| Procedure | Equation | |
|---|---|---|
| GB/T 50081-2002 |  |
(5) |
| ACI 318-77 |  |
(6) |
| Dhir |  |
(7) |
| Mellmann |  |
(8) |
| Jing-hai |  |
(9) |
Note: Ec refers to the elastic modulus of concrete, Mpa; fcu refers to the cube compressive strength of concrete, Mpa; δ refers to the recycled concrete replacement ratio of recycled coarse aggregate