Experimental and modeling study on the transient flow and time-dependent yield stress of superfine-tailings cemented paste backfill

The fresh superfine-tailings cemented paste backfill (SCPB) exhibits strong thixotropy, but quantification of the resulting transient flow (non-steady state) and time-dependent yield stress is lacking. In this study, a simple qualitative model was developed to describe the transient flow and time-dependent yield stress of SCPB. The effect of...

Effect of Activator Solutions on the Thixotropic Behavior of Alkali-Activated Slag Concrete

Alkali-activated material (AAM) is developed as a green alternative binder to replace Portland cement (PC) in the construction field. However, the large-scale application with AAM concrete is limited so far, with the insufficient knowledge of rheological behavior being a major obstruct. Thixotropy of concrete is of great interest, which can...

Effect of organic matter degradation in cohesive sediment: A detailed rheological analysis

Purpose<br/>The presence of organic matter in cohesive sediment results in the formation of clay-organic flocs, which eventually impart complex rheological behavior including shear-thinning, viscoelasticity, thixotropy and two-step yielding to mud. In this study, the influence of microbial degradation of sediment organic matter on the...

Impacts of shearing and temperature on sewage sludge: Rheological characterisation and integration to flow assessment

Accurate rheological characterisation of sewage waste activated sludge (WAS) is of high importance for downstream processing related to optimised sludge pumping and mixing, assessment of energy demands and overall process design. However, to elaborate rheological behaviour is often challenging under dynamic operational conditions in practice....

The Effect of Material Fresh Properties and Process Parameters on Buildability and Interlayer Adhesion of 3D Printed Concrete

The advent of digital concrete fabrication calls for advancing our understanding of the interaction of 3D printing with material rheology and print parameters, in addition to developing new measurement and control techniques. Thixotropy is the main challenge associated with printable material, which offers high yield strength and low viscosity....

Rheological analysis of mud from Port of Hamburg, Germany

Purpose: An innovative way to define navigable fluid mud layers is to make use of their rheological properties, in particular their yield stress. In order to help the development of in situ measurement techniques, it is essential that the key rheological parameters are estimated beforehand. Is there only one yield stress? In which shear rate...

Is density enough to predict the rheology of natural sediments?

Mud is a cohesive material which contains predominantly clay minerals, water, organic matter and some amounts of silt and sand. Mud samples can have complex rheological behaviour, displaying viscoelasticity, shear-thinning, thixotropy and yield stress. In this study, influence of organic matter on the rheological behaviour of different mud...

Experimental and mathematical characterisation of the rheological instability of concentrated waste activated sludge subject to anaerobic digestion

For a proper operational performance assessment of excess sewage sludge digesters in practice, a better understanding of waste activated sludge (WAS) rheological behaviour is important, especially regarding the low-shear and poor mixing zones in anaerobic digesters. The potential rheological instability of WAS with different total solids (TS)...