Ultra High-Performance Fiber-Reinforced Concrete (UHPFRC): a review of material properties and design procedures

Abstract

ResumoThis paper does a review of the recent achievements on the knowledge of UHPFRC properties and in the development of design procedures. UHPFRC is defined as a new material, with unique properties (high ductility, low permeability, very high strength capacity in compression, higher toughness) in comparison to conventional concrete. It is important to know both material and mechanical properties to fully take advantage of its outstanding properties for structural applications. However, since this is a new material, the current design codes are not well suited and should be reviewed before being applied to UHPFRC. In the first part, the following material properties are addressed: hydration process; permeability; fibers role; mix design; fiber-matrix bond properties workability; mixing procedure; and curing. In the second part, the mechanical properties of the material are discussed, together with some design recommendations. The aspects herein examined are: size effect; compressive and flexural strength; tensile stress-strain relation; shear and punching shear capacity; creep and shrinkage; fracture energy; steel bars anchorage and adherence. Besides, the tensile mechanical characterization is described using inverse analysis based on bending tests data. In the last part, material behavior at high temperature is discussed, including physical-chemical transformations of the concrete, spalling effect, and transient creep. In the latter case, a new Load Induced Thermal Strain (LITS) semi-empirical model is described and compared with UHPC experimental results.Keywords: Ultra-High Performance Fiber Reinforced Concrete (UHPFRC), material properties, design procedures, mechanical behavior, high temperature.Este artigo faz uma análise dos recentes avanços nas pesquisas das propriedades do CUADRF e dos seus procedimentos normativos. O CUA-DRF pode ser definido como um novo material, com propriedades muito superiores (grande ductilidade, baixíssima permeabilidade, altíssima capacidade resistente à compressão e elevada tenacidade) às do concreto convencional. O conhecimento das propriedades mecânicas e do material do CUADRF é importante para que todo o seu potencial seja plenamente utilizado. Entretanto, como este é um novo material, as recomendações normativas atuais não são plenamente válidas. Na primeira parte, as seguintes propriedades do material são descritas: processo de hidratação; permeabilidade; efeito dos diferentes tipos de fibras; definição do traço; aderência entre as fibras e o concreto; trabalhabilidade; procedimentos de mistura; e cura. Na segunda parte, as propriedades mecânicas e algumas recomendações normativas são discutidas. Neste caso são examinados o efeito escala, a resistência à compressão e à flexão, a relação tensão-deformação à tração, a força de cisalhamento e de punção, a fluência e a retração, a energia de fratura, a ancoragem e aderência das barras de aço. Além disso, são descritos alguns métodos de análise inversa para a caracterização do material à tração por meio de ensaios ...

Review of The Cement-Based Composite Ultra-High-Performance Concrete (UHPC)

“…With the particle packing model of Andreasen and Andersen [93], the allocation of the UHPC grain size can be established. The particles allocation is calculated according to Eq (6), where coarse mixtures are realized when 0.5>q and small particles are realized when q <0.25 [85,93].…”

“…can be divided into (1) deformed fibers, mostly hooked or twisted, (2) straight or smooth fibers, and (3) the length of the fibers short or long. It is worth mentioning that steel fibers have a high resistance in an alkaline environment, shows high strength, and a high elastic modulus [85].…”

“…7, which introduces a minimum particle size (D min ). Enhancing concrete mix designs for NSC and lightweight concrete has been well accepted by this equation as well as UHPC [85,90].…”

Numerical analysis on displacements of steel-fiber-reinforced concrete beams

“…However, in this work, the goal is to contribute on the understanding of the mechanical behaviour of concrete beams reinforced with steel fibers. In this context yet [21], made an analysis of the recent advances in the area of Ultra High-Performance Fiber-Reinforced Concrete (UHPFRC) leading to the conclusion that the current regulations are not valid to be used in the design of structural elements composed of this kind of material. Also Buttignol et al [21], discusses some normative issues related to its properties, such as bending, compression, stress-strain relations, design criteria, etc.…”

Numerical analysis and experimental testing of ultra-high performance fibre reinforced concrete keyed dry and epoxy joints in precast segmental bridge girders

“…pedestrian and motorway bridges combined) constructed worldwide using UHPFRC in one or more components (Binard 2017;Voo et al 2018). In brief, UHPFRC is an ultra-high strength cementitious material that contains a high quantity of cement and silica fume, low quantity of water, incorporates large amounts of fibres and exhibits remarkable characteristics such as high fracture energy, low permeability, limited shrinkage and increased corrosion resistance (Buttignol et al 2017;El-Tawil et al 2018). Although UHPFRC precast segmental bridges (PSBs) have been widely used in many countries (Voo and Foster 2016;Hafezolghorani and Voo 2018;Chen et al 2016), there is relatively scant information available on the shear behaviour and design of such bridges, especially related to the joints between the segments.…”