当比較已发表的那些报告中对于混凝土的描述时,时常会遇到这样的困难,即在一个报告中或兩个报告中会同样缺少某些有关的资料,特别在比较許多壩的混凝土时,更是如此。其原因一方面是由于它的特殊性引起的复杂多样性,例如采用特大的骨料,采用贫混凝土等;另一方面是由于其中某些項目終究是需 When comparing descriptions of concrete in published reports, it is common to encounter difficulties in reporting the same lack of relevant information in one or both reports, especially when comparing many dam concrete, Even more so. This is due in part to the complex and complex nature of its particularities, such as the use of extra-large aggregates, the use of lean concrete, etc .; on the other hand, some of these items are ultimately required