Accurate concrete compressive-strength testing starts with a properly prepared specimen. Before a hardened concrete cylinder can be tested, its ends must be flat, smooth, and parallel, so the applied load is distributed evenly across the specimen.
That is where sulfur capping compound comes in.
Traditionally, sulfur capping compounds are made from molten sulfur combined with mineral fillers. When melted and poured onto the ends of concrete cylinders, the material rapidly hardens to create a level, high-strength surface suitable for compressive testing.
For laboratories and testing facilities looking for a capping material that is easy to handle, fast-setting, consistent, and economical, Sauereisen 600 Basolit Sulfur Capping Compound (Nukem) offers several advantages.
Easy-to-Handle Flakes
Not all sulfur capping compounds are supplied in the same form.
Sauereisen 600 is manufactured as ultra-thin flakes, providing a significant handling advantage over traditional sulfur ingots or bricks. The flakes can be easily scooped or poured directly into a heated melting pot, allowing operators to quickly add material as needed throughout the workday.
The flake form also requires less effort to mix, and dose compared with larger sulfur bricks.
Unlike sulfur powder, the flakes are non-dusting, helping create a cleaner and more convenient working environment.
Sauereisen 600 is also sold in 50 lb. bags, making it more economical and easier to store and handle than ingots which are offered in drums and boxes.
High and Consistent Compressive Strength
Consistency is critical when preparing specimens for compressive-strength testing. Variations in the capping material can affect how the load is transferred to the concrete specimen.
Sauereisen 600 is carefully manufactured and plasticized to provide even load distribution during compression testing without deformation.
The material achieves a compressive strength of:
- 8,000 psi minimum at two hours according to ASTM C617
- 9,000 psi according to ASTM C579
This high compressive strength helps provide reliable, repeatable caps from specimen to specimen.
Just as importantly, the consistency of the flakes helps maintain high strength from cap to cap and bag to bag.
Fast Melting and Rapid Setting
Time matters in a busy concrete testing laboratory.
Sauereisen 600 melts quickly at approximately 230°F–240°F (110°C–115°C), allowing operators to prepare the capping compound without unnecessarily long melting cycles. The compound also has a reduced odor compared with many traditional sulfur materials.
Once poured, 600 sets rapidly—typically in approximately one minute.
After cooling for two hours, the material reaches a minimum compressive strength of 8,000 psi in accordance with ASTM C617.
The result is a capping compound that allows testing operations to move efficiently from specimen preparation for strength testing.
A Wide Pouring Range
Maintaining the correct temperature is important when working with molten sulfur capping compounds. Sauereisen 600 provides operators with a relatively broad optimum pouring range of 265°F–290°F (129°C–143°C).
That range provides practical flexibility during day-to-day laboratory operations.
Even if the compound is accidentally overheated, 600 does not have to be discarded. Once it has cooled to the proper temperature, it remains usable.
And if material is poured, solidifies, and remains in the melting pot, it can be remelted without loss of properties.
That reusability can help reduce material waste and operating costs.
Strong Bond to Concrete
A strong cap needs to stay firmly bonded to the concrete specimen throughout testing.
Sauereisen 600 has a bond strength of greater than 150 psi, as measured by ASTM C321.
Its strength and bond properties also remain stable during storage. Capped specimens can be stored at 100% relative humidity prior to testing without degradation of the capping material.
This is particularly important for laboratories dealing with specimens that cannot be tested immediately after capping.
Flakes vs. Sulfur Bricks
Compared with traditional sulfur bricks or larger solid forms, Sauereisen 600 flakes provide several practical advantages.
600 flakes:
- Require less energy and effort to mix
- Are easier to handle
- Are easier to measure and dose into the melting pot
- Can be added incrementally throughout the workday
- Melt quickly and efficiently
- Are easily stored and handled
The result is a capping compound designed around the needs of the laboratory operator.
Flakes vs. Sulfur Powder
Sulfur powder may appear convenient because of its small particle size, but it can create dust during handling.
Sauereisen 600’s ultra-thin flakes provide many of the handling advantages of a finely divided material without the dust associated with sulfur powder.
The flakes can be scooped or poured directly into the melting pot, making material addition simple and controlled.
Sulfur Capping Compound vs. Capping Pads
Sauereisen 600 can also provide an economical alternative to reusable neoprene or other capping pads.
Unlike rigid capping materials, the carefully plasticized 600 compound is designed to provide even load distribution during testing without deformation.
Its properties also make it less likely to interfere with equipment calibration and can help reduce wear and tear associated with more rigid capping systems.
For laboratories performing a high volume of compressive-strength testing, the combination of performance, ease of use, and economical operation makes sulfur capping compound an attractive alternative.
Designed to Meet ASTM C617
Sauereisen 600 is formulated to meet or exceed the requirements of ASTM C617, Standard Practice for Capping Cylindrical Concrete Specimens.
Its combination of high compressive strength, strong bond strength, rapid setting, and consistent performance makes it well suited for concrete testing laboratories, ready-mix operations, construction-material testing facilities, and other applications where reliable specimen preparation is essential.
Sauereisen 600 at a Glance
| Property | Typical Value |
| Bond Strength | >150 psi, ASTM C321 |
| Compressive Strength | 9,000 psi, ASTM C579 |
| Compressive Strength at 2 Hours | 8,000 psi, ASTM C617 |
| Density | 136.5 pcf, ASTM D71 |
| Melting Range | 230°F–240°F (110°C–115°C) |
| Optimum Pouring Range | 265°F–290°F (129°C–143°C) |
| Set Time | Approximately 1 minute |
| Form | Ultra-thin flakes |
| Packaging | 50-lb moisture-resistant bags |
| Standard | Meets or exceeds ASTM C617 |
Consistency You Can Count On
When compressive-strength testing is used to evaluate concrete performance, specimen preparation should not introduce unnecessary variables.
Sauereisen 600 Sulfur Capping Compound is designed to make that preparation simple, fast, consistent, and economical.
Its ultra-thin flake form makes the material easy to handle and dose. Its high compressive and bond strengths provide reliable performance during testing. Its rapid melting and setting characteristics improve laboratory efficiency. And its ability to be remelted after accidental overheating helps minimize waste.
For laboratories that need a dependable sulfur capping compound, Sauereisen 600 delivers the performance and convenience expected from a professionally manufactured testing material.
Sauereisen 600 Sulfur Capping Compound — consistent caps, reliable testing, and easier handling.