It's now possible to measure strain, in a concrete way.

Strain Measurements on Concrete. Concrete is a porous material and generally will have a surface that is too rough to form a very thin and void-free adhesive layer between the strain gage and the concrete.
For these reasons, concrete must first be sealed with an epoxy such as M-Bond AE-10. Long gage length strain gage sensors are typically required on the surface of concrete in order to correctly strain-average over the aggregate and mortar mixture. Since concrete is a poor conductor of heat, precabled gages or gages with preattached leadwires are highly recommended.