Loading Stresses in Two-Layered Cement Concrete Pavement Structure

摘要

At present time, a type of materials with fairly higher flexural rigidity (such as lean cement concrete, asphalt concrete, cement treated aggregate and lime-ash treated granular etc.) are widely applied to construct the base course of cement concrete pavement highway in China the objective of the study is to discuss approximate calculation of loading stresses in such kind of pavement structure, especially with a limited extension of base course, a simplified model of two-layered cement concrete pavement structure resting on Winlder foundation is then adopted, by using the finite element method, at critical location (in the middle of pavement longitudinal edge) the maximum loading stresses in two-layered cement concrete pavement structure are thoroughly analyzed, also, the effect of base extension is discussed, the results indicated that at critical location under either single-axle load or multi-axle load, with increase of the base extended amount the maximum loading stresses in concrete pavement reduce about 0-22%, but in base rise up from 0 to a limited value in extended direction, further, it is pointed out that the maximum loading stresses in general concrete pavement structure can be approximately expressed as the maximum loading stresses without base extension multiplying a so-called base extension modified coefficients. On the basis of extensive computation, a set of approximate formulas for calculation of loading stresses in two-layered cement concrete pavement structure are therefore provided, and the precisions of the formulas are discussed accordingly, however, the resultants will provide a sound basis for the amendment of the specification of cement concrete pavement design for highway in China.