Calcium Hydroxide C2 (Expansive Mortar)

The expansive stress along the hole depth is almost constant except for that near the entrance of holes. Generally, the expansive loss from the hole entrance has little effect on the demolition work when the hole depth is enough When a free surface exists, the crack, as shown in 5, is pushed apart mainly by the shear stress, and a secondary crack also arises from the bottom of the hole running toward the free surface. the crack width cannot increase but horizontal cracks are initiated. Therefore, in order to obtain two free surfaces, inclined holes or presplitting is required. The larger the hole diameter is, the greater the expansive stress becomes and the wider the hole spacing becomes.