Bentonite Waterstops:advantages And Disadvantages

Bentonite Waterstops:advantages And Disadvantages

By:


Bentonite waterstops are used for the waterproofing of construction joints in water excluding or water including structures such as:



- dams



- basements



- water tanks



- swimming pools



- culverts etc.



Bentonite waterstops are based on natural sodium bentonite (usually montmorillonite) entrapped in a polymer matrix (usually of a highly molecular polyisobutylene rubber).



The invention of bentonite waterstops in 90's was a real revolution for construction joints waterproofing.



The philosophy of the product is simple: On contact with water the bentonite will expand in a controlled way seal and perfectly waterproof all construction joints in concrete. The sealing will resist pressures as high as 5at.



There is no comparison to the old method of waterproofing the joints with PVC waterstops (Please check the relevant article on this site).



In Greece a stunning 80-90% of joints waterproofed with PVC waterstops will fail. The corresponding percentage for bentonite waterstops is less than 10%.



I will confess, however, that Greek technicians don't know how to install a PVC waterstops in an appropriate way.





STRONG POINTS OF BENTONITE WATERSTOPS





1. Very easy application. Can be effected with the help of a special adhesive/primer - we use MS Polymers - or by nailing. Sometimes we use special wire mesh profiles.



2. Splicing is not a problem for bentonite waterstops. Just butt stripe ends firmly together - 10cm is OK - and the continuity of the waterproofing is ensured.



3. Their functional life is not les than that of the project. Swelling and shrinking are infinitely reversible procedures.



4. They exhibit a self-injecting effect a.k.a. they penetrate every crack and cavity.



5. They are suitable for salt and mineral water.





WEAK POINTS OF BENTONITE WATERSTOPS





1 Bentonite waterstops are not suitable for the waterproofing of expansion joints. Here the only option is still PVC waterstops.



2. Many bentonite waterstops suffer from premature swelling in case of rain or exposure to ground waters.



There are patented versions, however, with delayed swelling. Make sure that you use the right product.



3. If not properly fixed, the waterstops will be displaced from the concrete.



4. If cement paste infiltrates between the weathered concrete and the waterstop the latter will be short circuited and waterproofing will be at stake.





Conclusion: Bentonite waterstops are here to stay. With the proper attention they can offer easy and reliable waterproofing solutions.





Chris Strogilis



Civ. Eng. - MBA - DipM



http://maconwaterproofing.blogspot.com/

About the Author:
http://www.macon.gr/index.asp?lid=en

http://monosimacon.blogspot.com


http://maconwaterproofing.blogspot.com



Article Originally Published On: http://www.articlesnatch.com


Tags: , ,

|

Loading...
Related....
Videos...

Recent Home-Improvement Articles

Comments

Still can't find what you are looking for? Search for it!

Loading

Site Navigation:

Copyright 2005-2011 ArticleSnatch, LLC - All Rights Reserved.
Privacy Policy | Terms of Service.