Materials characterisation and concrete durability

Abstract

In recent decades, microstructural materials characterisation techniques have been employed in the assessment of various types of newly-developed concretes such as geopolymer concrete, recycled and by-product concretes and fibre and nanofibre concretes. Characterisation techniques have also been used to understand durability issues resulting from exposure of concrete structures to harsh and corrosive environments such as maritime infrastructures and concrete members in acid sulphate soils. These corrosive environments can deteriorate and degrade concrete components and lead to the loss of integrity and diminished structural performance and serviceability. The use of microstructural analysis in assessing concrete performance, such as resistance to fire and flexural strength, can be of assistance to improve these properties of concrete. Some of these characterisation methods include scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray mapping (XRM), X-ray diffraction (XRD), simultaneous thermal analysis (STA), thermal mechanical analysis (TMA) and Fourier-transform infrared spectroscopy (FTIR). Although the mentioned methods are well-established techniques, there is a gap in the transfer of knowledge between the experts who can appropriately use these techniques and the structural/materials engineers who need to apply the results. Despite all the benefits these techniques possess, the complexity of the results given seems be an obstacle for engineers who need to interpret them and use them in practice. This paper discusses microstructural materials characterisation techniques with simple examples of their application in engineering practices for concrete structures, focusing on the background knowledge and proper sample preparation needed