MECHANICS EFFECTIVENESS AND ANALYSIS OF THE CONSTRACTION JIONT ADDED DOWEL BAR ON OLD CEMENT CONCRETE PAVEMENT

In order to study the comprehensive effectiveness induced by adding dowel bars, we add dowel bars to contraction joints on old cement concrete of expressway pavement, and construct different testing roads in accordance with different design plans. The test indicates that the transfer coefficient of contraction joints without adding dowel bars is 0.2~0.4, which is improved to 0.7~1.0 when dowel bars is added, and the transfer capacity is improved 2~5 times. The average deflection value of a direct loading concrete board falls from 0.587mm to 0.331mm, reduced about 1.8 times. The three-dimensional model of adding dowel bars to old cement concrete pavement by ANSYS finite element analysis was established, made a simulation comparison to 5 kinds of contraction joint design program for broken and no broken boards respectively. Research indicates that it is quite economic and reasonable to add 8 dowel bars to a contraction joint section on old cement concrete pavement when the diameter is 28mm and spacing 26cm, adding dowel bars will bring enormously benefits, thus provides a theory basis for the economical and reasonable transformation design plan.