Can Concrete Be Waterproof?
Water and concrete aren’t friends. You need water to turn a mix into proper concrete, of course, but once it’s dry and cured, water has the ability to unmake what it’s made. It may take years or decades, but water can creep into the pores concrete and cause cracks thanks to the freeze-melt cycle and by slowly dissolving the lime-based cement that holds it together.
Because of this issue, a lot of time and effort is spent on keeping water from getting into concrete, especially foundations and basements of buildings. Recently, however, some materials scientists have been investigating ways to make itself more waterproof.
When it comes to materials, “hydrophobic” doesn’t mean that something fears water, it means that it can repel water. Nonpolar molecules, such as oil, grease, and petroleum, don’t mix with water, and so concrete with petroleum products mixed right in can potentially resist water much better than a normal one.
Supplementary Cementitious Materials
Instead of keeping water from entering the it’s pores, supplementary cementitious materials and other fine-grain materials like clay and talc fill in the pores. Clay pots are waterproof, after all, as are modern ceramics. The materials are cheap, but the problem is that fine-grain concrete needs more time to dry and cure since it’s also harder from the mixing process to leave.
Rather than form a barrier against water, some new mixes include special crystalline chemicals which absorb water and grow to block cement pores, making it harder for more water to get in. These mixes are the most expensive option, but also the most promising: the fact that the crystals grow in the presence of water means that they have the best coverage and can even seal cracks caused by the slow movement of the soil around the concrete.
If you’re in the process of building a new home for yourself or others in the states of Maryland, Pennsylvania, Delaware, New Jersey, D.C., or Virginia, AA Action Waterproofing can provide consultation services regarding concrete mixes and other waterproofing methods that go into protecting basements and foundations. We can also improve the waterproofing of existing basements, encapsulate crawlspaces, remediate mold, and even repair foundations.