BM-Valla verifying their concrete mixes based on new Swedish regulations about freeze-thaw testing

Einar Einarson from BM-Vallá, one of the Ar2CorD project partners, has long experience with freeze-thaw durability testing, as this property of concrete is indispensable in Icelandic climate conditions. Presently, he follows standard SS 137244, but after a discussion with Jonas Carlswärd from Heidelberg Materials Sweden AB, he started to be concerned about the impact of carbonation on the freeze-thaw performance of the concrete they produce. In the new national annex of EN206, the SS 137003 describes a new curing procedure for concrete in the XF4 exposure class with clinker content between 65 and 80 %. The new aspect is the addition of carbonation during the curing period.

Low-carbon concrete might be more susceptible to degradation and through testing is required before its distribution to customers. Therefore, Einar decided to prepare a series of 4 different mixes with Portland cement or fly ash cement and variable water/cement ratios. Properties of fresh concrete were checked, including the measurements of air content that has a significant influence on freeze-thaw performance. Samples for compressive strength and freeze-thaw testing were prepared. The innovative aspect of the testing program is exposure to four different curing types of samples for freeze-thaw testing, including prolonged curing in field conditions (by sea or road).

The test plan seems very interesting, and its results will be presented during the Ar2CorD seminar scheduled for the first part of 2024.