Abstract This study aims to investigate the hybrid effects of carbon nanotubes (CNTs) and steel fiber (SF) on dynamic mechanical behavior ultra-high performance concrete (UHPC) under high-speed loading effects. The functionalized CNTs content varied from 0.0% 0.20%, SF volume was added 0.5% 2.0%. UHPC specimens were tested at strain rates ranging about 60 s-1 240 using split Hopkinson pressure ...

The cracking resistance and durability of the ultra-high-performance concrete (UHPC) structure are directly affected by its tensile behaviour. A micro-analysis method was established to study behaviour UHPC before appearance visible cracks. cooperative characteristic steel fibre cement matrix taken as a research focus method. random distribution considered normal distribution. Based on method, ...

Abstract The composite structure composed of ultra‐high performance concrete (UHPC) and normal (NC) has been widely applied to engineering structures. U‐shaped shear studs play an important role in the combination UHPC‐NC interface. To investigate interface characteristics with studs, numerical model 14 various parameters is calculated based on push tests. influences diameter, stud number, NC e...

To improve sustainability and reduce costs, interest in using limestone powder (LP) ultra-high performance concrete (UHPC) has been increasing recent years. Incorporating LP changes packing, characteristics of C–S–H pore structure interfacial transition zone (ITZ) matrix by physical chemical effects. However, the influences replacement on mechanical properties UHPC, from micromechanics to macro...

Ultrahigh-performance concrete (UHPC) is a new class of concrete, differentiated from conventional by clear distinctions in its material behaviors. Understanding and managing time-dependent properties necessary for the appropriate use any concrete-like material. This study investigated suite commercially available UHPC-class materials, with goal being to characterize behaviors then propose pred...

Experiences in the development of Ultra High Performance Concrete found a very high flowability in concrete with low water powder ratio. Because of the high viscosity of the cement paste, compaction was necessary. To improve the compaction characteristics of the concrete the idea of adding coarse aggregate was developed. The first tests showed a good workability of the fresh concrete and a good...

New Canadian and American standards for concrete bridges now provide guidelines the design, production, curing, material characterization, installation of ultra-high performance fiber reinforced concretes (named UHPFRC or UHPC) on structures. However, some technical aspects require more research since fundamental knowledge about UHPC is not as complete normal strength (NSC). Among these aspects...

The use of high chemical admixture dosages in ultra-high-performance concrete (UHPC) mixtures to achieve adequate water demand can slow down early cement hydration and prolong the setting time. In this study, effects nanosilica (Ns) with on rheological properties UHPC was investigated. A factorial design approach employed predict optimise Ns content, water-binder ratio (W/B), sand-binder (s/b) ...

Steel–ultra-high-performance concrete (UHPC) composite beams offer numerous advantages, such as structural self-weight reduction, bending stiffness improvement, and tensile cracking limitation in slabs. However, few studies have focused on the shear performance of short stud connectors steel–UHPC structures. To this end, push-out tests were carried out to evaluate effect slab thickness, diamete...

Abstract The use of ultra-high-performance concrete (UHPC) jackets as a seismic strengthening method for reinforced structures has become increasingly prevalent. Specifically, these are applied to plastic hinge regions the improve overall earthquake resistance. This study evaluates effectiveness UHPC in columns through fragility curves. modeled numerically, accounting material nonlinearity, and...