Abstract
Pore structure of hardened cement paste is believed as a decisive factor determining properties, such as durability, of cement based materials. And it is pointed out that pore structure and frost resistance of hardened cement paste is remarkably changed by drying or wetting - drying curing. This paper discusses the influence of environmental conditions, such as drying or drying - wetting cycles on the changes of pore structure and frost resistance of mortar.
In this study, pore structure of mortar was analyzed by Mercury Intrusion Porosimetry and under water weighing. And frost resistance of mortar was examined by CIF method.
By drying or drying - wetting curing at high temperature, pore structure of mortar was coarsened and the pore volume with a diameter ranging from 40 to 2000nm was increased. Frost resistance of mortar sharply decreased by drying or drying - wetting curing at high temperature. The durability factor of mortar was rapidly decreased as the pore volume with a diameter ranging from 40 to 2000nm was increased. And from the results of further analysis of mortar pore structure, it was cleared that the volume of ink bottle type pore was increased as the pore volume with a diameter ranging from 40 to 2000nm increased.
