Hello, everyone.

This is Enta.

I'm now using WordPress instead of Shin-Ent's Slope Management Course, but,

I still haven't gotten used to it yet, lol.

I’ve been writing on Ameblo for eight years now. Getting used to something can be kind of scary, lol.

I don't really know how to use this software lol

I'm thinking I'll start by writing about getting used to things first.

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But that's beside the point.

There are quite a few people who have a misunderstanding about the strength test for cement slurry.

Regarding the standards for compressive strength testing in rock bolting and anchoring work,

Quality control standards generally include:Twice a day (morning and afternoon)It says so.

So, this is where the problem starts, but,

When using ordinary cement,3 in the morning, 3 in the afternoon　That's it.

There are people here who take six bottles every time, for a total of 12 bottles a day.

In the event that the desired strength is not achieved (which may vary depending on the manufacturing process),SpareI don't think there's a problem with that.

The standard is 4 weeks (28 days) of intensity. There is no need for intensity during the first week.

 

Next, let's consider the case where rapid-setting cement is used.

In the case of fast-setting cement,

4-week strength of ordinary cement = 1-week strength of fast-setting cement

1-week strength of ordinary cement = 3-day strength of fast-setting cement

Therefore, when using the "Early-Intensity" method, we'll use the intensity of Week 1 as the baseline.

However, if early-age tensile tests or similar tests are conducted to shorten the construction schedule, a 3-day strength value is required.

To get nervousIt must meet the design strength requirement of 24 kN.is required.

Therefore, this means checking the intensity every three days and performing the exercise, and then checking the intensity once a week.

 

Just because the design strength is achieved in three days doesn't mean a week isn't needed.

It will take one week. We need to standardize the criteria.

 

In my case, I don't take very many.

Recent tests have become more accurate, so it’s rare for the strength to be significantly lower than expected.

Taking too many will only drive up costs.

 

Do you know about grinders for test specimens?

This polishing machine is incredibly high-performance.

But! It's just so expensive, though,

Make the test surface smooth during the compressive strength test to prevent uneven loading.

I'm planning to buy one eventually, but I can't afford it just yet lol

As expected, we can't make a purchase unless the main contractor and first-tier subcontractors are the primary parties involved.

Generally, at public auto repair shops, a single-surface polish costs between 1,000 and 1,500 yen.

For example, for frame work, 6 units per day (12 surfaces total, upper and lower) costs 12,000 yen (1,000 yen per unit).

120,000 yen for a spray job on the 10th?

 

By the way, this polishing machine costs about 1 million yen lol.

 

Well, that's it for now.