Porengrössenverteilung von Mörteln nach lagerung im wasser und in einer chloridlösung

For the purpose of the investigation of relations between the chloride diffusion into concrete and the pore structure of the hardened cement paste, the porosity of cement mortars were examined. The mortar specimens of four cements with a graded blast-furnace slag content (0 to 79 % by mass) prepared at w/c ratios 0,50 and 0,70 were stored in a concentrated NaCl solution and water respectively up to 2 years. The pore size distributions of the mortars were determined by means of mercury intrusion porosimetry and water absorption. The samples stored in water showed a relationship between the percentage of small (gel) as well as great (capillary) pores and the slag content of the cement and the w/c ratio of the mortar. After 6 and 12 months, the storing in the chloride solution effected an alteration of the pore structure reducing the total and gel pore volume and increasing the capillar pore volume. Later, the gel pore fraction was near to that of the specimens stored in water.