Jetting resistance of concrete pipes

Jetting resistance of concrete pipes

The report 400.I V2 « Jetting resistance of pipes: state of the art » has provided data on high pressure clean water jetting current practices and existing laboratory tests to evaluate the jetting resistance of pipes. It has shown that several test parameters (flow rate, pressure, nozzle used, …) may differ. That leads to various jet power densities.

The second phase of the study, which is the purpose of this report, consisted of evaluating the effect of different jet power densities on a concrete pipes assembly, while controlling back and forth

For all jet power densities which have been tested (from 105 to 1015 W/mm²), jetting doesn’t have significant effects on the current section of the test assembly. Thus, concrete pipes which have been tested stand a jet power density greater than the one that is recommended by existing laboratory test protocols to evaluate the jetting resistance of pipes. These jet power densities are also compatible with current equipments used for high pressure clean water jetting.

However, the most important jet power density (1015 W/mm²) causes impacts on the pipe invert, in the back and forth transition area. In this area, the nozzle is momentarily stationary while the pressure is adjusted.

This transition phase is close to stationary tests conditions described in laboratory test protocols.

Keywords: concrete pipe, jet power, jetting resistance, nozzle