土木工程专业英语第五章教案分析.ppt

* * * * * * * * * * * * * * * * * * * * * * * Unit 5 Road Engineering The report estimates that urban drivers pay an average of $746/year on vehicle repairs while the average US motorist pays about $335/year. 该报告估计，城市司机平均在汽车修理中支付约746美元/年，而这一数值在全美则约为335美元/年。 Unit 5 Road Engineering In contrast, the average motorist pays about $171/year in road maintenance taxes (based on 600 gallons/year and $0.285/gallon tax). 相比之下，一般的司机支付约171美元/年的道路维修税（养路费）（上述数据是基于600加仑/年，0.285美元/加仑税计算而来）。 Unit 5 Road Engineering Distress and serviceability loss on concrete roads can be caused by loss of support due to voids beneath the concrete pavement slabs. 混凝土道路的损害与服务性能的降低可以归咎于混凝土路面板之下存在的空隙所引起的支撑力不足。 Unit 5 Road Engineering The voids usually occur near cracks or joints due to surface water infiltration. The most common cause of voids are pumping, consolidation, subgrade failure and bridge approach failure. 空隙通常发生裂缝或表面水分渗入之处的附近。空隙的最常见危害是动水压力，固结，地基病害以及引桥病害。 Unit 5 Road Engineering Slab stabilization is a non-destructive method of solving this problem and is usually employed with other Concrete Pavement Restoration (CPR) methods including patching and diamond grinding. 路面板的加固是解决这个问题的一种无损方法，此外，该方法也通常与其他混凝土路面修复方法（如坑槽处理、切块修复）一同被应用。 Unit 5 Road Engineering The technique restores support to concrete slabs by filing small voids that develop underneath the concrete slab at joints, cracks or the pavement edge. 该技术可以阻止混凝土路面板下方渗水处、裂缝处以及路面边缘等布满微小孔隙处的发展。 Unit 5 Road Engineering The process consists of pumping a cementitious grout or polyurethane mixture through holes drilled through the slab. The grout can fill small voids beneath the slab and /or sub-base. 这个过程包括将水泥胶浆或者与聚氨酯的混合物通过路面板的钻孔压入.水泥胶浆可以填补面板板下方和/或底基层的小空隙。 Unit 5 Road Engineering The grout also displaces free water and helps keep water from saturating and weakening support under the joints and slab edge after stabilization is complete. 灌浆同时将自由水挤出，避免了加固之后水分的饱和以及接缝、路面板边缘处轻度的不足。 Unit 5 Road Engineerin