Strength research asbestos-cement pipes - Executive Summary - Burst tests increase understanding of material properties of degraded asbestos-cement pipes

Knowledge about the aging of asbestos cement, and of the impact of this aging on the material’s strength, is crucial to making predictions about the condition of asbestos-cement (AC) pipes. This research involved the mechanical testing of the strength properties of pipes that had aged in the field. The values found for stiffness and failure stress are considerably below the catalogue values that have been used until now. With these more realistic strength properties, more reliable predictions can be made in prioritising the replacement of AC pipes.
Interest: prioritising AC pipe replacement Roughly 25% of the drinking water transport and distribution network in the Netherlands is still made of asbestos-cement (AC). Drinking water utilities aim to replace AC pipes over the next decades. To determine which pipes should be replaced first, knowledge about the degradation of these pipes, and the impact of this degradation on their strength, is crucial.
Approach: 30 pipe segments were tested with georadar, thymolphthalein and mechanical testing Thirty asbestos-cement pipe segments taken out due to replacement works, were used for this research. The degradation was determined using the established techniques: georadar and thymolphthalein. The strength properties (stiffness and failure stress) of the pipes were then mechanically tested in the Microlab of the Faculty of Civil Engineering and Geosciences at Delft University.
Report: This research is described in the report Sterkteonderzoek asbestcementbuizen (BTO- 2019.008).