Concrete pipes: Are they manufactured and tested to AS/NZS 4058?

National Precast CEO Sarah Bachmann talks about the significance of AS/NZS 4058 for precast concrete pipes, and how to tell the difference between compliant and non-compliant products.

Australian Standards are in place to ensure that all suppliers are manufacturing and testing their products in accordance to strict guidelines and, in the construction industry, compliance with relevant Standards is paramount. It is vital that all asset owners, both in the private and public realm, have confidence that the products they are buying and installing meet the requirements of the relevant Australian Standard.

National Precast’s Chief Executive Officer, Sarah Bachmann, says when it comes to precast concrete pipes, that Standard is AS/NZS 4058:2007 Precast concrete pipes (pressure and non-pressure), more commonly referred to as AS/NZS 4058.

“One of the key requirements of AS/NZS 4058 is to make sure pipes will deliver a 100-year in-service design life,” she explains.

“The required testing for a concrete pipe is outlined in AS/NZS 4058 Section 4, whereby the verification of Finished Product Compliance includes Proof Load Test and Ultimate Load Test.”

AS/NZS 4058 was prepared and published in 2007 by the joint Standards Australia/Standards New Zealand Committee – WS-006 – to supersede two respective Australian and New Zealand Standards. Those two Standards were AS 4058 – 1992 precast concrete pipes (pressure and non-pressure) and NZS 3107:1978 Specification for precast concrete drainage and pressure pipes.

Ms. Bachmann says a 100-year design life can be expected when pipes are manufactured in accordance with AS/NZS 4058 and installed in a ‘normal’ or ‘marine’ environment. ‘Other’ environments that are more aggressive should be assessed for suitability using appropriate engineering judgement.

She says there are risks associated with pipes that do not meet these requirements – they may be of a lesser quality and could therefore lead to line failures on site. Ms Bachmann says in order to confirm that compliant pipes are being supplied, it is important to check they are visibly marked with the information required by AS/NZS 4058.

As outlined in Section 1.5 Marking of the Standard, the information to be marked includes:

the manufacturer’s name or registered trademark and the location of manufacture
the date on which the pipe was cast
the nominal diameter and load class e.g. DN750/3
where an elliptical reinforcement cage has been incorporated in the pipe, the word ‘TOP’ indicating the correct laying position of the pipe with respect to the direction of the vertical loading and the orientation of the reinforcement
the maximum mass in kilograms of pipe for the particular pipe class
the number of the Australian Standard the pipes are manufactured to, i.e. AS/NZS 4058.

These markings should be clearly and indelibly marked in a visible location on each pipe. Not only is this a requirement, but it also allows the supplier to have traceability of their product from manufacture through in-service.

“If pipes are being used that are not marked with that information, it could be that they are not made and tested in line with the Australian Standard,” Ms. Bachmann says.

“In this case, it is best to ask the pipe supplier for proof of the required testing in line with the standard for the batch of pipes supplied. The test results should be dated to reflect the batch of pipes supplied.”

National Precast warns against using non-compliant precast products, as they may unnecessarily increase the risk of serious safety, health, economic, legal and social events. The installation of pipes that do not comply with AS/NZS 4058 are no exception. Failure to comply can lead to a reduction in life span (reduced durability), resulting in additional works to replace defected pipes. Additionally, pipes that are not load tested in accordance with the Standard may fail under normal operational loads.

Ms. Bachmann says the financial repercussions of replacing non-compliant pipes can be extreme and cost momentously more than it would have to ensure the product was manufactured correctly to begin with.

“To check whether pipes are compliant, it’s important to request a manufacturer’s certificate of compliance, to guarantee compliance with AS/NZS 4058.”