Tuesday, February 28, 2012

Chloride exposure of cracked concrete


Concrete specimens with controlled crack widths just started to be exposed to a chloride containing solution. This experiment will show how fast chlorides penetrate into concrete on the vicinity of the crack.
More results to be posted soon.

Photo by: B. Šavija

Tuesday, February 14, 2012

Chloride binding

As chlorides penetrate into the concrete, some of them are physically and chemically bound to the cement matrix. Therefore, only free chloride ions can promote the further penetration. Also, only free chloride ions are responsible for steel depassivation and initiation of the reinforcement corrosion. This effect needs, therefore, to be included in our predictions. The simplest way to do this is to consider binding as a linear phenomenon. Some authors suggested, however, that this assumption is not suitable for a wide range of chloride concentrations. Therefore, non-linear binding isotherms (mainly Freundlich and Langmuir) are often used. First trials with the both nonlinear and linear binding have been performed, and here are the results!



Monday, February 6, 2012

ESEM


Some interesting results were obtained on the ESEM on the past days. There is still a group of samples to be analyzed this week and results seem promising! Part of this work will be published soon. Keep in touch for more upcoming updates.
Adios