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MAC - Mechanical Assessment of Conduits

Switch to MAC and Never Go Back

3 Ways the MAC System will give you Peace of Mind in the Structural Integrity of your Sewers

The MAC (Mechanical Assessment of Conduits) system is a non-destructive, digital assessment method developed at Eau de Paris, the French capital’s water authority. The MAC’s non-destructive, comprehensive and objective analysis system has tested more than 40km of pipeline every year and is endorsed by Germany’s Institute for Underground Infrastructure (IKT).  

MAC has given peace of mind to pipeline asset managers in cities throughout Europe including: Paris in France; Hamburg and Dusseldorf in Germany and also in Bournemouth and Weston-super-Mare in the UK.

The top 3 reasons why switching to the MAC system will give you peace of mind in the structural integrity of your sewers are:

Elimination of Human Error
Certainty of Rehabilitation Method
Confidence the Problem is Solved

Eliminating Human Error

The MAC system assesses the structural integrity of a sewer by the collection and computerised analysis of digital data. The MAC system consists of two basic elements:

The MAC inspection
Finite Element (FE) Calculations

The MAC system at work – Stage1 the MAC inspection Procedure

The MAC inspection is conducted as follows:

The MAC’s high-pressure cylinder applies sufficient force to cause a reaction in the pipeline material without causing damage. MAC is a non-destructive test method.
Precise sensors measure the resulting deformation of the pipe/soil system
The stiffness can then be calculated by comparing the deformation of the pipe/soil system to the pressure applied.

The MAC system - Stage 2 FE Calculations - sewer (orange) represented within the surrounding soil (yellow), showing application of load by the MAC unit (arrows) 


The MAC System - Stage 2 FE Calculations – figure illustrates displacement in the sewer wall and soil due to the application of load by the MAC unit

From sectional drawings and/or construction documentation, a three-dimensional Finite Element model of the entire pipe/soil system is developed. The results from the Finite Element modelling are:
The moduli of elasticity is represented for the entire length of the pipe/soil system
The entire sewer length is classified into zones of identical pipe and soil stiffness
Potential weak points are located
Reliable input data for calculation of a pipe structural analysis
Locations that require more detailed investigation are systematically specified 

Overall, the MAC inspection and Finite Element calculations mean human error can be eliminated by the comprehensive collection and analysis of data to determine the structural integrity of the pipeline and embedment.

Certainty of Rehabilitation Method

Many infrastructure management authorities must consider these questions:

Repair or completely replace the pipeline? 
Will repair of the pipeline material by re-lining be enough? 
What is the status of the pipe/soil system?
Is the embedment of the pipe still satisfactory?

The MAC inspection and Finite Element (FE) calculations provide comprehensive and objective data to accurately determine the answers to these questions.

The MAC system subdivides the sewer into rehabilitation zones. E.g.:

Water tightness
Improving hydraulics
The retention and/or improvement of the pipe
The retention and/or improvement of the soil and embedment

Dr.-Ing. Mark Klameth, expert in FE calculations at the Institute for Underground Infrastructure in Germany, describes the MAC system as having “undreamed of possibilities” for sewer assessment:

“We can use the supporting FE computations to determine, for example, whether a pipe is cracked longitudinally or transversely, and we can also differentiate between the specific deformation pattern or a weakness in the embedment.”  

The MAC system - IKT online

Have Confidence the Problem is Solved

The MAC system’s collection and storage of data provides objective evidence whether the rehabilitation was effective. Rehabilitated zones can be re-tested and compared with baseline measurements from before the rehabilitation. See the results of rehabilitation objectively documented and have peace of mind that the problem has been solved!

The MAC system also enables periodic re-inspection of the pipeline and measurement of long-term success of rehabilitation methods or focus on critical zones.

Have confidence in the structural integrity of your sewers: Switch to MAC and never go back!

Switch to MAC: Enquire now contacting UVS Trenchless Technology