Multilayer, multifunctional textile composite for the hydro-insulation of concrete structures

Abstract

Subject of the doctorate thesis is a “Multilayer, multifunctional textile composite for the hydro-insulation of concrete structures” which constitutes a scientific approach to novel hydro-protection textiles-employing systems primarily suitable to outer horizontal concrete structures. The new method is founded on textile materials with varied functional structures that nowadays are omnipresent in technical applications. Textile materials, aside of they grand role in apparels, have found wide avenues of application in various technical segments. My professional experience and knowledge derived from technical literature have given rise to the following formulation of my thesis: “A chance exists of preparing a novel multifunctional damp-proof composite that would provide: (1) a reliable unmanned curing of the concrete in new built horizontal, outer architecture elements, (2) a permanent, faultless anti-water protection in exploitation”.

Demanded of the composite is an excellent barrier function and reliability in the exploitation of the structure as well as a substantial shortening of the construction or renovation works which in turn leads to lower costs involved. The nonwoven composite provides an unmanned curing of the concrete, while its drainage properties ensure, as shown in experiments, a proper run of the curing required in the process of concrete hydration. In the specific case the composite is expected that its structure would provide an efficient drainage which permits the evacuation of excessive unbounded moisture during the concrete maturation. Full barrier properties are maintained as well as the property of a slow plastic deformation (settlement) which causes a decrease of the composite drainage mass porosity by the pressure of outer layers (oversite, subsoil). The composite comprises three layers: Upper layer It is a geotextile nonwoven to play the role of protecting the barrier layer against mechanical damage during the spreading of the composite and casting of the oversite layer. Central layer It is a thermoplastic polyethylene film which, after its consolidation with the upper and bottom layer, constitutes a full water barrier for the composite. Bottom layer It is a geotextile nonwoven with excellent drainage properties imparted by high elasticity and adequate porosity.

Role of that layer is to evacuate excessive water that remained unbounded with cement, and to provide water conditions on the surface of the concrete construction like for a cured concrete in its maturation period. The elaborated nonwoven composite provides a high hydro-insulation barrier demanded in the construction of balconies, terraces and loggias, and, at the same time, ensures the retention of water in amount indispensable for concrete maturing. In current practice, the damp-proof layers of the horizontal concrete constructions are put in place after the completion of the concrete maturing. It requires, in the construction works, a quite long time; the process is troublesome and often underestimated by the building people. The proposed composite can be laid onto the concrete construction short after casting. It is, however, recommended to do it after 24 to 48 hours after the concrete has been cast. The concrete construction shall acquire certain strength in that time to protect it against damage when the composite is spread upon it. An oversite layer may be spread promptly on the prepared composite layer. The proposed technology shortens the construction works by 3 to 4 weeks. The method for the damp-proof insulation with the use of the prepared barrier composite and the material itself have been applied for a Polish patent. Noteworthy is that the technology is genuinely environment friendly since, with the new process, the use of the hazardous tar board and solvents is abandoned.

The new method of damp-proofing with the use of a multilayer, multifunctional textile composite was eventually verified on a balcony built for that purpose on one of the buildings of the Institute for Sustainable Technologies where the examination was completed. The obtained results fully confirmed the barrier properties of the composite and its unchallenged suitability to the maturing and curing of the concrete, and to a reliable functioning in real climatic conditions.