February 20, 2012

Why you need to test concrete on the site

Guest Column | Charles Kelly and Allan Maynard

The inspection and testing of concrete are an integral part of the concrete construction industry and provide accurate assessment of the product's expected performance and safety.

The results from proper testing are also the primary indicator of the quality of an installation and ensure the consumer’s return on investment.

The ultimate test results that confirm that the concrete placed at a construction site meets the specified strength come from the certified concrete testing laboratory.

Even with an initial indication after seven days, it is well understood in the construction industry that these results only become available 28 days after the concrete has been placed at the site and therefore, do not provide any kind of early warning of non-conforming concrete.

It is vital that field testing of the concrete for slump and air content be the main tools of quality control during the critical phase of concrete production and the placement, to ensure that the concrete meets the requirements for workability, durability and strength.

The reality is that concrete is a perishable product.

Despite the rigour of the certification processes and test procedures, jobsite conditions can occasionally interfere with the ability to carry out the tests in strict accordance with the standard.

Also, despite the efforts of ready-mix producers to proportion and produce high quality concrete mixtures, occasionally mixes can be delivered that are out of compliance.

Concrete field testing and the issues associated with acceptance and rejection of concrete on site, have been seen to be intractable.

Disputes around results can be costly to all parties involved in a project – the concrete supplier, the testing company, the consultant and the contractor.

All efforts must be made to eliminate such disputes.

Recognizing that more must be done to alleviate these issues, the Canadian Council of Independent Laboratories (CCIL) and the BC Ready-Mixed Concrete Association (BCRMCA), established a joint and collaborative working group.

This group of representative professionals, from certified laboratories and concrete producers, have been meeting together for more than 10 months, sharing real-life experiences in a totally frank manner with the intent of fostering co-operation among parties to resolve issues quickly and co-operatively.

The goal is to avoid the rancour and finger-pointing that can arise when things don’t go as planned.

Seeking practical solutions, this joint working group has produced a Best Practices Guidelines for Concrete Field Testing and Sample Collection, that will be available for industry-wide distribution in a few weeks.

This document is intended to assist all parties involved in a project requiring the placement of concrete.

The document addresses the roles and responsibilities of the key players in any project.

It outlines how the parties need to communicate before the project begins, during construction and recommendations for action when issues are encountered.

The glaring omission in current industry practices is how rarely the testing organization and the concrete supplier are engaged together with the contractor, in the pre-construction meeting.

The message to all partners in the construction industry is that beginnings are everything.

We wish to congratulate our respective members for the dedicated hard work and commitment they have shown in working through the tasks to prepare this best practices guide.

They have demonstrated, by example, how our industry can work together through shared values of integrity and pragmatism.

Charles Kelly is the president of the BC Ready-Mixed Concrete Association. Allan Maynard is the executive director of the Canadian Council of Independent Laboratories, an association representing independent consulting, testing and inspection companies.

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