Development of an Inline Water Mains Inspection Technology

Hector Hernandez Delgadillo (Speaker)

    Activity: Talk or presentationOral presentation

    Description

    In the Netherlands the drinking water network comprises over 120,000 km of
    infrastructure. Nearly 50% of the pipes is made of polyvinyl chloride (PVC) and just
    about 30% is made of cementitious materials. The condition of the majority of these
    assets remains unknown. Maintenance budget destination and decision-making on
    replacement of assets is challenging without information on the condition of the
    network. Inspecting the water network improves the management of assets and leads
    to an efficient replacement plan of the faulty pipes. Therefore, an inspection
    methodology is proposed which enables the detection and the measurement of
    degradation in the water pipes.

    The long term interaction of the pipes with the conveyed drinking water and
    surrounding soil induces a layer of deterioration on both surfaces of cementitious
    pipes. The ultrasonic signature of these layers can be determined with ultrasonic pulseecho
    (PE) technique. Leaching of calcium is the main degradation mechanism of
    cement-based pipes. For this reason, mortar specimens were partially submerged in
    Ammonium Nitrate solution at different exposure times. Four degradation depths were
    induced: 2.45, 3.2, 3.8 and 5.6 [mm]. Results show that by calculating the overall speed
    of sound in the material it is possible to detect degradation as small as 2.45 [mm]. This
    method has enabled higher sensitivity to thin degraded layers which was still a
    limitation from previous research. Furthermore, the reflected amplitude from the
    water-degraded mortar interface can be used for detecting early stage degradation as
    well. Moreover, the generation of images from full scan of the specimens facilitates the
    detection and localization of different degradation levels.
    Period3 Feb 2017
    Event titleMaintenance Research Day 2017
    Event typeConference
    LocationUtrecht, Netherlands