U SHAPE BOX APPARATUS AZA1113

Blocking Resistance Test for Self-Compacting Concrete (SCC)

The AZA1113 U Shape Box Apparatus is a precision-engineered instrument designed to evaluate the blocking resistance of Self-Compacting Concrete (SCC) as it flows through congested reinforcement. This apparatus is widely used in quality control laboratories, construction sites, precast manufacturing units, and research facilities.

Built as per EN 12350-11 and EFNARC guidelines, the U Shape Box test simulates real reinforcement obstacles to help engineers assess SCC’s passing ability, segregation resistance, and suitability for high-density rebar placements.

Key Features

  • Measures SCC blocking resistance through simulated rebar congestion
  • Accurately indicates flowability and passing ability of SCC mixes
  • Robust U-shaped two-chamber design with sliding gate
  • Conforms to international SCC testing standards
  • Includes precision steel rod arrangement and measuring scale
  • Durable, corrosion-resistant construction for field and lab use
  • Ideal for SCC mix design, approval, and continuous quality control
Category:
Description

Description

How the Test Works

  1. Fresh SCC is poured into one chamber of the U-shaped apparatus.
  2. The sliding gate is lifted, allowing SCC to flow horizontally through vertical steel rods.
  3. After the flow stops, concrete heights in both chambers (H1 and H2) are measured.
  4. Height difference (H1 – H2) indicates blocking resistance.
    • ≤ 30 mm: Good passing ability
    • > 30 mm: Indicates blockage or segregation tendency

Applications

  • Evaluation of SCC mix suitability for congested reinforcement zones
  • Precast concrete manufacturing (beams, columns, walls)
  • On-site SCC quality assurance
  • R&D and materials testing laboratories
  • Complementary testing with L Box, V Funnel, and J Ring tests

Specifications

Specification Details
Model AZA1113
Product Type U Shape Box Apparatus
Material Powder-coated mild steel / Stainless steel
Dimensions Height: 600 mm; Width: 410 mm
Rebar Arrangement 13 mm rods @ 35 mm center-to-center
Chambers Dual compartments with sliding gate
Measurement Scale Included on both chambers
Standards Complied EN 12350-11, EFNARC
Application SCC passing ability and blocking resistance test
Accessories Included U Box unit, gate mechanism, scale, instruction manual

Frequently Asked Questions (FAQ)

Q1: What does the U Shape Box test evaluate?
It measures the blocking resistance of SCC as it flows through simulated reinforcement.

Q2: What indicates good passing ability?
A height difference of ≤ 30 mm between the two chambers.

Q3: Why does blocking occur?
Due to poor mix design, high coarse aggregate content, inadequate paste volume, or segregation.

Q4: Can traditional concrete be tested?
No. This apparatus is specifically designed for Self-Compacting Concrete.

Q5: Where is the test commonly used?
QC labs, construction sites, precast plants, and material development centers

Additional information

Additional information

Model

AZA 1113

Product Type

U Shape Box Apparatus

Material

Powder-coated mild steel or stainless steel

Dimensions

Height: 600 mm; Width: 410 mm

Application

SCC flowability and blocking resistance

Accessories Included

Complete U Box, sliding gate, scale, manual