Testing system for mechanical behaviors analysis and cracking resistance of concrete at early age

A uniaxial experimental set-up was developed to evaluate the self-induced stresses, visco-elastic strains and cracking potential of concrete from the time of its placement. The totally restrained condition is achieved by keeping the length change within a threshold of 3μm. The temperature rise of the specimens can be controlled within 1.5°C, by which the deformation because of temperature change due to cement hydration could be prevented. The tensile force required to compensate the shrinkage could be monitored and elastic strain and tensile creep can be calibrated without an obvious interference of temperature deformation. The preliminary results testified the workability of the system.