Influence of fibre characteristics on plastic shrinkage cracking in cement-based materials: A review

Plastic shrinkage cracking in cement-based materials may occur at early age and the formation can negatively impact the long-term durability. A detailed review on existing research related to plastic shrinkage cracking is hereby presented including comparisons of laboratory-scale evaluation methods, crack measuring techniques and the influence of various types of fibres. The use of randomly distributed fibres for controlling plastic shrinkage cracking has shown good results and several fibres of different materials, mechanical properties, geometries, shapes, and volume fractions have been presented in the literature. These fibre characteristics were analysed on data from previous studies by descriptive statistics. From this analysis, many relevant fibre characteristics were discovered to have a positive influence on controlling crack formation. These positive effects were found for fibres with a finer fibre diameter, a higher aspect ratio, an increase in number of fibres per volume unit and specific fibre surface as well as the influence of chemical and mechanical interfacial fibre-to-matrix bonds. Also the increase in fibre volume fraction was found to have a positive effect when added to the mixture at an upper limit. No clear correlation was found between the fibre influence on the degree of surface cracking and the fibre length or the fibre modulus. (C) 2019 Elsevier Ltd. All rights reserved.