Superflat Concrete Excellence: The Making of a Golden Trowel–Winning Project

The Superflat of Ashine Diamond Tools Manufacture Center was designed to achieve a  Superflat standard (FF ≥ 90, FL ≥ 90) — a specification typically required for high-bay racking systems exceeding 13 meters in height. 

Designed by Twintec China Co., Ltd. and constructed by Xi'an Zhipu Construction Technology Co., Ltd., the project followed a rigorously controlled construction methodology. Through rigorous process control and precision-driven construction, the project ultimately achieved an FF value of 106.8 and an FL value of 159.8 — the highest FL performance ever recorded globally. This outstanding result not only surpassed the original specification but also earned the project the prestigious Global Golden Trowel Award 2025, recognizing it as one of the world's most exceptional superflat concrete achievements.

Phase 1: Pre-Construction Preparation — Foundation Reinforcement & Precision Control

Achieving superflat performance begins long before concrete placement. The preparatory phase focused on two core principles: substrate strengthening and elevation accuracy control.

1. Substrate Milling

The base slab was mechanically milled to:

• • • Remove surface laitance and contaminants
    • Enhance bonding performance
    • Create a clean, structurally sound interface

This ensured strong adhesion between the existing substrate and the new concrete layer.

2. Dowel Installation & Formwork Control

Rebar dowels were planted to improve structural integration. Formwork was installed with strict 3-meter bay spacing, providing:

• • • Stable support geometry
    • Controlled placement zones
    • Reduced cumulative flatness deviation

Maintaining dimensional stability at this stage is critical for high-precision slabs.

3. Bonding Agent Application

A bonding interface agent was evenly sprayed across the prepared surface to prevent delamination and ensure monolithic performance between new and old concrete layers.

Every preparatory step was executed with flatness control in mind, laying the groundwork for achieving superflat tolerances.

Phase 2: Concrete Placement — The Core of Superflat Execution

The concrete placement and leveling stage determines whether the slab can truly meet Grade-A superflat requirements.

1. Concrete Specification

• • Concrete Grade: C30 steel fiber reinforced concrete
  • Slump: 120 mm (controlled for optimal workability)
  • Steel Fiber Dosage: 30 kg/m³ (Twintec system)
     

The addition of steel fibers significantly improved:

• • • Tensile strength
    • Crack resistance
    • Structural stability

This reinforcement strategy ensured dimensional control during curing and long-term service.

2. Precision Leveling Process

During placement, a vibration screed beam was used for initial leveling. However, achieving superflat performance required far more than standard screeding.

The team implemented a "three-stage elevation verification mechanism":

• • • During formwork installation
    • During concrete placement
    • After placement and before finishing

Continuous laser-based checks and manual fine adjustments ensured height accuracy at every phase. This multi-layer control system minimized deviation accumulation and preserved slab geometry.

Phase 3: Surface Densification & Finishing

1. After initial leveling

• • Slurry was properly raised (floating stage)

• • A finishing enhancer (DAY1 additive) was sprayed to improve troweling perfor

2. Dry Shake Hardener Application

SIKA alloy metallic aggregate hardener (2–1 grade) was broadcast evenly in two applications at 6 kg/m² total consumption.

  This enhanced:

• • • Surface wear resistance
    • Impact durability
    • Long-term abrasion performance

3. Mechanical Troweling & Edge Refinement

Finishing was completed using:

• • • Dual ride-on power trowel machines
    • Single-disc trowels for detail refinement

Special attention was given to edges and corners—areas commonly responsible for flatness inconsistencies. Manual precision finishing ensured uniformity across the entire slab.

Phase 4: FF/FL Verification — Measured Performance

Upon completion, the slab underwent flatness and levelness testing using a FACE floor profiling system.

Measured Results:

• • • Average FF: 121
    • Average FF: 156

The achieved FF value far exceeded a superflat standards(≥90), confirming:

• • • Exceptional elevation control
    • Minimal wave amplitude
    • Outstanding suitability for high-bay racking systems (≥13 m)

The results validated the effectiveness of the project's precision-driven construction methodology.

Project Significance

This Golden Trowel–winning project demonstrates that world-record FF106.8 FL159.8 performance is not accidental — it is the result of disciplined process control, technical expertise, and uncompromising quality standards.

For high-bay warehouse flooring, VNA logistics systems, and precision manufacturing facilities, this project now serves as a global reference case for what modern superflat concrete engineering can achieve.