This paper introduces research to develop an intelligent microwave system for manufacturing concrete products. The key features of this system include the use of optical fibre Bragg grating sensors to control the temperature and humidity inside the concrete and microwave oven cavity respectively. Using this tailor-made microwave system, research is ongoing in the Advanced and Innovative Materials Group at University College London to explore the potential for curing two types of low-carbon cementitious systems: high-volume fly ash and alkali-activated fly ash. In both systems, thermal curing is essential for strength development, particularly early strength development. Results indicate that, by using the microwave curing technique, low-carbon performance can be achieved from both systems, whilst early strength was not affected. The results demonstrate the potential of microwave curing for manufacturing low-carbon precast concrete elements in future