{"id":7767,"date":"2018-08-07T08:00:23","date_gmt":"2018-08-06T23:00:23","guid":{"rendered":"https:\/\/norimen.net\/wordpress\/?p=7767"},"modified":"2026-05-17T12:12:32","modified_gmt":"2026-05-17T03:12:32","slug":"hard-cement-milk-solution-1","status":"publish","type":"post","link":"https:\/\/norimen.net\/en\/hard-cement-milk-solution-1\/","title":{"rendered":"What to Do When Cement Slurry Is Too Thick (Part 1)"},"content":{"rendered":"

Hello, everyone.<\/p>\n

This is Enta.<\/p>\n

I just found out recently that even construction workers seem to be reading this blog!!<\/p>\n

I'm surprised.<\/p>\n

That\u2019s because it seems the earthwork crew at the same job site noticed me and came over to say hello!<\/p>\n

Actually, I thought that probably only slope engineers were looking at it, but,<\/p>\n

It's a little embarrassing knowing the construction workers are watching, lol.<\/p>\n

Since I'm the one reaching out, I won't know about any of you unless you contact me.<\/p>\n

Well, if we happen to run into each other somewhere, please say hi. Just work up the courage, lol.<\/p>\n

\n

But that's beside the point.<\/p>\n

Cement Slurry Formulation<\/h3>\n

When it's this hot, the cement slurry sets super fast!<\/p>\n

I was mixing it using the usual recipe, but quite a few lumps were forming on the edge of the mixer.<\/p>\n

\"Grout<\/p>\n

In the past, this was often included in design documents as a standard mix, but nowadays, for rebar insertion work\u2014which is now priced based on market rates\u2014it\u2019s rarely specified at all.<\/p>\n

The following is a traditional formulation that has been around for a long time. These days, it\u2019s mostly just listed as an example by materials manufacturers.<\/p>\n

 <\/p>\n\n\n\n\n
Ingredients<\/strong><\/span><\/td>\nCement<\/strong><\/span><\/td>\n\u6c34<\/strong><\/span><\/td>\nAdmixture<\/strong><\/span><\/td>\n<\/tr>\n
Mixing Ratios<\/strong><\/span><\/td>\n1,230 kg<\/strong><\/span><\/td>\n50\u201355%<\/strong><\/span><\/td>\n2% or more<\/strong><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

Generally speaking, the water-to-cement ratio is set at 50%, right?<\/p>\n

In fact, even at 55% during the summer, the strength is sufficient.<\/p>\n

But I'm still worried, so honestly, I don't really want to post this here, lol.<\/p>\n

Now, I\u2019ll explain how to make it so that it has good fluidity and high strength during the summer.<\/p>\n

Well, I guess that makes sense, but first of all...<\/p>\n

\"High-early-strength<\/p>\n

Use ordinary cement instead of fast-setting cement.<\/span><\/strong><\/p>\n

During the summer, even ordinary cement will reliably reach \u03b8 = 24 kN within seven days.<\/p>\n

On the other hand, depending on the region, there might even be people who\u2019ve only ever used regular cement! lol<\/p>\n

The Tokai region actually uses quite a bit of fast-setting cement. It\u2019s just common practice to use fast-setting cement there. (I don\u2019t know why.)<\/p>\n

If there is enough time in the construction schedule, regular cement is sufficient.<\/p>\n

When using ordinary cement, the mixture becomes runnier than when using high-early-strength cement, so its workability is quite high.<\/p>\n

Also, since it takes quite a while to cure, it makes the work easier.<\/p>\n

 <\/p>\n

Increase the amount of admixture<\/strong><\/span><\/p>\n

I think people generally only add about 2%, but it\u2019s actually effective up to about 4%!<\/p>\n

That said, according to the instructions in the LeoBuild 4000 catalog,<\/p>\n

The standard dosage is 2,000 mL of undiluted solution per 100 kg of cement, but depending on the intended use,<\/span><\/strong><\/span>
\nPlease use the undiluted solution in the range of 1,000 to 4,000 mL.<\/span><\/strong><\/span><\/p>\n

That's what it says.<\/p>\n

So, that means you can invest up to 4%.<\/p>\n

If you find that the fast-setting cement is too hard, do not dilute it with water.<\/p>\n

It's better to loosen it with a mixing agent.<\/p>\n

If diluted with water, there will be a significant decrease in strength.<\/span><\/strong><\/span><\/p>\n

When diluting, use a mixing agent!<\/span><\/strong><\/span><\/p>\n

Craftsmen don't really know much about that, so they tend to try to dilute it with water right away.<\/p>\n

Please absolutely do not do that.<\/p>\n

\"NO!\"<\/p>\n

If possible, please explain this to them\u2014that way, once they have this knowledge, they won\u2019t have to worry about insufficient strength in the future.<\/p>\n

Cement gains strength when less water is used.<\/span><\/strong><\/span>Please tell me about that.<\/p>\n

\"Demerit\"<\/p>\n

However, there is a downside: if you add too much admixture...<\/p>\n

The salt concentration increases quite a bit.<\/span><\/strong><\/span><\/p>\n

That said, since the rebar insertion fittings are already hot-dip galvanized, it shouldn\u2019t really be a concern, but,<\/p>\n

This is a bit of a problem from an administrative standpoint... Please be careful when using Kantab.<\/p>\n

 <\/p>\n

Some interesting results have emerged from research on salt concentration and carbonation, so I thought I'd share them for your reference.<\/p>\n

Understanding the Effect of Salt Content in Hardened Cement on Neutralization<\/span><\/span><\/strong><\/span><\/a>\u3000The Japan Society of Civil Engineers<\/p>\n

 <\/p>\n

There's one more, so I'll save that for tomorrow!<\/p>\n

 <\/p>\n

See you later.<\/p>\n

Lowering Workability Improves Productivity | A Paradox<\/a><\/p><\/blockquote>\n