ASTM D4543-19 PDF Download

ASTM D4543-19 standard provides procedures for preparing rock test specimens and ensuring that they meet the required dimensional and shape tolerances for accurate testing. The standard emphasizes the importance of maintaining dimensional and surface tolerances, especially for strong rocks and specimens that will be tested without a spherical seat. It specifies that dimensional and surface tolerance checks are necessary for the test methods listed in Section 2.1.

The standard also addresses the impact of moisture content on rock properties, stating that laboratory tests should be conducted on specimens that are representative of field conditions. It acknowledges that the moisture condition of the specimen may not match the in situ conditions due to factors like sample collection and specimen preparation, and recommends documenting the steps taken to preserve the moisture content. Excess moisture is highlighted as a potential issue, affecting the performance of resistance strain gages and adhesives used for bonding the rock.

Furthermore, the standard recognizes that it may not always be possible to obtain rock core specimens that meet the desired tolerances, especially for weaker or more porous rock types. In such cases, the standard advises making the best effort to prepare the specimen according to the tolerances specified and reporting it as such. It also includes guidelines on curatorial issues, length-to-diameter ratio, straightness of the cylindrical surface, flatness of end bearing surfaces, and perpendicularity of the end surfaces.