Intelligent design and manufacturing of ultra-high performance concrete (UHPC) – A review

The quick rise of intelligent technologies promotes the development of the construction industry into a new phase. As an advanced cement-based materials, ultra-high performance concrete (UHPC) breaks the performance upper limit of traditional concrete materials, which has also been empowered by intelligent techniques. Hence, this work comprehensively reviews the progress on the intelligent design and manufacturing of UHPC materials. The review mainly includes various design methods and performance characteristics of 3D printed UHPC (3DP-UHPC). The results reveal that currently, the particle packing methods, especially compressible packing model (CPM) and modified Andreasen and Andersen (MAA) model, are domain in designing UHPC materials. Meanwhile, the intelligent design methods, referring to optimal design by computer technology, are also increasingly used due to their high efficiency and accuracy in property predicting. Notably, recently, a new design concept was proposed by the joint use of particle packing models and machine learning techniques. On the other hand, the intelligent manufacturing of UHPC mainly refers to3DP-UHPC. Here, the rheology (especially thixotropy) and printability (pumpability, extrudability and buildability) are crucial for the manufacturing of 3DP-UHPC. Adding steel fibers can enhance the matrix strength, but also will increase the anisotropy of 3DP-UHPC by regulating fiber orientation. Overall, the intelligent development of UHPC is a significant direction for the construction industry, attracting increasing interest and attention. The outcomes of this study emphasize the advantages and significance of using intelligent techniques to design and manufacture UHPC materials, which holds great references and support for future construction projects.