DUCTILITY CHARACTERIZATION OF CUTOFF WALL WATER/CEMENT/BENTONITE MIXTURES

Abstract

Following the increased use of sealing structures built in order to isolate historically polluted sites or to repair infiltrations inflicted to the levee of dams, it emerged the need to choose the right materials for constructing barriers using cutoff wall technique. The objective of this paper is to assess the range of suitable material combinations (water, cement and bentonite) in order to attain proper compressive strength, permeability and ductility requirements of such a structure. This paper proposes the representation of various mixtures on a ternary diagram, where the components are used as mass percentages. Since the influence of excessive values of various components have on the physical and mechanical behavior of the samples, the study domain was limited to an area that represents feasible mixtures. The laboratory testing program aimed at studying the variation of the material ductility, expressed in terms of tangent elastic modulus at origin and maximum axial strain at failure. Other parameters previously studied (compressive strength, viscosity and permeability) are used for property correlation.