Only limited determinations of these coefficients have been made for low-density concretes .
只有这些系数的限制了的确定值是用于低密度混凝土的。
For most regular concretes , the direct t ensile strength may be estimated as .
对最普通的混凝土而言，直接抗拉强度可估计为。
This paper earnestly analyzes the problems of the study style existing in professional colleges and the causes so as to submit the concretes measure and suggestions used to strengthen the construction of study style .
