The "Top-Tier Supercar" of the Concrete World — Ultra-High Performance Concrete (UHPC)

Research on the Performance and Application of Ultra-High Performance Concrete

In the field of infrastructure engineering, concrete is the most widely used basic material. However, traditional ordinary concrete has shortcomings such as limited strength, high porosity, susceptibility to cracking, and poor durability, making it difficult to meet the construction needs of super high-rise buildings, long-span bridges, irregularly shaped buildings, and century-lasting projects. Ultra-High Performance Concrete (UHPC), as a new generation of cement-based composite building material, has completely broken through the performance limits of traditional concrete. With its ultra-high strength, ultra-low porosity, ultra-strong durability, and high toughness/crack resistance, it is known in the industry as the "performance ceiling" of concrete.

01 · High densityContains no volatile solvents; does not shrink when hardened.

02 · Strong alkali resistance & corrosion resistanceUsed to manufacture integral containers for low-level radioactive nuclear waste storage.

03 · High strength & good impact resistanceUsed in military and security fields; explosion-resistant and impact-resistant.

01 · UHPC Material Composition and Preparation Principles

Material Composition

Composed of four categories of raw materials — cementitious materials, fine aggregates, toughening fibers, and high-efficiency admixtures — with no coarse gravel aggregate used at all:

Cementitious materials: mainly high-grade cement, blended with ultra-fine active powders such as silica fume, slag, and fly ash.
Aggregate: high-purity, multi-graded fine quartz sand.
Fibers: copper-coated steel fibers at 2%–3% volume fraction, with a small amount of PP fiber to prevent high-temperature spalling.
Admixtures: polycarboxylate high-efficiency water reducer, with a standard water addition of 8%–10% of the total dry powder weight.

Preparation Principles

Mainly based on the theory of closest particle packing, with three core underlying logics:

Multi-level powder filling: silica fume, mineral powder, and fine sand fill voids at successive levels, greatly reducing porosity.
Low water-binder ratio for pore control: extremely low water content reduces harmful interconnected pores formed by water evaporation.
Fiber crack-bridging and toughening: steel fibers are randomly distributed in three dimensions, bridging micro-cracks and addressing the brittleness of the ultra-high-strength matrix; supplemented by steam/standard curing to promote secondary hydration of mineral admixtures, further densifying the microstructure.

02 · UHPC Core Performance and Indicators

Compressive strength: ≥100 MPa; conventional mass-produced products can reach 150 MPa, with modified formulations achieving a maximum breakthrough of 250 MPa.
Tensile strength: ≥3.5 MPa, more than 3 times that of ordinary C60 high-strength concrete.
Permeability coefficient: ≤2.0×10⁻¹³ m²/s, almost completely impermeable; resistance to chloride ion penetration, sulfate corrosion, and carbonation far exceeds that of ordinary concrete.

UHPC Compressive / Flexural Strength Grades
Grade	Compressive Strength (MPa)		Flexural Strength (MPa)		Elastic Modulus (GPa)ᵃ
Grade	Steel / Mixed Fiber	Non-metallic Fiber	Steel / Mixed Fiber	Non-metallic Fiber	Elastic Modulus (GPa)ᵃ
UC100	–	100	–	≥12	≥40
UC120	120	120	≥17	≥15	≥40
UC140	140	140	≥20	≥18	≥40
UC160	160	160	≥24	≥20	≥45
UC180	180	–	≥27	–	≥45
UC200	200	–	≥30	–	≥45

ᵃ For any given compressive strength grade of UHPC, the corresponding flexural strength and elastic modulus requirements must also be satisfied simultaneously.

UHPC Tensile Strength Grades
Grade	Elastic Tensile Strength Standard Value f_te,k (MPa)	Tensile Strength f_tu,k (MPa)	Tensile Strain at f_tu,k ε_tu,k (%)
UT5	5	≥3.5	0.15
UT7L	7	≥7.0	0.15
UT7H	7	≥7.7	0.15
UT9L	9	≥9.0	0.15
UT9H	9	≥10.8	0.2
UT11H	11	≥13.2	0.2

03 · Mainstream UHPC Application Fields

1. Bridge Engineering

Dedicated C120/C135/C150 grades for bridge deck paving on large-span bridges, bridge wet joints, pier reinforcement, repair of defects in old bridges, and lightweight UHPC pedestrian bridges. Solves industry pain points such as traditional deck water seepage and peeling, joint cracking, and repeated repairs. Key domestic projects such as the Yuanjiahe Bridge have applied it at scale.

2. High-end Architectural Decoration

UHPC irregular curtain walls, fair-faced concrete cladding panels, art sculptures, landscape components, and hollow-carved building materials. Combines ultra-high strength with plasticity, enabling ultra-thin, ultra-light, and complex irregular shapes, replacing stone and ordinary curtain wall panels.

3. Municipal and Transportation Engineering

Ballastless track for high-speed rail, railway sleepers, high-speed anti-collision guardrails, tunnel linings, and underground utility tunnel structures, suitable for specialized municipal engineering with high-frequency loads and high durability requirements.

4. Structural Reinforcement and Renovation

High-strength thin-layer reinforcement and repair of old buildings, factories, and roads/bridges — thin, lightweight, and high-strength, without damaging the original structure; reinforcement effect far exceeds that of ordinary repair mortar.

5. Frontier Emerging Fields

3D-printed architectural components, lightweight prefabricated assembled building materials, marine anti-corrosion engineering, and military special protective structures.

04 · Core Advantages of UHPC

Feature 1 — High compressive strength

UHPC compressive strength is 150–200 MPa, far higher than conventional concrete. Under the same load-bearing capacity, component thickness can be halved, significantly reducing self-weight, suitable for large-span and lightweight structures.

Feature 2 — Excellent flexural-tensile toughness

Internal steel fibers form a three-dimensional network, with tensile strength ≥7 MPa. Only minor cracks form under loading, with no sudden brittle fracture; outstanding fatigue and impact resistance.

Feature 3 — Good durability

Resistant to freeze-thaw, chloride ion penetration, carbonation, and acid/alkali corrosion; performs stably long-term in cold, coastal, and saline-alkali environments.

Feature 4 — High degree of forming freedom

The self-leveling mix can be cast into ultra-thin, curved, and hollow-carved irregular components, enabling complex artistic architectural shapes while balancing aesthetics and structural safety.

Feature 5 — Compatible with various construction equipment

Supports factory prefabrication, on-site pumping, thin-layer repair, 3D printing, and other processes; can meet standards with room-temperature curing, compatible with all types of construction equipment.

Feature 6 — Low overall cost across the full life cycle

Initial raw material costs are relatively high, but component cross-sections are smaller with less reinforcement; century-level durability greatly reduces later repair and replacement costs, resulting in lower long-term overall cost.

Ordinary Concrete Beam UHPC Beam

Cumulative Carbon Emissions Comparison Over Service Life (kg CO₂)

Feature 7 — Low-carbon and environmentally friendly

Incorporates large amounts of industrial solid waste such as silica fume, slag, and fly ash, reducing cement usage; low material consumption and long service life reduce construction waste and carbon emissions.