In a pre-tensioning scheme, the prestress load is transferred either in a single-stage process or a multi-stage process. Let's understand each of these processes in detail:

1. Single-stage process:
In a single-stage pre-tensioning process, the prestress load is applied to the tendons before the concrete is cast. The tendons, usually made of high-strength steel, are tensioned using hydraulic jacks or other tensioning devices. Once the tendons are tensioned, the ends are anchored to the concrete forms using anchorage devices. After the concrete is cast and cured, the tensioning force in the tendons is released, transferring the prestress load to the concrete. This process is commonly used in the precast concrete industry.

2. Multi-stage process:
In a multi-stage pre-tensioning process, the prestress load is transferred in multiple stages. This process is typically used when the size or shape of the structural member is large and requires additional control over the prestress force. The multi-stage process involves the following steps:
a) Partial tensioning: Initially, the tendons are tensioned to a certain predetermined load before the concrete is cast. This partial tensioning allows for better control over the concrete's behavior during the casting process.
b) Concrete casting: After the partial tensioning, the concrete is cast around the tendons. The tendons are positioned within the concrete to ensure optimal load transfer.
c) Final tensioning: Once the concrete has gained sufficient strength, the tendons are further tensioned to the desired final load. This final tensioning helps in achieving the required structural performance and mitigating any losses that may have occurred during the construction process.
d) Transfer of prestress load: Finally, the tensioning force in the tendons is released, and the prestress load is transferred to the concrete.

In summary, in a pre-tensioning scheme, the prestress load can be transferred either in a single-stage process or a multi-stage process. The choice of process depends on various factors such as the size and shape of the structural member, desired control over prestress force, and construction requirements. Both processes have their advantages and are widely used in different applications of pre-tensioned concrete.