During sorption, the microstructural evolutions of two different cement pastes (with water-to-cement ratios of 0.40 and 0.55) are studied via proton-nuclear-magnetic-resonance relaxometry. The water uptake test is performed for samples dried at 105°C under three different temperatures of 20°C, 40°C, and 60°C for the first twenty-six days of sorption. It is observed that the water went first to the larger pores before migrating to the finest ones. This behavior is accelerated with increasing temperature. The rate of water exchange between fine and large pores is estimated and found to increase with temperature for both studied mixtures. The activation energy corresponding to this water movement is calculated and found to be higher for the lowest water-to-cement ratio, owing its finer microstructure. Finally, the activation energy related to the local water transport in re-distribution from large pores to fine pores is calculated and found to be inferior to the experimental results, which can be explained by the dynamic microstructure not being considered in the classical theories.

在吸附过程中，通过质子核磁共振弛豫法研究了两种不同水泥浆（水灰比分别为0.40和0.55）的微观结构演变。吸水测试是针对在最初的26天中在105°C下在20°C，40°C和60°C的三种不同温度下干燥的样品进行的。可以观察到，水先迁移到较大的孔，然后才迁移到最细的孔。随着温度的升高，这种行为会加速。估计和发现细孔和大孔之间的水交换速率随温度的升高而增加。计算出与该水运动相对应的活化能，并且由于其更细的微观结构，对于最低的水灰比，其活化能更高。最后，