PRESENTATION – “Improving the performance of concrete by understanding microstructural properties” by James Mackechnie

Presentation

https://youtube.com/watch?v=33UTYE2fHYs%3F

When: Thursday 3rd March 2016 //

This presentation discussed developing a rational framework for performance properties of concrete. A graphical approach is being developed to illustrate these properties and relationships for structural engineers and a preliminary draft was distributed at the presentation.

Below is the video of the recorded presentation which includes the slides and audio. Also below is a link to the MS Powerpoint slides.

The performance of concrete in terms of its workability, strength, dimensional stability and durability is important when designing concrete structures. Internationally there is a move towards performance-based specifications rather than using a prescriptive approach, which is still commonly found in New Zealand. This presentation focuses on ensuring structural engineers have a better understanding of concrete microstructure in order to better predict how these properties can be achieved in concrete structures. Long held beliefs that structural engineers have about concrete technology will be examined in the light of modern research. Some of these include:-

• Is slump a reliable measure of workability of fresh concrete?
• Does specifying minimum cement contents have any real benefit?
• What is the relationship between drying shrinkage and strength?
• What is the point of specifying an upper limit for core temperatures in mass concrete?
• Should we be enforcing NZS3101 curing requirements for precast concrete?
• What durability tests are appropriate for marine concrete structures?

About the presenter

James Mackechnie is the South Island plant engineer for Allied Concrete and is also an adjunct research fellow at the University of Canterbury. He is a chartered professional engineer and has a PhD in civil engineering from the University of Cape Town.