Have a look at a set for Unreal that features grenade effects for multiple surfaces. Free of charge in September!
The pack includes a collection of grenade explosion effects for a variety of surface types, including concrete, dirt, grass, ice, and more.
Surfaces:
Default
Air
Concrete
Dirt
Grass
Ice
Metal
Snow
Wood
Water
It also features a scorch decal, materials textures, and geo camera shake Blueprint, plus a grenade Blueprint that uses the effects. The author noted that all effects are a mixture of CPU, GPU and mesh emitters.