Author(s): Mohsen Ebrahimi; Ana Maria Ferreira da Silva
Keywords: Bed roughness; durability; fixed bed; hardening; movable bed; sand–cement mixture; shear strength
Abstract: A method to fix movable beds in river-related laboratory research or physical model studies is proposed and investigated. The motivation was to develop a method that would: (1) not involve the use of harsh chemicals and (2) ensure that the granular roughness of the original movable bed was maintained. The method involves coating the surface with a mixture of sand and Portland cement. Laboratory tests were conducted to determine the amount of cement, and investigate the best method of application, effect on roughness, shear strength and durability. It is found that the method can be used to fix both flat and deformed beds. The method is particularly effective for sands up to 1.1 mm, when it is possible to ensure that the granular roughness of the fixed bed is comparable to that of the movable bed by merely using in the coating mixture a coarser sand than the original one.