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## Materials Archive |

When opening the program or a new calculation, the starting fixed archive is displayed in which it is possible to add new types of conglomerate and steel or modify the values present. When the calculated section data is saved, the entire modified archive is also stored with it.The nomenclature used to define the strength of concrete is modified by the program depending on whether the operator chooses the S.I. (international) or M.K.S. (technical) system from the Preferences menu or from the initial settings in the Wizard.

Environment for material management

Concrete

Concrete class: Naming of the strength class of the conglomerate by means of an alphanumeric definition of no more than 10 characters. The new NTC (Chapter 4) require the use of standardized designations such as: C20/25; C25/30; C28/35; C35/45 etc. defined according to the characteristic resistance respectively cylindrical fck and on cubes fck,cubes (=Rck).

fck, cubes: Characteristic compressive strength on conglomerate cubes.

Ec: Elastic modulus.

fck: Compressive characteristic cylindrical resistance, fck = 0,83 Rck [point 11.2.10.1 NTC].

fcd: Ultimate compressive calculation resistance, fcd = αcc fck / 1,5 [point 4.1.2.1.1.1 NTC] where αcc =0,85 = coeff. reductive of long-lasting resistances and 1.5 is the coeff. partial safety of concrete.

fctd: Tensile calculation resistance, fctd = 0,7 fctm / 1,5.

fctm:Average tensile strength, fctm = 3 (fck/10)2/3 by classes ≤ C50/60 [11.2.10.2 NTC], fctm = 21,2 ln[1+ (fcm/100)] by classes > C50/60.

Poisson: Transverse coefficient of contraction (Poisson) varying between 0 and 0,2.

AlfaT: Coefficient of thermal expansion [1/°C].

P.S.: Specific gravity of reinforced concrete.

Steel type

Steel Type: Name of the steel grade by means of a free alphanumeric definition of no more than 10 characters.

Es: Instantaneous elastic modulus.

fyk: Nominal yield strength characteristic stress.

fyd: Calculation yield stress = fyk / 1.15 [1.15 = partial safety coefficient].

ftk: Nominal characteristic breaking voltage.

ftd: Calculation breaking voltage. It is the voltage reduced by the coeff. 1.15. at the computational break-down unit deformation equal to 90% of the characteristic break deformation.

ep_tk: Unit deformation εuk at break in the idealized steel diagram equal to 0.01.

epd_ult: ultimate computational deformation equal to εud = 0.9 εuk.

β1,*β2 (start..): coeff. adhesion steel concrete at the first application of the load. It is used by the program in checking the opening of cracks in rare combinations of exercise (SLE).

β1,*β2 (final): coeff. adhesion steel concrete for long-lasting loads. It is used by the program in the verification of crack opening in frequent and quasi-permanent combinations of exercise (SLE).

Operating limit state parameters (Apert. fess. - Normal voltages)

Apert. fess.: this column shows the limit values of the crack opening set out in clause 4.1.2.2.4.5 of the NTC depending on the limit state and the environmental conditions set (the latter must be indicated in the General Data window).

S.cls [aliq. fck]: limit stress of the concrete in operation expressed as an aliquot of the characteristic tension of concrete rupture.

S.fe [aliq. fyk]: limiting voltage of the steel in operation expressed as an aliquot of the characteristic tension of rupture of the steel.By default the parameters are set equal to those provided by the NTC.

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