http://www.poison-frogs.nl/e030223.html
Flevopol is an emulsion of a hydrophilic network forming polymer ( like glue ) which is used in the construction industry to improve concrete floors and structures. It is a Dutch product but there should be enough similar materials around in the world that perform identical.
Since the experience in Holland lasts already several years and no bad effects have been seen on the frogs in these vivaria...
c'est un produit fabriqué en Hollande et qui sert à la construction de vivariums ... il semble que ce produit, après qq années d'utilisation est non toxique pour nos bestioles

autrement:
http://imageevent.com/audiomaster/40gallonhexagonThis is my first experience with the Dutch method of vivarium construction using "flevopol". It is an acrilate copolymer used as an additave in concrete to make it adhere better. But not in this case obviously. Flevopol is not avaliable in the USA, but I found a good substitute at my local ACE hardware. Its called Concrete primer & bonding additave and its made of Water and Acitate copolymer. When completely dried, it is rock hard and non-toxic.
encore une page ou il est fait usage du Flevopol ...