In this feat, Yujiro fragmentates a good amount of the ground of an arena by punching the ground.
This image shows that Kaku Kaioh measures 0.35m from shoulder to shoulder.
Now for the feat itself.
He fragmentated an area of Pi * 3.5^2, that is, 38.4 squared meters. For the depth i'll assume 1 meter, so, using spherical cap for the volume, we get 9948376.74 cc
Fragmentation of concrete is 6j/cc. 9948376.7 * 6 = 59690260.2J
0.014 tons, 9-A
Using violent fragmentation, we get 9948376.7 * 20 = 198967534J, 0.047 tons, 9-A
Ugarik's suggested end:
" Concrete compressive strength for general construction varies from 15 MPa (2200 psi) to 30 MPa (4400 psi) and higher in commercial and industrial structures. "
For an arithmetic medium of 22.5 j/cc
22.5 * 9948376.7 = 223838475.75J or 0.053 tons, 9-A