sand casting is used for that. you use stamps to make a design or shape the wet sand. then you tilt them up on one end and hoist them into place vertically..
on larger commerrcial tilt up buildings these are 8" or more thick, 20 or 30' long and 10 to 20 feet wide wide and weigh many tons. they are poured with one end in the cleat cast into the building slab, then the far end lifted with a crane..
these are also poured in a thin layer of sand, or with humps in it to shape the wall, laid with rope often, or various kinds of decorative stone.
its called 'tilt up construction' as you have seen comonly no doubt.
what you are doing is a lot smaller scale. with smaller panels on a one story structure two or three men could do the tilt up,
Most comon concrete strenthener is fine silcone.. but its expensive, not cheap at all. its used only in rare cases. carbon fiber would be about the same.
for house panels there is very little load. You would use just plain 150 lb concrete and only half an inch thick, with chicken wire.,, in the wall panels (as you mention in tennis type rackets) there is no stress fatigue or progressive cracking of the wire.. thats been established.
Myself Id make the panels half inch thick. then spray on an inch of urethane foam, then erect it while its light. when erected Id overspray the engiire sructure with half inch of stucco,
and hand trowl for a finish or whatever,
that covers all the sins with inperfect fit etc. allowing for very fast construction,
The cement hull boats are built with one or two layers of 1/4" rebar, extra around the top edge. some use fine silicone (waste product from cutting silicon wafers in the semi conductor industry).
Corrosion is the big issue with boat hulls. and the beating they take at sea.
for house panels you have none of that.