Clay-cement mix with reinforcing fibres for diaphragm walls

Diaphragm walls constructed by the slurry trench method are one of the most frequently used and proven possibilities to encapsulate landfills or old industrial sites. Thus, contaminant propagation into ground water may be hindered in cases where insufficient or non-existent bottom sealing capacity exists. In the case of external loading after the execution and hardening of the wall, the diaphragm wall's capacity to withstand these mechanical solicitations without a decrease in performance must be verified. As the most recent research results have shown, in the case of very small deformations, clay-cement mixes for diaphragm walls are only able to withstand low tensile stress levels. In the following article, research results obtained for fibre reinforced samples will be presented. Samples reinforced with polyvinyl alcohol fibres showed increased tensile strength, higher unconfined compressive strength and higher triaxial shear strength. The principal advantage of fibre reinforcing is most probably due to the fact that if tension resistance is exceeded due to bending, the formation of gaping cracks over the entire wall section is hindered.