The disclosure relates to apparatus and methods for uniaxial testing of a solid specimen, such as an asphalt or asphalt concrete specimen. The apparatus provides a simplified and accelerated procedure for mounting and testing asphalt mixture samples and other solid specimens under uniaxial tension and/or compression, in particular to measure corresponding uniaxial strain and/or fatigue in the specimen. The apparatus incorporates two opposing collet-chuck elements to rapidly mount and fixedly hold a solid specimen in place in a loading system to apply uniaxial loads. The disclosure further relates to an off-specimen means for measuring strain in a specimen using optical imaging in which successive time series images of a specimen during uniaxial loading can be analyzed to determine displacements and corresponding strains.

Provided is an in-situ testing apparatus for a material mechanical behavior under neutron and X-ray fusion imaging, belonging to that technical field of material mechanical behavior testing. The in-situ testing apparatus includes a mechanical loading test module, a positioning support module, a variable temperature loading module, an X-ray phase contrast imaging module, and a neutron imaging module. The imaging sensitivity is high by adopting X-ray phase contrast imaging. A moving base can drive spatial positions of modules such as a test cassette and a neutron imaging module. A neutron receiver and a neutron upstream emitter can be matched to the same axis, thus solving the problem that the neutron imaging module and the X-ray imaging are difficult to be integrated into one system.