The R510 APs support Ruckus SmartMesh. Therefore I would recommend enabling SmartMesh, with either Unleashed, Ruckus Cloud or SmartZone controllers and purchasing a suitable Ruckus outdoor AP (e.g. T310 or T350) to deploy outdoor.
Please note, you will need a good SNR outdoors from your existing APs for a good Mesh connection to establish. 25dB SNR @ 5GHz is a good starting point, you should be able to measure this using a free Wi-Fi 'sniffing' tool for your laptop. Don't use a phone to measure as it will (usually) give you a weaker signal.