Pore Distribution and Durability of Cement Mortar by The Magnetic Resonance Imaging

摘要

The pore distribution in cement mortar, which is highly related to compressive strength and permeability, vary with water-cement ratios and curing periods. This study used magnetic resonance imaging (MRI) to observe the pore distribution. Compressive strength tests, the rapid chloride-ion permeability test, and electrical resistivity tests were performed to determine the influence of pore distribution on durability. The results reveal that lower water-cement ratios and longer curing periods contributes to fewer pores in mortar specimens. SEM images illustrated how this may be influenced by the rate at which the hydration product, C-S-H colloids, is generated. In addition, the results of durability testing indicate that porosity and compressive strength, total charge passed, and resistivity display linear relationships, as porosity increases, the total charge passed increases, resistivity decreases, and compressive strength declines. The linear regression determined that the R~2 of all relationships exceeded 0.90, thereby demonstrating the feasibility of applying MRI to assess the durability of concrete.