The present application relates generally to moving die rheometers, and more particularly to moving die rheometers that employ a variable eccentric cam. In one aspect, the eccentricity produced by the cam may be adjusted using shims of different thickness to alter the position of the post on the cam.

The use of recycled materials can have significant economic value. With the increasing quantity of recycled material used in viscoelastic materials, especially asphalt mixture, understanding how they interact with original materials to produce a mixture that performs successfully, becomes critical. Currently, the technology to determine the effect of additives on the performance of asphalt mixture is lacking. The present invention relates to a new unified methodology for mechanical testing of asphalt mixture and other viscoelastic materials that improves the current practice in speed, convenience, and accuracy. A new improved specimen mounting method on Dynamic Shear Rheometer (DSR), a new recovery method for fine portion of asphalt mixture, and three new tests for the performance of recovered material using DSR is disclosed. The new methods provide performance grading of asphalt mixtures that is new to the industry and provide necessary tools for determining the effect of recycled materials on performance.

A viscometer arrangement includes a detection system for detecting the proper placement of a rotor. An optical detection system may be used to detect the presence of an obstruction between the upper and lower dies while the upper and lower dies are in an open position.

The invention relates to a rotational shear rheometer (1) comprising a first plate (10), a first flexure (11) pivotally connecting the first plate (10) to a support (60), a piezoelectric element (40) extending along a longitudinal axis (L) arranged tangentially in respect of the first plate (10), wherein said piezoelectric element (40) is configured to elongate and/or undergo compression along said longitudinal axis (L), and wherein said first end (41) is mechanically coupled to said first plate (10), wherein said first flexure (11) comprises a first flexural element (12) and a second flexural element (13) non-parallel to the first flexural element (12), wherein the first flexural element (12) and the second flexural element (13) connect said first plate (10) to said support (60), extend radially in respect of the pivot axis (P) and intersect with the pivot axis (P), wherein said piezoelectric element (40) is further configured as a sensor capable of detecting a torque acting on said first plate (10). Furthermore, the invention relates to a method for determining mechanical properties of a sample using the rotational shear rheometer.

A method and apparatus is disclosed for compensating for a reduction of die cavity pressure in a torsional rheometer caused by shrinkage of the test sample. In one embodiment, a compliant member is placed in series with load-bearing components of the rheometer. This compliant member deflects when pressure in the die cavity is reduced resulting in the die cavity becoming smaller to increase the pressure within the die cavity.

The use of recycled materials can have significant economic value. With the increasing quantity of recycled material used in viscoelastic materials, especially asphalt mixture, understanding how they interact with original materials to produce a mixture that performs successfully, becomes critical. Currently, the technology to determine the effect of additives on the performance of asphalt mixture is lacking. The present invention relates to a new unified methodology for mechanical testing of asphalt mixture and other viscoelastic materials that improves the current practice in speed, convenience, and accuracy. A new improved specimen mounting method on Dynamic Shear Rheometer (DSR), a new recovery method for fine portion of asphalt mixture, and three new tests for the performance of recovered material using DSR is disclosed. The new methods provide performance grading of asphalt mixtures that is new to the industry and provide necessary tools for determining the effect of recycled materials on performance.

The use of recycled materials can have significant economic value. With the increasing quantity of recycled material used in viscoelastic materials, especially asphalt mixture, understanding how they interact with original materials to produce a mixture that performs successfully, becomes critical. Currently, the technology to determine the effect of additives on the performance of asphalt mixture is lacking. The present invention relates to a new unified methodology for mechanical testing of asphalt mixture and other viscoelastic materials that improves the current practice in speed, convenience, and accuracy. A new improved specimen mounting method on Dynamic Shear Rheometer (DSR), a new recovery method for fine portion of asphalt mixture, and three new tests for the performance of recovered material using DSR is disclosed. The new methods provide performance grading of asphalt mixtures that is new to the industry and provide necessary tools for determining the effect of recycled materials on performance.

A rheometer has a shaft, which is supported rotatably in a gas bearing. The gas bearing has a first bearing element (rotor) attached to the shaft and a second bearing element (stator) that surrounds the first bearing element (rotor) with a distance between the two, forming a bearing gap. At least sections of the second bearing element (stator) are made from a gas-permeable material, and gas is passed through them in such manner that a gas cushion is formed in the bearing gap, by which the first bearing element (rotor) and the shaft are supported without direct contact between the two. It is provided that the first bearing element (rotor) is also made from a gas-permeable material, at least in the areas that face the second bearing element (stator), and which the gas penetrates and forms a preferably static gaseous layer close to the surface as a result of the dynamic pressure or backpressure of the gas.

The disclosure provides a label-free viscosity-based analyte detection system using paramagnetic beads as an asynchronous magnetic bead rotation (AMBR) microviscometer. It is disclosed herein that the bead rotation period is linearly proportional to the viscosity of a solution comprising analytes surrounding the paramagnetic bead. Optical measurement of asynchronous microbead motion determines solution viscosity precisely in microscale volumes, thus allowing an estimate of analyte concentration. The results demonstrate the feasibility of viscosity-based analyte detection using AMBR in microscale aqueous volumes.

A method for determining the sticky point of powder samples includes introducing a sample into a first measuring part, placing a second measuring part above the first measuring part to delimit a sample chamber, using a motor to drive the measuring parts relative to one another, using a force application unit to exert a force on the sample normal to a rotational plane of the measuring parts, using a measuring unit to record a torque or shear stress of the sample between the measuring parts, using a temperature-control unit or oven to apply a temperature profile to the sample while measuring the torque or shear stress, and supplying recorded measured values of the torque or shear stress and the sample temperature at measuring points to an evaluation unit. The evaluation unit determines the sticky point from the measured values of the torque or shear stress and the temperature.