Create: Limited

{
  "values": {
    "create:water_wheel": {
      "repairItems": ["#minecraft:wooden_slabs"],
      "replaceWith": "minecraft:oak_planks",
      "decayProgressTime": 14400
    },
    "create:large_water_wheel": {
      "repairItems": ["#minecraft:wooden_slabs"],
      "decayProgressTime": 28800
    },
    "create:steam_engine": {
      "repairItems": ["minecraft:copper_ingot"],
      "decayProgressTime": 172800
    },
    "create:windmill_bearing": {
      "repairItems": ["minecraft:cobblestone"],
      "decayProgressTime": 43200
    }
  }
}

can be changed via datapack in 

data.create_limited.create_limited.decay_data

this is currently a placeholder and set to beta, there'll be a semi-major recode