ASTM International articles

Providing Statistical Confidence to Pass

Q. Lots are released based on comparing test results from a sample to lot acceptance procedure criteria. If a set of test results meets the lot acceptance procedure criterion, how can I be assured that another sample from the lot would also pass the criterion?

A: Companies use lot acceptance procedures to release a lot. Test results from a sample are evaluated against lot acceptance procedure criteria,

A standard method of determining the splitting tensile strength of rock is proposed. It covers the specifications of the testing apparatus, specimen preparation, procedures, data reduction, and the report format.

A modified Bromhead ring shear apparatus is described, which incorporates vanes on the loading surfaces to improve torque transfer to the specimen. The specimen thickness is increased to accommodate the vanes. A method of specimen preparation is described that ensures a flat shear surface in the center of the specimen. Results are given for the residual failure envelope of Lias clay using the modified apparatus.

Static torsional simple shear tests were performed on poorly graded sand, with and without prior cyclic loading, to evaluate changes in static shear strength. Specimens were prepared at three densities (loose, medium, and dense) and were subjected to one of three levels of cyclic loading corresponding to 0.25, 0.50, or 0.75 times the static stress level, causing failure with no prior cyclic loading. The test results indicate that post-cyclic shear strength increases in specimens that are contrac

The change in void ratio with change in water content of expansive clayey soils due to soil desiccation and water absorption has been identified as the integral/combined curve referred to as S-curve, which describes both swelling and shrinkage paths in the form of the void ratio versus moisture content relationship.

General characteristics of the S-curve and its determination procedure are described in detail in this paper, including presentation of the theoretical considerations, phase