The Aggregate Soundness Test Apparatus features automatic heating, constant temperature control, programmable cycle counting, and digital control of soaking and holding time, providing accurate, reliable, and fully automated operation for aggregate soundness testing.

Aggregate Soundness Test Apparatus

Model: TD-J7

I. Product Introduction

The Aggregate Soundness Test Apparatus is designed for evaluating the soundness (durability against weathering) of coarse aggregates in accordance with internationally recognized testing standards.

The test method determines the resistance of crushed stone and gravel aggregates to deterioration caused by repeated cycles of immersion in a saturated sodium sulfate solution followed by oven drying. During the test, the crystallization pressure generated by sodium sulfate is used to assess the aggregate's ability to withstand weathering without significant disintegration, cracking, or loss of strength. This method is widely used to evaluate the soundness (also referred to as stability in some standards) of aggregates.

II. Reference or Applicable Standards

JTG E42-2005 – Test Methods of Aggregate for Highway Engineering

ASTM C88 – Standard Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium Sulfate

AASHTO T104 – Soundness of Aggregate by Use of Sodium Sulfate or Magnesium Sulfate

EN 1367-2 – Tests for Thermal and Weathering Properties of Aggregates – Part 2: Magnesium Sulfate Test

III. Technical Specifications

1. Container: Double-layer stainless steel heating and constant temperature control container.

2. Coarse Aggregate Tripod Wire Basket:

Basket outer diameter: 150 mm

Height: 150 mm

Mesh opening: 2.36 mm

Material: Stainless steel

Outer diameter: 100 mm

Height: 150 mm

Mesh opening: 2.36 mm

Material: Stainless steel

3. Fine Aggregate Tripod Wire Basket:

Basket outer diameter: 70 mm

Height: 70 mm

Mesh opening: 0.15 mm

Material: Stainless steel

4.Power Supply: 220 V

5. Temperature Control Range: 0–100°C (adjustable)

6. Number of Lifting Cycles: 25 cycles

7. Heating Power: 2000 W

8. Motor Power: 30 W

IV. Product Features

1. Automatic temperature control system with high-precision digital display, ensuring stable test conditions throughout the entire test process.

2. Double-layer stainless steel heating container provides excellent heat preservation performance, corrosion resistance, and long service life.

3. Equipped with stainless steel wire baskets for coarse and fine aggregates, meeting the requirements of different aggregate size ranges.

4. Automatic lifting and cycling system reduces manual operation errors and improves testing efficiency and repeatability.

5. Compact structure, easy operation, and reliable performance, suitable for quality inspection laboratories, highway engineering laboratories, and construction material testing centers.

6. The apparatus can accurately control temperature, soaking cycles, and test duration, ensuring consistent and reliable aggregate soundness test results.

V. Working Principle

The test sample is repeatedly immersed in a saturated sulfate solution and then dried under controlled conditions. The repeated crystallization and expansion of sulfate salts generate internal pressure within the aggregate particles. By measuring the loss of mass and physical deterioration after specified cycles, the soundness performance of aggregates can be evaluated.

The apparatus automatically controls the heating temperature, lifting cycles, and holding time to ensure stable and standardized testing conditions.