pavement permanent deformations due to lack of shear strength in mixture are a major reason of rutting. any simple test to determine mixtures resistance to permanent deformation isn’t distinguished in the 1st level of superpave mix design method and prevalent methods for evaluating mixture rut resistance are expensive and time-consuming. two aggregate types, gradations, asphalt cements and fill...

The dynamic and static yield stress of fresh cement mortar were measured in a rotational rheometer with a vane geometry using shear rate and shear stress-controlled protocols, respectively. Through a shear rate-controlled steady-state protocol, the equilibrium flow curve is measured and fitted with the Bingham model to obtain dynamic yield stress. A negative slope in the equilibrium flow curve,...

the research was conducted in order to determine the bending stress, young’s modulus, shearing stress, and shearing energy of safflower stalk as a function of moisture content and stalk region. the bending forces were measured at different moisture contents and the bending stress and the young’s modulus were calculated from these data. for measuring the shear forces, the stalk specimens were se...

[1] Conditions for shear and compaction localization are examined for stress states on an elliptic yield cap in the space of Mises equivalent shear stress t and mean normal compressive stress s. Localization is predicted to occur when the slope of the hydrostatic stress versus inelastic volume strain curve falls to a critical value kcrit. When applied to the standard triaxial test, the analysis...

We study the rheological behavior of concentrated granular suspensions of simple spherical particles. Under controlled stress, the system exhibits an S-shaped flow curve (stress vs shear rate) with a negative slope in between the low-viscosity Newtonian regime and the shear thickened regime. Under controlled shear rate, a discontinuous transition between the two states is observed. Stress visua...

The present study describes entrainment characteristics of bed material into debris flow, based on flume tests, numerical and dimensional analyses. Flume tests are conducted to investigate influences of bed sediment size on erosion rate by supplying debris flows having unsaturated sediment concentration over erodible beds. Experimental results show that the erosion rate decreases monotonically ...

The effect of flaxseed gum (FG) on the rheological and nonlinear stress response behaviors of mixed soy protein isolate (SPI)-flaxseed gum (FG) dispersions were studied. Results showed that the viscosity of the SPI-FG mixed dispersions increased significantly with increase in the FG concentration. Both the shear stress and the apparent viscosity values as a function of shear rate were fitted we...

Pelite is a polyethylene closed cell foam commonly used as an interface material in prosthetics. Both normal and vacuum-formed Pelite were tested under compression and under shear loading. For shear testing, the results were not significantly different for normal and vacuum-formed Pelite. For normal Pelite, the slope of the stress-strain curve was 1.17MPa (+/- 0.14) while for vacuum-formed Peli...

There are strong medical motivations to measure changes in material properties of tubular organs, in vivo and in vitro. The current approach estimates hoop stress from intraluminal pressure using the Laplace law and identifies 'elastic modulus' as the slope of a curve fitted hoop stress plotted against strain data. We show that this procedure is fundamentally flawed because muscle and other sof...

To study the effect of aging on deformability of an erythrocyte, rheological measurement has been performed after exposure to a shear field in vitro. Deformability was evaluated with shear stress responsiveness and with critical elongation calculated from an exponential curve between an elongation index and shear stress. Human erythrocytes were classified according to their density by a centrif...