Why most of engineers always are using diagonal reinforcement for coupling beam ?!!
ACI318 need to satisfy the coupling beam requirements just in chapter 18 for a special walls so coupling beam connects two special walls in high seismic regions .
So if you have a beam connecting two ordinary shear walls , it can be designed as a normal beam for internal forces without diagonal rebars !!!!
Check seismic design category before starting to design any structures to know what is the minimum requirements as per ACI Code 318-19
