Study on the Load Carrying Mechanism in Shear of Composite Slabs Under the Repetition of a Wheel Load.

(1)车轮跟踪装置：装载车轮四周包覆聚氨酯橡胶，直径410mm，直径100mm，接触面积100 × 200mm^2。车轮被证明可以抵抗跟踪施加的3.5tf负载强度。研制的仪器满足了工程的要求。(2)钢筋混凝土板的静力和疲劳荷载试验：1989年用上述装置对100cm × 160cm × 6cm的钢筋混凝土板进行车轮跟踪超过100cm的疲劳试验结果与1990年相同形状的钢筋混凝土板在160cm以上的车轮跟踪下的疲劳试验结果有很大差异。小型钢筋混凝土板的疲劳特性对轨迹速度和轨迹长度等条件较为敏感。(3)叠合板的静力破坏性能：对12块带头螺柱连接的混凝土与薄钢板叠合板进行了静载试验。结果表明，仅在其周围边缘布置螺柱的板出现粘结滑移破坏模式，而在整个界面布置螺柱的板则出现冲剪破坏模式。(4)车轮跟踪下复合板的疲劳强度：利用车轮跟踪仪对复合板进行疲劳试验，得出以下结果：1)复合板的破坏模式与静载下的破坏模式相似。2)采用格子薄钢板可显著提高疲劳强度。然而，它仍然需要一些补充测试来得出定量结果。(5)薄钢板抗剪粘结试验：在约束应力控制下，对19个不同螺柱布置或格子钢板的试件进行了拉出剪切试验。它可以揭示复合板中薄钢板的粘结强度和滑移行为。

(1) Wheel Tracking Apparatus : The loading wheel covered around with polyurethane rubber had 410mm in diameter, 100mm with and 100 x 200mm^2 contact area. The wheel was proof against the tracking imposed 3.5tf load intensity. Thus the apparatus developed was satisfactory for the requirement of the project.(2) Static and Fatigue Loading Test of Reinforced Concrete (RC) Slabs : The results from fatigue tests using the above apparatus in 1989 of the RC slabs (100cm x 160cm x 6cm) subjected to wheel tracking over 100cm trace length differed greatly from those in 1990 of the slabs having the same shape under the tracking over 160cm. The fatigue characteristics of small scaled RC slabs were sensitive to the conditions such as tracking speed and its trace length.(3) Static Collapse Behavior of Composite Slabs : The static loading tests of 12 composite slabs consisting of concrete and thin steel plate with headed stud connectors were carried out. It could be found that the slabs arranged the studs only near their surrounding edges gave bond slip failure modes, while ones having the arrangement over the whole intersurface did punching shear modes.(4) Fatigue Strength of Composite Slabs Under Wheel Tracking : The fatigue tests of composite slabs using the wheel tracking apparatus could draw the following results : 1) The failure modes of the slabs were similar to ones observed under static loading. 2) The use of checkered thin steel plates could improve the fatigue strength remarkably. However, it should still require a number of supplementary tests to lead to quantitative results.(5) Bond Against Shear of Thin Steel Plates : 19 specimens with variation of stud arrangements or checker steel plates were tested under a pull-out shear loading in control of confinement stress. It could reveal the bond strength and the slip behavior of thin steel plates in the composite slabs.