A device for measuring shear properties of asphalt mixtures includes a machine for testing the material strength, equipped with an operational frame, fixing elements and driving mechanism, the machine including a steel socket equipped at at least one of a bottom and a top edge thereof with an inner flange to accommodate a testing specimen, the testing specimen having a central open hole, and a steel insert adapted to be inserted into the open hole in the testing specimen, the steel insert being equipped with a rim at at least one of an end thereof at the top edge of the steel socket and at end thereof at the bottom of the steel socket, while a size of a clearance between the inner flange and the rim being between 5 to 60 mm, and the steel insert being equipped with elements for fixing to clamping elements of the device, and measuring probes being connected to the steel insert.

Systems and methods in accordance with embodiments of the invention determine the effective toughness of a given material, and also implement materials possessing improved effective toughness values. In one embodiment, a method of determining the effective toughness of a material includes: causing a crack to propagate through the material; where the relative constant velocity and the relative overall direction are prescribed and maintained for the duration of the propagation of the crack through the material; measuring the energy release rate of the crack as it propagates through the material; and defining the effective toughness of the material as the maximum value of the measured energy release rate.

An apparatus for applying a force to a specimen is provided. The apparatus comprises: an output rotatable member comprising a plurality of connection points; a plurality of rigid connection means, each comprising a first end and a second end, wherein the first end of each connection

means is pivotably coupled to one of the plurality of connection points of the output rotatable member; a plurality of guide members; and a plurality of specimen holders, each slidably mounted to one of the guide members and pivotably coupled to the second end of one of the plurality of connection means.

A device for measuring shear properties of asphalt mixtures includes a machine for testing the material strength, equipped with an operational frame, fixing elements and driving mechanism, the machine including a steel socket equipped at at least one of a bottom and a top edge thereof with an inner flange to accommodate a testing specimen, the testing specimen having a central open hole, and a steel insert adapted to be inserted into the open hole in the testing specimen, the steel insert being equipped with a rim at at least one of an end thereof at the top edge of the steel socket and at end thereof at the bottom of the steel socket, while a size of a clearance between the inner flange and the rim being between 5 to 60 mm, and the steel insert being equipped with elements for fixing to clamping elements of the device, and measuring probes being connected to the steel insert.

A device for performing a mechanical four-point bending test on a test piece and to a method for using one such device. The device comprises: a) structure for holding a first end of the test piece (27; 127; 28; 128) and structure for holding a second end of the test piece (30, 31); b) traction wire (25) and converting structure (16, 116) for converting a translational movement of said traction means into a rotational movement; c) conversion structure (26; 27; 126; 127) for converting said rotational movement into bending deformation of the test piece. Said conversion structure comprises at least one first Cardan joint (26; 126), connected to the structure for holding the first end of the test piece.

A device and method for applying an internal pressure and resultant hoop stress to a hollow cylindrical object, such as a test cylinder, utilizing an expandable cylinder and upper and lower conically shaped rams. The device is inserted into a test cylinder, and when a compressive force is applied to the upper and lower conically shaped rams, the rams move vertically into upper and lower conically shaped cavities of the expandable cylinder. The sloped inner surfaces of the conically shaped upper and lower cavities convert the vertical motion into an outward radial motion, applying an internal pressure and resultant hoop stress to the cylindrical object.

A bi-axial testing apparatus, system and method may be used with known uni-axial material testing machines to perform biaxial displacement control (e.g., compressive and/or tensile) testing on a specimen. As such, the apparatus, system and method may be capable of providing bi-axial compressive or tensile loads with uni-axial motion and only one actuator. The specimen may be a cubic specimen including, without limitation, 3D printed cellular materials, composite materials, foams, bio-medical materials, and the like. The apparatus generally includes a first or top fixture forming a first re-entrant surface and a second or bottom fixture forming a second re-entrant surface. When the fixtures are mounted, the re-entrant surfaces form a testing space in the center to accommodate a specimen to be tested and the re-entrant surfaces provide testing forces in two axes in response to an actuator providing motion of at least one of the fixtures in one axis.

A test piece includes a tensile testing part and load applying pieces that are respectively connected to sides of the tensile testing part. Grooves are formed on bottom surfaces of the load applying pieces. Grooves are formed on upper surfaces of the load applying pieces. These grooves respectively partition the upper and lower surfaces of the tensile testing part and the load applying pieces.

The present invention includes a load frame test device using a plurality of levers about a common pivot point for applying combinations of tensile loading and bending on test articles at magnitudes seen in offshore applications.

Methods for measuring the effective fracture toughness in a material are described. A rail and roller system are used to apply a gradual force to a specimen. The time-dependent force creates a steady fracture development that allows a camera to record the progressive fracture in the material. Mathematical methods can then be used to analyze the fracture progression and determine the effective fracture toughness.