asphalt overlay,the thickness and elastic modulus of the cement stabilized macadam,the existence of the cracks in the concrete slab and so on.At the same time,he also established the numerical analysis model of the temperature field of the old cement pavement,through which influences of the scale of drop in temperature,layer thickness of asphalt overlay and the modulus of the cement stabilized macadam under the temperature field were analyzed.In addition,feasibility of the analog result was tested and verified by testing indoor shrink rule and comparing results of numerical simulation.Through field investigation of the community,the main diseases of the roads in the community are cracks,joints,surface peeling,exposed bones,pits and irregular maintenance.Through the scale test and the finite element simulation analysis,it is found that increasing the asphalt overlay and cement stabilized macadam thickness can effectively reduce the stress at the bottom of the asphalt overlay;The main stress of asphalt base can be reduced by increasing the elastic modulus of asphalt overlay;Overloading and greatly increasing the stress at the bottom of the asphalt overlay;The main stress at the bottom of asphalt overlay is the largest when there is eccentric load of crack,the second when there is positive pressure load of crack,and the smallest when there is no crack;Increasing the thickness of asphalt overlay can effectively reduce the temperature stress of asphalt overlay;Temperature variation has great influence on temperature stress of asphalt overlay;The temperature stress of asphalt overlay decreases with the increase of elastic modulus of cement stabilized macadam sandwich.