Customer: SA Water
Location: Adelaide, SA
Delivered: April 2016
The condition assessment report received by the Authority only relied on visual inspection from the surface, without prior cleaning. Interflow considered that more detailed investigation was needed to determine the optimum solution to renew the access chambers.
The Authority asked Interflow to review both the report and the recommendations. Interflow already held a Contract with the Authority and so rates for the various access chamber renewal options were known.
After evaluation, a coating of Interchem® Calcium Aluminate Cement (CAC) was considered sufficient for most access chambers, while Interchem® R epoxy mortar was recommended where the rate of attack indicated very aggressive conditions.
Interflow’s experience has shown that visual inspection is not sufficient to properly determine the condition of an access chamber. Examples that appear similar may be in very different states of deterioration. Interflow proposed cleaning of
each access chamber prior to inspection then chipping at the concrete for initial condition evaluation, and if necessary, taking core samples.
Core samples were used to determine the depth of concrete lost, the depth of acid attacked concrete still attached and the remaining wall thickness. This information was used to calculate the rate of corrosion attack (mm per year), from which a suitable rehabilitation solution was determined.
Interflow was able to show that the rehabilitation required by most of these access chambers was less than recommended in the original report. While some had severe deterioration, core sampling showed that in many others adequate, good
quality concrete remained.
Following a review of the report, Interflow had their Contract extended to include the renewal of these access chambers.
Proper condition assessment by Interflow provided the Authority with confidence that tailored rehabilitation could be carried out, in most cases at reduced overall project cost.
Interflow is committed to offering its customers optimum solutions of the highest value for pipeline and access chamber rehabilitation.