Ultra-High Performance Concrete (UHPC) is a powerful construction material
Ultra-High Performance Concrete (UHPC) alias reactive powder concrete (RPC), is a high-strength, ductile material that is formed by integrating portland cement, silica fume, quartz flour, fine silica sand, high-range water reducer, water, and steel or organic fibers.
The compressive strengths of this type of concrete is up to 29,000 pounds per square inch (psi) and flexural strengths up to 7,000 psi.
The materials are generally delivered in a three-component premix: powders (portland cement, silica fume, quartz flour, and fine silica sand) pre-blended in bulk-bags; superplasticizers; and organic fibers. The ductile behavior of this material is an elementary feature, with the strength to deform and support flexural and tensile loads, even after initial cracking. The application of this material for construction is streamlined with the removal of reinforcing steel and the capacity of the material to be virtually self placing or dry cast.
The strong durability characteristics is formed because of the combination of fine powders chosen for their grain size (maximum 600 micrometer) and chemical reactivity. The outcome is a greater compactness and a small, disconnected pore structure.
Higher density results in creating fewer voids inside, minimizing the scopes for water to infiltrate and create problems throughout the freeze-thaw process. The dense packing also increases the strength of UHPC significantly.
To minimize the carbon footprint of the material, a byproduct of the steelmaking industry (ground slag) is utilized to substitute a significant part of the cement and simultaneously allows to improve the packing density.
A major component in UHPC is steel fibers which include strain-hardening properties to the concrete and as a result when it yields the concrete will bear extreme load before it fails in due course.
UHPC provides huge benefits which range from reduced global costs like formwork, labor, maintenance and speed of construction. Various usages are found bridge beams and decks, solid and perforated wall panels/facades, urban furniture, louvers, stairs, large-format floor tiles, pipes and marine structures.
1. Plumb Bob (For buildings less than 20m in height)
2. Optical Plummet (A transparent plastic sheet is used as a target for checking verticality of tall buildings)
Given below the details of material characteristics for UHPC:
Compressive: 120 to 150 MPa (17,000 to 22,000 psi)
Flexural:15 to 25 MPa (2200 to 3600 psi) Modulus of Elasticity: 45 to 50 GPa (6500 to 7300 ksi)
Freeze/thaw (after 300 cycles): 100%
Salt-scaling (loss of residue): < 60 g/m2 (< 0.013 lb/ft3) Abrasion (relative volume loss index): 1.7 Oxygen permeability: <10-20 m2 (< 10-19 ft2) Cl - permeability (total load): < 10 C Carbonation depth: < 0.5 mm (< 0.02 in.)
To get more detail information, go through the following link. precast.org