较大偏高岭土掺量下水泥基材料的水化和性能

Hydration and Mechanical Properties of Cement-Based Materials with High Use Level of Metakaolin

测定了较大偏高岭土(MK)掺量下偏高岭土-水泥(MK-C)砂浆的抗压强度、MK-C净浆的水泥相对水化程度和累计放热量,探讨了净浆化学结合水量,砂浆抗压强度与净浆累计放热量的关系.结果表明:考虑了"稀释效应"、MK表面成核效应及火山灰效应的有效接触表面积模型可定量表征MK-C砂浆的抗压强度;水泥相对水化程度随MK掺量的增加而逐渐增大,随龄期的延长而先增加后降低;随MK掺量的增加,净浆最大累计放热量逐渐降低,最大累计放热增量逐渐变大,净浆化学结合水量与累计放热量在养护早期和后期存在不同的线性关系,砂浆早期抗压强度与净浆累计放热量线性相关.

To study the relations between the mechanical properties and hydration of cement-based materials with high use level of metakaolin （MK）, compressive strength of metakaolin-cement （MK-C） mortars and the relative hydration degree of cement in MK-C pastes as well as hydration heat were measured. The relations between non-evaporable water amount, compressive strength and hydration heat were also investigated. Re- sults show that compressive strength of MK-C mortars can be quantified by the effective contact surface mod- el, in which the dilution effect, the heterogeneous nucleation effect and the pozzolanic reaction are all taken in- to consideration. The relative hydration degree of cement increases as the use level of MK increases while it firstly increases and then decreases with increasing aging time. The max hydration heat decreases and heat increment increases as the use level of MK increases. The linear relation between accumulated hydration heat and non-evaporable water amount at the early ages is different from that at the late ages. And a linear relation exists between accumulated hydration heat and compressive strength at the early ages.