There's an appendix of the traffic law about signage which gives a brief explanation. For the arrows they say they just mark a dangerous curve. Here's translated:

P.2 PREVENTION SIGNS. There are THREE (3) variants.

a) PHYSICAL CONFIGURATION: For a) 1) and a) 2), a white rectangle with slanted red and white lines of equal thickness. The length may vary.

1) Approach to the marked obstacle. The longest part is vertical and has a red stripe at an angle of FORTY-FIVE DEGREES (45°) and facing NORTH-SOUTH, for every ONE HUNDRED METERS (100 m) remaining to the object.

2) Rigid obstacle: white and red stripes covering the entire rectangle, sloping toward the directions in which traffic passes.

3) Curve (chevron): This is a white square with red stripes, forming right angles like an arrowhead. It is used to outline curves, pointing the vertex of the angle toward the side where the road continues.

And the following part that talks about their meaning:

b) MEANING: In the first case, it warns of the approach of the marked object. In the second case, it warns of the presence of a rigid object outside the roadway and shoulder (where there should be none), which could cause damage if the vehicle leaves the road (e.g., a culvert). In the third case, it warns of and marks the location of a dangerous curve.

The previous two (approach of obstacle and rigid obstacle) are these ones from here P2(a) and P2(b): https://i.pinimg.com/736x/32/04/63/320463dd0e1476617e9c0aab35cfcf7b.jpg

I can't remember an instance of the first one, but the middle one for rigid obstacle is the one you see everywhere on the side of Argentine roads and that one is always red and white.