My guess for the extra axle is the weight, cement trucks have a very high front axle rating, US DOT allows an exemption on front axle weight just for cement mixers (IIRC front axle is normally 12,000 lbs, but its 20,000 for cement mixers). They often have much wider tires on the front than the rear to support the weight. So possibly not all countries allow the extra weight up front or some places put an extra axle up front for longer life? Just a guess on my part, maybe the builder just thought it looked cool.
Anyway the truck looks great, and the dual front axle is different.