Study: Asphalt Made with Olive Pomace More Resilient to Weathering

Adding olive pomace to asphalt binder made the resulting paving material more resistant to cracking and is an environmentally friendly way to recycle the waste product.

By Paolo DeAndreis
Aug. 13, 2021 12:45 UTC

The right amount of olive pomace incor­po­rated into asphalt binder could dra­mat­i­cally enhance the resilience of paving mate­ri­als to crack­ing and other forms of weath­er­ing, a new study found.

The research con­firmed the results of pre­vi­ous stud­ies and explored the pro­duc­tion process of a new kind of par­tially sus­tain­able asphalt.

The pomace-mod­i­fied asphalt mix exhib­ited bet­ter crack­ing resis­tance after long-term aging than the con­trol mix.- Researchers, OOCC

The study, led by Kun Zhang at the California State University, found that olive pomace could improve the asphalt binder’s resis­tance to events such as oxi­da­tion-induced crack­ing, fatigue crack­ing and crack­ing due to low-tem­per­a­ture events.

In addi­tion, the mod­i­fied binder also com­pared favor­ably to the tra­di­tional asphalt binder when it comes to rut­ting resis­tance.

Olive pomace is the main byprod­uct of olive oil pro­duc­tion and con­tains cel­lu­lose, hemi­cel­lu­loses, lignin, uronic acids, phe­no­lic com­pounds and oily residues.

The mas­sive amount of olive pomace pro­duced by olive oil pro­cess­ing con­sti­tutes an envi­ron­men­tal chal­lenge due to its poten­tial to pol­lute and the costs asso­ci­ated with its dis­posal.

The research, which was funded by the Olive Oil Commission of California (OOCC), showed that olive pomace pulp-rich frac­tion could be pre­cisely sep­a­rated from the stone-rich frac­tion to obtain its opti­mal level of antiox­i­dant qual­i­ties.

By apply­ing this dried olive pomace to the asphalt binder, sci­en­tists found that it mod­i­fied the mate­r­ial with bet­ter soft­en­ing and antiox­i­dant effec­tive­ness, vastly improv­ing its final per­for­mance. They also reported that adding up to five per­cent of the pulp-rich frac­tion would neu­tral­ize the oxi­da­tion caused by asphalt mix­ing and pro­duc­tion.

The use of a higher dosage of pulp-rich frac­tion – e.g., 15 per­cent and 25 per­cent – could sig­nif­i­cantly extend the ser­vice life of mod­i­fied asphalt binders prior to expe­ri­enc­ing ini­tial and severe oxi­da­tion-induced crack­ing,” the researchers wrote. The pomace-mod­i­fied asphalt mix exhib­ited bet­ter crack­ing resis­tance after long-term aging than the con­trol mix.”

See Also:Healthy Compounds in Pomace Oil Absorbed by Fried Foods, Study Finds

The new research con­tributed to the OOCC’s ongo­ing inves­ti­ga­tions on ways to cur­tail the poten­tially pol­lut­ing effect of waste gen­er­ated by olive oil pro­cess­ing on soil and ground­wa­ter.

In a press release, the OOCC empha­sized that future work on this project will focus on the chem­i­cal com­po­si­tion in the processed olive pomace and iden­tify active ingre­di­ents that could fur­ther extend the life of asphalt pave­ments.”

According to the study’s authors, the use of the new asphalt binders would pro­mote sus­tain­abil­ity in both agri­cul­ture and asphalt paving indus­tries.

They also stressed the need to inves­ti­gate active ingre­di­ents in olive pomace to max­i­mize antiox­i­dant capac­ity and develop zero-waste recy­cling meth­ods to uti­lize waste­water in olive pomace.”

Study authors are now seek­ing funds for addi­tional research through the 2021 Agriculture and Food Research Initiative,” the OOCC added, con­clud­ing that it has already sub­mit­ted a let­ter of sup­port for this project, to encour­age valu­able and prac­ti­cal uses for byprod­ucts from olive oil pro­cess­ing.”


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