Endurazyme #388 is a proprietary bioenzyme stabiliser designed to allow greater use of marginal in-situ pavement materials.
Tararua District Council investigated the use of Endurazyme #388 as a way to reduce the cost of maintaining their unsealed roads.
Four trial sections of road were constructed in 1995 to evaluate the relative effectiveness of adding Endurazyme #388. The sections were monitored from December 1995 to December 1996.
Two of the trial sections were treated with Endurazyme #388, one section was treated in the same way but without adding Endurazyme #388, and one section was a 50 mm-thick, granular wearing course constructed to represent good practice for unsealed roads.
Following periods of heavy rain however, the pavement surface on some of the trial sections became soft and slushy.
Safety concerns resulted in the trials being terminated in late 1996, some 2½ years earlier than planned.
It was not possible to conclude if the addition of Endurazyme #388 had any significant effect on reducing potholes, corrugations or rutting, or reducing pavement wear, except that it did reduce dust for a short period.
The 50 mm granular wearing course trial sections (without Endurazyme) had the lowest long-term dust emissions and the lowest roughness, and was the only section that provided safe passage for the entire duration of the trial.
Keywords: bioenzymes, clay modifier, Endurazyme #388, New Zealand, pavements, roads, stabilisation, Tararua District, treatment, unsealed roads