i have been considering putting paving stones/block on the grounds around the house since weeds
grow very fast, and the line trimmers cant keep up. But i found this on the internet while looking
for cheaper options.

and found this while looking for even cheaper options.

to build this

Now on further trying to keep cost down, i thought that what if i pour a 3:2:1 mix, and then just
before filling up the mold, pour in a mix of 2:1 sand:cement mix. This is so that the surface will
have a smother finish and that no aggregate(gravel etc.) will show on top. Kind of like palitada,
only the top layer is poured on while the bottom is still wet.

How would this affect the strength of the concrete? is there a chance that the Top part will crack,
just like how palitadas are?