# Ultra-High-Performance Concrete (UHPC) Piles and Splicing Options
## 3 U HPC Piles  
The Federal Highway Administration (FHWA) [31] defines Ultra-High-Performance Concrete (UHPC) as a \"cementitious composite material composed of an optimized gradation of granular constituents, a water-to-cementitious materials ratio less than 0.25, and a high percentage of discontinuous internal fiber reinforcement.\" UHPC is typically distinguished from other types of concrete based on its mechanical performance. Accordingly, many other definitions of UHPC also include a minimum tensile strength and/or ductility requirement, and many also specify minimum durability criteria [32; 33; 34; 35; 36; 37].  
Because of the superior properties of UHPC materials, PPCPs using UHPC material promise to address the limitations of other piling solutions. The high strength of UHPC (117 MPa to 152 MPa) enables smaller sections and the more efficient use of materials. Piles using UHPC have been used in marine environments due to durability associated with UHPC when compared with piles with other materials. Multiple studies on the durability of UHPC [9; 10; 38; 39; 40] have reached the conclusion that UHPC class material is more durable  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Advantages** & **Disadvantages** & **Applications** & **Ref.** \\ \hline \multirow{3}{*}{Tender Pile} & Pile may copy to health, & Selective in addition and not necessarily. & & \\  & Relatively prepunning, & Pile of industriality only above the ground level. & Small bridge and building construction & [27] \\  & & Relatively prepunning, & Pile of industriality and, & Consistency requirements. & \\  & & Long range of its available, & & Higher and custom attack. & \\  & & Reliability only to police. & Redirectly expensive. & & \\  & & One common theme allows persons, & & & \\  & & Pile lengths from key to regulatory attacks, & & & \\  & & Fine and production and identification, & & Consistency testing helps during. & \\  & & Conse be made of workable materials, & & & \\  & & High- and production and identification, & & Local housing plans & \\  & & Higher sampling, no world ratio, & Limitation from divisibility and installation. & & Fuzzy plans & \\  & & & & Experimental plans & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Summary of the types of driven piles.  
Figure 1: Most common limitation of pile options: (**a**) decayed timber piles of a bridge foundation [18]. (**b**) Corrosion damaged piles in an interchange highway [20]. (**c**) Concrete deterioration of bridge piles and corrosion of reinforcement bar [26].  
than conventional concrete and can be used to extend the service life of concrete structures. UHPC piles have excellent lateral and axial stiffness due to their high elastic modulus of approximately 55,000 MPa, even when reduced sections are used. UHPC piles allow for the application of high prestressing and reduce the spacing between strands [41]. [PERSON] et al. [42] report that UHPC piles can be driven with more ease than conventional piles.  
Current research typically considers developing UHPC pile standards for use as either a direct replacement for or a higher performance option in comparison with currently available conventional concrete and steel H-pile standards. UHPC piles developed as direct replacements aim to have similar or improved moment capacity, weight, and driveability compared with currently used steel H-pile or conventional precast-prestressed concrete pile options.  
UHPC piles come in different shapes and configurations. The common shapes are square, cylinder, H-shaped, modified H-shaped, and octagonal. Various institutions in the concrete industry are standardizing their manufacturing specifications and designs at present.