ASTM C307 Test Standard: Tensile Strength Testing of Chemical-Resistant Mortar and Grout

ASTM is an international standards organization located in the United States of America. It was introduced to the industry to publish technical standard agreements for various materials, products, systems, and more. One of the commonly used ASTM standards in the industry is ASTM C307.

ASTM C307 Test Standard

Description

ASTM C307 is an international test standard designed to determine the tensile strength of specially-shaped briquets of mortar, grout, and other monolithic surfacing materials. Manufacturing industries such as the cement industry frequently use this standard. The materials commonly tested under this standard include mortars, brick and tile grouts, machinery grouts, and monolithic surfacings. These materials typically use resin, silicate, silica, or sulfur binders.

Today, ASTM standards are widely preferred by both corporate and government bodies. In Malaysia, many industries adopt the ASTM C307 standard in their operations, with government recognition of its importance.

Essentially, ASTM C307 measures the tensile strength of a material under tensile strain. Tensile strength tests can be performed using a Universal Testing Machine (UTM), also known as a tensile testing machine. The following tensile properties are typically measured through ASTM C307:

• Tensile stress
• Tensile strength
• Yield point

Specimens

1. Molded Briquet Specimen
   • This specimen is produced from materials such as mortar, grout, and similar monolithic surfacing materials.

Jigs

1. Tensile Grip
   • The grip used in this test consists of two equal parts: top and bottom. These parts ensure uniform traction resistance of the specially-formed briquet specimen.

Extensometers

This test does not require an extensometer because the goal is not to measure displacement or elongation but to determine the tensile strength of the material.

Type of UTM Machine

We recommend using UTM machines with a capacity of 50kN-100kN, depending on the material’s strength. A dual-column floor-type machine is preferable.

1. VEW 2302 Series

VEW 2302 Computer Servo Type Universal Testing Machine integrates electronic technology with mechanical transmission. It offers accurate load speed control, a wide range of force measurements, high accuracy, and sensitivity for load and displacement measurement. This machine supports:

• Constant-velocity loading
• Constant-velocity displacement testing

Main Functions:

• Testing metallic and non-metallic materials in tension, compression, bending, shear, peel, tear, and two-point extensions.
• Suitable for materials such as rubber, plastic, wire and cable, optical fiber and cable, seat belts, leather belts, composite materials, plastic profiles, waterproof membranes, steel, copper, spring steel, bearing steel, stainless steel, castings, plates, strips, and non-ferrous metal wires.

Test Procedure

1. Prepare the specimens according to the method.
2. Typically, the conditioning period for a specimen before testing is 7 days (sulfur-based materials may be tested after 24 hours).
3. Place the specimen into the grips of the UTM machine.
4. Mount and center the specimen in the tension clips.
5. Zero all the testing machine settings before starting the test.
6. Start the test by clicking the Start button on the software.
7. Pull the specimen at 5 to 6.4 mm/min (0.2 to 0.25 in/min) crosshead movement speed.
8. End the test after the specimen breaks (ruptures).