UNIBAS M.P.T. triaxial apparatus: from the prototype planning to a consolidated test methodology

The necessity for a univocal characterisation of bituminous binders by mean of the definition of the constitutive link, or, of the failure and yielding functions, have pushed the Authors since 1992 to conceive and realise, inside a research project co-funded by CNR (National Italian Centre for Researches), an apparatus prototype able to realise a pure triaxial type stress state. The original apparatus named UNIBAS M.P.T. (Machine for Triaxial Tests) has been progressively optimised with time from the hardware point of view and from the results interpretation and management. The present memory, twelve years after the realisation of the first prototype, proposes a synthesis of the major scientific results obtained through the use of the UNIBAS M.P.T., underlining also the main applicative relapses in the sector of rational design of pavements and of the verification of mechanical performances of bituminous binders.