碾压混凝土孔隙结构与粉煤灰掺量的关系

采用吸水动力学和水银压入两种测试方法，对不同粉煤灰掺量的碾压混凝土砂浆不同龄期的孔隙参数进行了测试。当掺量不大于６０％时，总孔隙率不随掺量增加而增加，当掺量超过６０％以后，孔隙率随掺量的增加而急剧增加，从总孔隙率考虑，粉煤灰的最大允许掺量似可取为６０％，龄期愈长，孔隙的总体积愈小，本文系从孔隙结构来研究碾压混凝土的粉煤灰掺量，实际工程中确定粉煤灰的掺量还应从不同的角度考虑，粉煤灰和水泥的品种不同，

Relationship between void structure of RCC and its additive flyash quantity

By means of both water-absorbing dynamics and mercury intrusion method,tests are carried out on the void parameters of RCC mortar with different additive flyash quantities and various ages. When the additive flyash quantity is not greater than 60%,the total voidage of RCC does not increase with the increment of additive flyash quantity.When the additive flyash quantity is greater than 60%,the voidage increaseS steeply with the additive flyash quantity.Judged by the total voidage,the maximum allowable additive flyash quantity may reach 60%.The longer the age,the less the total volume of void is.In this paper,the problem in regard to additive flyash quantity is studied only from the point of view of void structure.However,for actual projects,the additive flyash quantity should be determined in consideration of various aspects concerned. The maximum allowable additive flyash quantity of RCC depends upon the assortments of both cement and flyash,and the appropriate additive flyash quantity should be determined by tests.