Figure 1. Procedure to use expansive cement: A- drill the holes using a hammer drill; B- transfer the expansive demolition agent to a clean bucket;  C- mix homogeneously with the same proportion of water; D- pour the expansive cement in the drill holes previously opened.

Figure 2. (a) Aspect of the sandstone layer A, above the bone-bearing layer B. Main block removed with combined technique stone-splitters and expansive cement, viewed from (b) top before removal, and (c) side after removal (drill holes still visible).

Figure 3. Stone-splitters: A- general aspect of the three parts of the stone-splitter; B- cross-section; C- inserting stone-splitters in the rock; C- putting oil between the wedge and the feathers facilitates the sliding.

Table 1 – Type of rock versus distance between drill holes using different diameter drills (adapted information from CBA® EXPANSIVOS).

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