Abstract: The method and apparatus for mechanically rubblizing or breaking concrete wherein a plurality of weighted hammers are mounted upon spring biased cantilevered arms attached to a pivoted frame. Upon pivoting of the frame in an impact direction, the hammers simultaneously engage the concrete producing a linear rubblizing or breaking impact zone wherein the proximity of adjacent hammers permits adjacent hammers to multiply the rubblizing and breaking forces and vibrations such that the plurality of hammers operating together simultaneously provide improved concrete rubblizing or breaking characteristics.