Hello, everyone.
This is Enta.
For the past few days, I've been swamped with the design and cost estimation for a slope that suddenly collapsed...
Anyway, the one thing they always say is, “Pay up first!”
Wait...
No, no—we won’t get the money unless we figure out the construction methods and quantities first! Haha
Apparently, the government is saying, "Well, just make up your minds already!" They seem to be desperate to secure the budget, lol.
But that's beside the point.
Do you use different types of cement slurry in summer and winter?Are you doing that?
I do tend to use them a little differently.
1. When there is no construction schedule = Rapid-setting cement
2. When there is a construction schedule = ordinary cement
3. Cold Weather = Early-Strength Cement
4. When it's hot = Regular cement
5. When the injection distance is long = ordinary cement
6. When the injection distance is short = Either way
That's the gist of it.
When there's a tight schedule, it's hot, and the distance is long, we usually use cement.
That's the general idea.
When mixed with ordinary cement, the milk concentration is lower, so the flow rate increases.
That means it's suitable for long distances.
When used in cold weather, fast-setting cement hardens quickly due to its high heat of hydration, resulting in early strength.
However, workability decreases and the flow rate slows down.
Of course, the cost per bag of cement will go up.
So, the other day...
"What is the correct flow time for cement slurry in seconds?"
I think there are differences depending on the formulation, temperature, and equipment used.
"Are there any books you'd recommend?"
I received the following question.
The answer is: None.
Please consider the control values.
The target values set by railways, road authorities, and NEXCO range from 8 to 22 seconds.
It means that as long as it's included here, there's no problem.
The speed (in seconds) varies depending on the mix, temperature, and type of cement.
If the strength is confirmed within these control limits, this means that the quality can be verified to a certain extent.
Therefore, as long as the execution time falls within the target range, there is no particular issue.
This duration is specified in the “Ground Anchor Design and Construction Standards and Explanatory Notes” and
This information can be found in publications such as the “Manual for the Design and Construction of Soil Reinforcement Works for Natural Ground.”
There is generally no single "correct" number of seconds.
However, at this site, there is a standard for how many seconds is considered appropriate.
I'll cover that next time.
See you later.
