More than 100 inground outdoor swimming pools and integral spas—constructed using reinforced shotcrete shells faced with nominal 12.5-mm-thick (½-in.-thick) intimately bonded white mortar veneer—had cracked after a few years of use.
The high pH of uncarbonated concrete (minimum 12.5) keeps steel from corroding when chloride contents are less than about 0.20% by portland cement mass.
Some metals usually get along fine in portland cement mortar and concrete. Some do not, for some it depends. Iron and steel are among the first kind.
When we discussed hydration last month, it dealt mostly with calcium hydroxide (Ca(OH) or CH), which seemed like a good way to introduce the subject—after all, calcium hydroxide constitutes about 20% to 25% of the portland cement paste.
We all have passions—portland cement's passion is water. With water, it becomes another material that possesses a myriad of physical and chemical properties.