|
Title |
Evaluation on Sulfate Attack Resistance of Cement Matrix
|
|
Keywords |
sulfate deterioration factor(SDF); sulfate resistance; pozzolan reaction; latent hydraulic properties; ettringite; gypsum; Ca(OH)2 |
|
Abstract |
Compressive strength, sulfate deterioration factor(SDF) and length change of 5 types of mortars immersed in sodium sulfate solution were observed. As the results of tests, it was found that the sulfate resistance of blended cement mortars were superior to that of portland cement mortars. Pore volume with diameter larger than 0.1㎛ of 5 types of pastes indicated that the micro-structures of blended cement pastes were denser, due to pozzolan reaction and latent hydraulic properties, than those of portland cement pastes. The XRD, ESEM, EDS and TG analyses demonstrated that the reactants such as ettringite and gypsum were significantly formed in portland cement pastes. Besides, compared with the Ca(OH)₂ content of ordinary portland cement pastes immersed in water and sodium sulfate solution, the Ca(OH)₂ contents of fly ash blended cement and ground granulated blast-furnace slag cement paste were about 58% and 28% in water, and 55% and 20% in sodium sulfate solution, respectively.
|