CONCRETE

[:ru]фон Маубайге К.[:en]von Maubeuge[:] [:ru]NAUE GmbH & Co. KG, Эспелькамп-Фистель, Германия[:en]NAUE GmbH & Co. KG, Espelkamp-Fiestel, Germany[:]

[:ru]Шлее Ю.[:en]Schlee, J.[:] [:ru]NAUE GmbH & Co. KG, Эспелькамп-Фистель, Германия[:en]NAUE GmbH & Co. KG, Espelkamp-Fiestel, Germany[:]

Alitinform №3 (35) 2014 г. 66-77 p.

Abstract

Geosynthetic Сlay Liners (GCLs) are mostly needlepunched, fibre-reinforced composites that combine two durable outer layers and an intermediate uniform core of high swelling powder sodium bentonite clay, which acts as the barrier component. These uniform needlepunched GCLs form a direction independent shear strength transferring sealing barrier. When the bentonite core hydrates with fresh water, the bentonite swells and forms a low permeability gel layer, which outperforms traditional, thick compacted clay liners, due to the bentonite´s ability to self-seal and re-heal. Further features of GCLs are (but are not limited to):

• High internal shear strength for steeper slopes;
• Durable geotextiles for the encapsulation of bentonite and long-term performance;
• Excellent interface friction values;
• Uniform bentonite distribution and immediate swelling for better long-term sealing performance;

Low material costs and cost effective in installation.
GCL improvements, since the invention of needlepunched GCLs in 1987 and contribution to the under-standing and adoption of GCLs in engineering and construction, have been numerous. After adding a heat-treating process to improve internal shear resistance and the self-sealing bentonite treated over-laps, the next phase for GCLs is a firmly attached durable polyolefin polymer coating on the slit-film woven geotextile component. Now GCLs can challenge particular site conditions where the use of GCLs was limited up to now and improve the performance of GCLs. The success of needlepunched GCLs has been proven in approximately 100 million square meters of installed material since 1987 and will further show the same success but to make a GCL more effective, better performing, safer and longer lasting, the polymer coating is a way to go and gives GCLs the winning performance. This paper will discuss this new GCL technology, the advantages of the polymer coating added to the GCL, the current test results, the applications where such GCL products are ideally used and the necessary design considerations.

Key words:

Geosynthetic Clay Liners (GCL); geotextile; Multicomponent GCLs; polymer coated, needlepunched GCLs