Effect of different environments on the self-healing performance of Ultra
High-Performance Concrete – A systematic literature review
Bin Xi a,*, Salam Al-Obaidi a,b, Liberato Ferrara a
a Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci 32, Milano, Italy
b Roads and Transportations Engineering Department, University of Al-Qadisiyah, Diwaniyah 58001, Iraq
A R T I C L E I N F O
Keywords:
UHPC, durability
Mechanical property
Self-healing
Exposure environment
A B S T R A C T
Ultra-High-Performance Concrete (UHPC) has been the subject of tremendous research over the years and is
being used in a higher and higher number of engineering applications, especially in highly demanding structural
service scenarios, thanks to both its superior mechanical performance and likewise significant durability in the
un-cracked state. However, as a cement-based material, also UHPC in service condition almost unavoidably
works in a cracked state, though its signature tensile behavior allows damage to be spread into multiple thinly
opened and tightly spaced cracks instead of localizing it into a single wider crack. Cracking can lead to deterioration
of performance, particularly when UHPC structures are exposed, as above, to harsh environments. The
development of self-healing concrete technologies in recent years, has opened new possibilities to enhance the
durability of UHPC in cracked state, empowering with additional capabilities its inborn autogenous self-healing
capacity, which is due to the synergy between its peculiar mix-design composition (high binder content and low
w/b ratios) and the signature crack pattern as above. It is therefore important to explore the development of selfhealing
properties of UHPC under different scenarios, not only as a mean to regain the impermeability lost upon
cracking but also to retain the (tensile) mechanical performance over time, which also results into the capacity of
slowing down the degradation of the overall structural performance. This paper reviews the existing self-healing
technologies used in UHPC and summarizes the self-healing properties and their effect on mechanical properties
of UHPC when exposed to different environments, also including salt water, geothermal water, wet/dry and
freeze/thaw cycles and low temperatures.