Hello, everyone.

This is Enta.

The figure 1.24 m³ has been used for a long time in applications like sprayed mortar, hasn't it?

What is 1.24 m³ of sand?I get asked that.

Right now, the only information provided is a general mix ratio of 1:4 for spray mortar. (I wonder if they don't even list the mix ratio these days?)

In the past, it was mentioned quite often.

Sprayed Mortar (1:4) Cement: 420 kg Sand: 1,680 kg (1.24 m³)

Regarding 1.24,

Simply put, if you cram 1,680 kg in there as tightly as possible,

That comes out to 1,355 kg (which varies slightly depending on the specific gravity), which is 1.24 m³.

Basically, when you load sand onto a dump truck using a wheel loader (tire shovel),

This includes air and other voids, and its weight is 1,680 kg.

Since this is now the market price, it’s a figure that doesn’t come up very often, but,

In the past, these were the numbers used for cost estimation and quantity calculations.

I think the design figure is calculated by multiplying 1.24 m³ per 1 m³ by the loss rate.

Water-to-Cement Ratio (W/C) Double B.C.

For sprayed mortar work, 45–55% is the standard.

Since the summer brings extreme dryness and heat, we set the humidity to 55% to improve workability during construction.

In winter, it’s best to adjust the setting to around 49% to prevent freezing.

Since additives (water-reducing agents) have become particularly high-performance lately, we can expect to see improvements in quality through their use!

High-performance water-reducing agents are more effective than using low-quality antifreeze! (This is for sure.)

For high-performance water-reducing agents in the summer, we recommend FT700.

I think this is quite helpful for preventing cracks. (From experience)

See you later.