Maarten Kruijer
Papers # 2016 Berlin
To ensure the structural integrity of long term load bearing thermoplastic (like PVC or HDPE/PP) components, the time-dependent behavior of the raw (thermoplastic) material needs to been assessed and integrated in the design procedure. This paper describes how the time-dependent material behavior can be integrated in the design process. As an example, the design of a PVC sewage inspection chamber is elaborated more in detail.
Over the past decades many non-plastic sewage products have been replaced by thermoplastic equivalents. Thermoplastics are more easy to process to a particular complex shape, easier to handle (lighter in weight) and have a lower carbon footprint. On the contrary, thermoplastics in general show time-dependent behavior which is more complex to deal with compared to for instance concrete. Especially, in load-bearing applications, the plastic component is subjected to external loads during its complete lifetime. This leads to the fact that deformations will continue in time and can ultimately lead to premature failure. It is therefore a key issue to have a clear understanding of the time dependent constitutive behavior of the used thermoplastic. In addition, it has to be incorporated in the design methodology for thermoplastic pipes and sewage products.
Having such a design methodology, premature failure can be avoided and effectiveness /competitiveness of thermoplastics over other raw materials is increased as heavy over dimensioning is no longer needed. It aids to reduce the costly trial–and–error time and direct towards a ‘first–time–right’ design. Especially for injection moulded products the (experimental) trial and error approach is costly, as for each design, mould adjustments may be required.
In this paper the design methodology incorporating the time-dependent behavior is presented and applied in the development and optimization of a PVC inspection chamber. An inspection chamber can be installed up to 6 meters deep, and as such, being subjected to a 6m water column (0.6 bar) during its entire lifetime. As a consequence, continuing deformations of the chamber can lead to failure or unfit for usage after a period of time.
To this end, firstly the base material is tested for its time dependent constitutive behavior by creep experiments. Subsequently, a viscoelastic material model is set-up for the PVC and is implemented in a finite element program. Finally, the mechanical (long-term) requirements for the chamber are outlined and the design procedure is used to engineer the PVC chamber to be optimized for its usage.
Related papers
Author(s) : A. Marangoni
The quality of infrastructures is a key driver for maximizing the performance of the utilities networks and minimizing the environmental impacts associated with their operation. The water and sewer pipes are key network elements to guarantee a satisfactory service to the citizens. Their end-of-life management is an...
Author(s) : Saleem Shakir
Unplasticized formulations based on Poly(Vinyl Chloride) (PVC) and Chlorinated Poly(Vinyl Chloride) (CPVC) resins offer technical solution to pressure piping systems that find extensive use in residential and industrial applications. Building upon the desirable properties of the vinyl monomer, the chlorine content of...
Author(s) : Andreas Moerman, Flip van der Valk, Mirjam Blokker KWR, Tjakko Haaijer, Jan Vreeburg,
Drinking water companies with ageing networks are facing vast amounts of drinking water network reconstructions during the coming decades. This development coincides with the energy transition, which puts pressure on the available space underground. These external drivers give drinking water companies an opportunity...
Author(s) : Joe Babcanec, P.E., Dan Currence, P.E.
The newly released Drainage Handbook provides complete guidance on corrugated polyolefin pipe. Perhaps the biggest contribution this new handbook makes to the advancement of both HDPE and PP corrugated plastic pipe is the design procedure presented. The design procedure reflects the industry’s recommended practice for...
Author(s) : James F. Mason, Akshay Ponda, Hermann van Laak, Buc Slay
The effects of liquid hydrocarbons on long term strength of pipe grade thermoplastic resins is an important consideration when designing pressure pipe for use in the oil and gas industry. There is an extensive body of work going back several decades descri bing these effects for pipe grade polyethylenes, and all...
Author(s) : S. Nestelberger, J. Cheng
The Point Load Test (PLT) [ 1, 2] was designed to simulate the SCG (slow crack growth) failure initiated by a rock pressing into the exterior wall of a polymer pipe. Today’s PE materials sustain long PLT testing times, due to its high SCG resistance design. Consequently, an accelerated “PLT+” with the support of...
Author(s) : Antonio Rodolfo Jr., Vanderley M. John
Unplasticised (U-PVC) and modified (M-PVC) pipes used in irrigation and infrastructure applications, outside diameter 326 mm, were evaluated according to various fracture mechanics methodologies, including fracture toughness (stress intensity factor KC and energy release rate GC, both at fracture), essential work of...
Author(s) : Gerald Pinter, Johannes Wiener, Florian Arbeiter, Abhishek Tiwari, Otmar Kolednik
For pipe applications, catastrophic failure due to crack growth has to be prevented by all means. Techniques to develop new and even tougher pipe materials are explored in this contribution. The aim is to create a multi-layer architecture, that exhibits high toughness as well as damage tolerance towards sharp notches....
Author(s) : C. Losher and P.V. Mercea
In the framework of the German Environmental Agency (UBA) requirements of plastic articles in contact with drinking water (KTW-BWGL-guideline), the compliance is verified by comparing so-called “expected concentrations at tap”, C tap , of substances contained in the plastics with specific limits in drinking water...
Author(s) : Dustin Langston
The design and installation of polyethylene systems can be complex, specifically due to the many applications and environmental conditions that surround those systems. Online design tools have been developed to address this complexity and the various factors that must be considered. These online tools used widely in...
Author(s) : Sylvie Famelart, Vincent. Stone
In order to deliver to the market reliable and consistent information about PVC and the different PVC pipe solutions, a Training Package was developed a few years ago. The package was made up of a set of standalone PowerPoint slides, providing information on PVC-U and PVC-C pipe systems. Information on both general...
Author(s) : Argnani Claudio, Ing. Gianpaolo Contarini
...Clogging of the pipes can be experienced in sewer systems after a short period of service, due to the intrusion of roots from plants and trees. Plants, and in particular their roots, are attracted by the water flowing inside the pipes. These roots will strain the connections between pipes, in particular the sockets...
Author(s) : Ignacio Muñoz
“Food is the new oil and gas” is a rather bold statement, but everyday more and more people are concerned about food scarcity. Bringing irrigation to not productive lands will change the lives of the community and if it can be done with a cost effective and the most ecofriendly solution, even better. This case study...
Author(s) : Guido Quesada
An important breakthrough for belled PVC pipe was made around 2006, when the first versions an integral joint restraint were released, after about two years in development. This type of restraint comprises a casing, usually made of metal such as ductile iron or stainless steel, a rubber seal, and a “C” grip ring,...
Author(s) : Andreas Frank, Mario Messiha, Günter Dreiling, Norbert Schuler, Jens-Martin Storheil, Erwin Mayrbäurl, Stuart Ramella, Frank Krause, Rudi Berning, Philippe Gabriëls, Alpay Aydemir, Thomas Koch, Florian Arbeiter, Gerald Pinter
The Cyclic Cracked Round Bar (CRB) Test has been applied to study the slow crack growth (SCG) resistance of virgin, recycled, and reprocessed PVC-U. This fracture mechanical test allows a quick ranking of the SCG resistance of PVC-U. A clear correlation between the K-value and the SCG resistance has been elaborated....
Author(s) : Amster Howard
Deeper pipe burial, less expensive and environmentally friendly backfill, uniform language for contractors and inspectors, simplified installations for smaller pipe, and allowable construction in poor soil conditions are highlights in the latest edition of AWWA M55 and all benefit the users of HDPE pressure pipe. This...
Author(s) : Dr. Stefan Fokken
NGO pressure and end of life disposal of PVC articles in the EU over 30 years ago, triggered intense discussion about the sustainable use of PVC and its additives. Stabiliser producers and downstream users of PVC stabiliser compounds base upon Lead and Cadmium based stabilisers have developed solutions ultimately...
Author(s) : E. Boccaleri, L. Palin, G. Rombolà, M. Milanesio
In the last decades, research on nanostructured materials as additives for plastics involved several polymeric matrices, but only limited studies and publications involve PVC. In this work, the context of rigid application of PVC (U-PVC) for pipes application was targeted, in order to test and evaluate the structural...
Author(s) : Steven Folkman
A recent survey again confirms that PVC pipe has the lowest break rate when compared with break rates of ductile and cast iron, asbestos cement, steel, and concrete pipe. Other results of interest to water utilities and engineers are discussed. During 2017, Utah State University conducted a survey of utilities across...
Author(s) : Gerald Pinter, Florian Arbeiter, Johannes Wiener, Andreas Frank, Otmar Kolednik
In order to further increase the fracture toughness of pipes, biomimetic layer design of the pipe wall can be used. Therein, soft polymer interlayers can act as crack-arresters in a matrix of stiffer and inherently more brittle polymers. The effectiveness of the crack arresting role of soft interlayers in a...
Members of the Association
