二級(jí)公路畢業(yè)設(shè)計(jì)外文文獻(xiàn)(編輯修改稿)
2024-09-02 06:30 本頁(yè)面
【文章內(nèi)容簡(jiǎn)介】 radius of relative stiffness, f . Generally speaking, when the ratio L/E, where L is the length of slab, was greater than 5, transverse cracking occurred more frequently . This factor was further examined for different base types . It was found that stiffer base courses required shorter joint spacings to reduce or eliminate transverse cracking .Reinforcement The amount of steel reinforcement appeared to have an effect in controlling the amount of deteriorated transverse cracking . Pavement sections with less than % reinforcing steel often displayed significant deteriorated transverse minimum of 0 .1% reinforcing steel is therefore remended, with larger amounts required for more severe climate and longer slabs.Joint Orientation Conventional wisdom has it that skewed joints prevent the application of two wheel loads to the joint at the same time and thus can reduce loadassociated distresses . The results from the limited sample size in this study were ambiguous, but all of the nondoweled sections with skewed joints had a lower PSR than similar designs with perpendicular joints . The available data provide no definite conclusions on the effectiveness of skewing transverse joints for nondoweled slabs . Skewed joints are not believed to provide any benefit to doweled slabs.Load Transfer Dowel bars were found to be effective in reducing the amount of joint faulting when pared with nondoweled sections of parable designs. The diameter of dowels had an effect on performance, because larger diameter bars provided better load transfer and control of faulting under heavy traffic than did smaller appeared that a minimum dowel diameter of 1 .25 in . (32 mm) was necessary to provide good performance .Nondoweled JPCP slabs generally developed significant faulting, regardless of pavement design or climate . This effect was somewhat mitigated by the use of permeable bases. However, the sections in this group had a much lower number of accumulated ESAL, so no definite conclusions can be drawn yet .Dowel Bar Coatings Corrosionresistant coatings are needed to protect dowels from the adverse effects of moisture and deicing chemicals .While most of the sections in this study did not contain corrosionresistant dowel bars, those that did generally exhibited enhanced performance. Very little deteriorated transverse cracking was identified on these sections. In fact, one section in New Jersey with stainless steelclad dowel bars was performing satisfactoril
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