If there is a problem with the sand source, fine sand and some machine-made sand can be used to prepare pumpable concrete.
For example, fine sand with a fineness modulus less than 2.
0 can be mixed with machine-made sand with a fineness modulus of 3.
0-3.
2 in a ratio of about 6:4.
The flowability and pumpability can be observed, and the specific ratio can be determined through experiments.
.