AVERAGE VALUE OF STRENGTH TO COMPRESSION 75.5 Kg/cm2
The compression strength of Fiorditufo blocks, fbm = 75,5 Kg/cm2, produces a characteristic strength equal to fbk = 0,75 × 75,5 = 56,6 Kg/cm2.
Consequently, depending on the mortar used, the masonry characteristic strength fk and its acceptable base tension σm = fk/5, i.e.fk /4,2 according to the Ministerial Decree (D.M.) on buildings of 14 January 2008, are as in the table:
The verifications of masonry strength to vertical loads can be developed at least for buildings with no more than three floors and walls slenderness not over 12, with the simple formula σ = N/xA 0.50 ≤σm where N is the total vertical load at the base of the lowest floor of the building, and A is the total area of the load-bearing walls at the same level.
The characteristic strength to cutting fvk= fvko + 0,4 σn.
Where fvko equals 1,5 Kg/cm2 **(o 2,0 Kg/cm2)* for masonry made with mortars M15, M10 and M5 and 1,0 Kg/cm2 for masonry made with mortar M2,5 .
And σn is the average normal stress due to vertical loads on the section considered.
* Value in Ministerial Decree (D.M.) of 20 November 1987 on masonry buildings.
** Value in Ministerial Decree (D.M.) of 14 January 2008 on buildings.