ASTM D2734 consists of test procedures for determination of void content of reinforced plastics. The void content of a composite may significantly affect some of its mechanical properties. Knowing about void content is desirable for estimation of quality of composites. Higher void contents usually mean lower fatigue resistance, greater susceptibility to water penetration and weathering, and increased variation or scatter in strength properties. ASTM D2734 test methods are applicable to composites for which the effects of ignition on the materials are known. Most plastics, glass, and reinforcements fall into this class. ASTM D2734 test methods are not applicable to composites for which the effects of ignition on the plastics, the reinforcement, and any fillers are unknown.
Some of the composite’s mechanical qualities may be considerably impacted by the number of voids in the material. Higher void contents lead to lower fatigue resistance, greater susceptibility to water infiltration and weathering, and increased variation or scatter in strength qualities. ASTM D2734 test methods specify procedures for determining the void content of reinforced plastic composite materials in testing labs.
What Is the Test Procedure for ASTM D2734?
| Specimen Selection | Sample preparation involves cutting composite material specimens using consistent forms and ensuring statistical validity and accurate material void content representation. |
| Test Setup and Execution | Densities of resin, reinforcement, and composites are measured separately, and a theoretical composite density is calculated. The difference in densities indicates void content. A good composite may have 1% voids or less, while a poorly made composite may have a higher void content. Finite values under 1% represent laminate density quality, but true void content must be established through complementary tests or background experience. |
