Caratterizzazione fisica e chimica e diagnostica del processo di deterioramento della formazione calcarea di La Tampa usata nelle architetture di Medellin (Colombia) / Physical and Chemical Characterization of Deterioration Process of La Tampa Formation Limestones used in the architecture of Medellin (Colombia)

The limestone of the La Tampa Formation is widely used as dimension stone in different urban setting, including facades, floors, and general ornament in the urban architecture in Medellín city. Four commercial products are exploited in two stope faces. The stope face 1 produces biosparite limestones, with a good sorting and rounding, cemented by crystalline sparite. The limestone exploited on stope face 2 is biomicrite, with poor sorting and micrite matrix. Deterioration processes such as flaking, black crust, salt efflorescence, fissures, break out and patch development have been observed on these limestones in the Medellín city, caused by the bad quality of the air and the intrinsic stone properties. Different stages of alteration of the rock in the stope-faces, presence of non-carbonated minerals such as quartz and iron oxides, and some characteristics linked to porosity and microfracturing, are the most important factors of deterioration. Capillarity absorption and loss water for evaporation and compressive strength tests show differences among the different stone types.