Multitask additive B2last® for road pavement from BASF

In 2020, BASF launched their brand-new additive for warm mix asphalt, B2Last®, a new liquid modifier in both Europe and in the USA. By chemically modifying the asphalt binder, BASF developed an innovative solution for the paving industry. After nearly four years of field usage and trials in different regions, B2Last has proven to be an efficient and cost-effective way to modify bitumen.
September 1, 2023
Credit: BASF
Credit: BASF

The dosage makes the properties! Indeed, this new additive has several purposes depending on how much is used. At lower dosages, it acts as high-performing anti-stripping agent and workability aid for the hot asphalt mixes. By increasing the dosage amounts into bitumen, additional performance requirements can be reached. For instance, B2Last® can have a similar effect into asphalt mixes like any type of polymers or plastomers, by stiffening bitumen at higher dosages. But through a unique process, it´s possible to lower asphalt mix production and lay down temperatures, without any workability and compaction issues. Therefore, it makes warm mix asphalt production possible by using a single product.

Road section on Munich (Germany) city highway A96 using B2Last as Warm Mix Asphalt Additive (2020)

The new additive works differently than conventional bitumen modifiers. It binds components in the bitumen to form a strong polymer grid resistant to permanent deformation occurring in road pavement. Experiences gathered from various paving trials, including the construction of some test sections continue to confirm this. “We proved that B2Last chemically interlinks the aged and virgin bitumen in an effective manner”, explained Olivier Fleischel, Business Development Manager, B2Last. “At the same time, a high proportion of reclaimed asphalt still allows excellent homogeneity and processability of the mixture”. Up to 50% of Reclaimed Asphalt can be used into new asphalt mixes in combination with B2Last, without affecting the overall performances of the asphalt pavement.

“We started with building up our expertise in bitumen and asphalt back in 2015 and went on to work with universities and other independent researchers, before moving onto field trials,” recalls Olivier Fleischel (pictured).

5 years of proven performance almost over

The first roads with B2Last are now terminating their 5th year of operation (paving trials beginning of 2019 in the US and in Germany) and are all performing well. One of the best representative test tracks in Europe (warm mix asphalt with B2Last) will be fully tested by next summer 2024 and this step will permit a rapid product implementation in Germany and neighboring countries. Moreover, in September 2021, a test section was paved on the main test track of the National Center for Asphalt Technology (NCAT) at Auburn University, (Alabama, USA) with a mixed formulation. The resulting binder achieved the Performance Grading (PG) system performance level of 88-22 (the base unmodified bitumen corresponded to a PG 67-22). The full performance profile of this test section will be evaluated and made available upon completion of the testing cycle in late 2024. 

Content produced in association with BASF

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