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A huge number of specimens are built. For each specimen, soil is mixed with cement (and Zeolite) with different percentages. It's intended to test, measure and compare the impact strength of the specimens.

One test option

One test approach is to drop a ball on the specimens and count the number of drops before the specimen collapses/breaks. There is a problem with that, some specimens require hundreds of the drops before collapsing/breaking. Dropping the ball for hundreds of times is done manually which is a daunting task for the students doing the test.

Drop ball test

Question

I wonder if there is any other approach for testing which as cheap, but less of a manual work?

Students can build simple devices. Is there any design for a simple device which can do the test automatically, i.e. without the need for dropping the ball manually hundreds of times?

Thanks =)

Ball size

We cannot use a larger ball to reduce the drop count. Since some specimens are breaking with a few ball drops :(

user3405291
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    https://youtu.be/IvUU8joBb1Q – jsotola Jul 01 '22 at 16:15
  • Tests like this usually drop a specific weight once . If the sample is not damaged , it has passed the test. – blacksmith37 Jul 01 '22 at 16:18
  • @jsotola Cool =) – user3405291 Jul 02 '22 at 12:08
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    Fracture point is a highly nonlinear process, so it matters **a lot** whether you are testing against expected drop loads or looking for the maximum single drop impulse force the sample can sustain. Make sure you know what the intent of your test is. – Carl Witthoft Jul 05 '22 at 12:36
  • @CarlWitthoft Thanks :) Our understanding of your comment is that we should note whether we are trying to measure fatigue strength or whether we intend to measure single impact strength. Did we understand your point correctly? – user3405291 Oct 21 '22 at 16:26

1 Answers1

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It sounds like you could modify the procedure and equipment used for a soil standard penetration test (ASTM D1586). In this test, a hammer of specific weight is dropped a specific distant to strike a rod. The test is automated in that the hammer is re-raised mechanically.

hazzey
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