Carrier aggregation (CA) is one of the key features of LTE-Advanced. On one hand it allows to boost the system capacity and on the other hand it enables dynamic spectrum access, such as licensed assisted access (LAA) and licensed shared access (LSA). Efficiently exploiting CA is however not a trivial task; the main challenges are scheduling, load balancing, dynamic carrier activation/deactivation, etc. Due to the complexity of these systems, experimentation is needed to evaluate and test these features. OpenAirInterface is a well know open-source software defined radio solution that allows for experimentation with LTE 4G systems. In this paper we are going present two extensions of the current version of OpenAirInterface: Carrier Aggregation and an application programming interface (API) for schedulers that allows a third party to plug-in their own scheduler. These two extensions allow for more control in the experimentation process than with commercial equipment.