Application of bentonite in waterproofing of underground structures

Bentonite is a very important industrial material. Its dominant component is montmorillonite which makes at least 70% of its composition. Among various types of bentonite, the most commonly used is the sodium. It's characteristics, such as high swelling ability, the properties of thixotropy ( in a mixture with water it transfer into the gel), and high water absorption capacity (it can absorb 12 to 15 times the mass of water from the dry substance itself) give it a great advantage in geotechnical works as waterproofing material. This paper presents an application of bentonite carpets as an isolation agent in the reconstruction of the wine basement and the construction of the Roxanich Heritage Wine Hotel in Motovun. Bentonite carpet consist of bentonite membrane with montmorillonite content of at least 80%, in between two layers of geotextile, all bonded by thick stitching. Waterproofing system completes with tapes Waterstops RX 101, bentonite granules, bentonite Bentoseal paste and polymeric waterproofing. This system was used throughout the basement extending to five underground floors. It was proved to be an effective waterproofing solution, appropriately engineered for its operation in difficult ground conditions.