8 Pages

Strains and stresses in concrete due to saline and non-saline freeze-thaw loads

V. Penttala

ABSTRACT: The strains in cylindrical concrete test specimen (ϕ 65 mm, h = 190 mm) were measured at the surface and at the middle axis of the cylinder during cyclic freeze-thaw loads. Concrete possessed compressive strength of 25 MPa and both air-entrained (air content 6.0%) and non-air-entrained (air content 2.2%) concretes were tested. Prior to the freezethaw cycles, half of the specimen was cured under water in a 3% NaCl solution for six weeks. The other half of the specimen was cured under non-saline water. During the four freezethaw cycles temperature varied between + 7°C and −37°C Relative humidity and temperature in the test chamber and in two locations inside concrete was measured during the test. These locations were situated at the middle axis and at the half radius distance inside concrete. The freezing-induced axial compressive concrete stresses and the pore water tensions in the specimen were calculated.