Refining the Simple Performance Tester for Use in Routine Practice (2008) / Chapter Skim
Currently Skimming:
Pages 27-34
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 27... ...
Appendix A presents a draft standard practice for preparing SPT test specimens. First, tall gyratory specimens must be prepared to an air void content that is 1 to 2 percent higher than the desired air void content of the test specimen.
|
From page 28... ...
Although the Shedworks approach was considered to be more risky, it had the potential to automate and simplify the specimen fabrication operations and thereby accelerate the implementation of the SPT. The system proposed by Pine represented only a marginal improvement over available equipment, and did not address the primary objective of the Simple Performance Test Specimen Fabrication System, which was to automate and simplify the specimen fabrication operations.
|
From page 29... ...
During testing by the research team, it was determined that this chuck was not acceptable. Gyratory specimens loosened in the chuck approximately 50 percent of the time, and when this occurred, a test specimen could not be obtained.
|
From page 30... ...
The machine is capable of completing the sawing and coring operations within the specified time of 15 min. The first step in preparing a test specimen with the FlexPrep™ is to secure the gyratory specimen in the chuck of the machine.
|
From page 31... ...
First, the cutoff blades are advanced to trim the specimen ends. Once the ends are trimmed, the cutoff blades retract, and the core barrel advances from the bottom to core the test specimen.
|
From page 32... ...
4.2.3.2 Specimen Dimensions One of the objectives of the specification compliance testing was to investigate the effect of several specimen variables on the finished dimensions of specimens fabricated with the FlexPrep™ system. The planned experiment included different binder grades, different nominal maximum aggregate sizes and aggregate hardness, high and low air void content specimens, and gyratory specimens compacted to two heights.
|
From page 33... ...
This is likely the result of the air void gradient produced by the Interlaken compactor used to fabricate the gyratory specimens for this study. The Interlaken compactor produces high air voids at the top of the specimens and low air voids at the bottom.
|
From page 34... ...
The water heats sufficiently that specimens made with soft binders and high air void contents may creep beyond the range of the self-tightening chuck or break while being cored. • Test specimen removal.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.