Marini Master Tower: A ground-breaking approach to reclaimed asphalt pavement (RAP) passe real life field tests with flying colours

The new Marini Master Tower, the innovative asphalt plant that took centre stage at latest Bauma and aims to "think further" by offering solutions that respect the environment and provide clients with real return on investment, has passed its most challenging field test: jobsite life.

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The new Marini Master Tower is the result of over 2 years of extensive study and field trials on over 600.000 tons production.

The partnership between Marini, the University of Bologna and the client proved ground-breaking, and also allowed for the optimisation and calibration of several crucial elements of asphalt production: perfect working temperatures, impeccable depression and a state-of-the-art gas recirculation method, allowing the customer to produce over 300,000 tons of asphalt in the past 12 months alone, with an average use of 47% Reclaimed Asphalt Pavement (RAP), while reducing average asphalt production energy consumption to 75.34 kWh/ton.

The initial tests with various different types of rejuvenating additives proved essential to establish the correct dosage and type of rejuvenator to use in relation to the type of RAP material, and to achieve the correct diffusion and mixing of the new bitumen, together with the "reactivated" one.

Once the initial test phase was completed, additional tests were carried out on the finished product at the customer's lab to verify the compliance of the granulometric curve of the formula, the resulting void index and, above all, the technical characteristics and performance of the asphalt, such as stiffness modulus and indirect tensile strength.

The learning outcome proved how, with the help of an accurate preliminary study and the right investments, it is possible to achieve the desired results and also maintain the stiffness modulus within the correct range i.e. higher than 5000 MPa at 20°C and lower than 17.000 MPa.

A similar consideration applies to the indirect tensile strength, in fact, with the correct additives, it is possible to stay between 0,72 MPa and 2 MPa, as indicated in the ‘specifications for road tenders’ guidelines. It goes without saying that, with the help of appropriate laboratory analysis, it is possible to find the right solutions and the perfect mixture to achieve the right performance parameters.

Thanks to these combined efforts, Marini’s innovative technologies now make it possible to use the highest percentages of RAP, respect the granulometric curve and the quantity and the quality of bitumen indicated in the dosing recipe, all while safeguarding the environment, reducing energy consumption and emissions.