Smart green railway sleepers

Concrete railway sleepers have high performance requirements but currently have a relatively high environmental impact. Performance requirements are currently met with concrete mixes using a high proportion of Portland cement, leading to a high embedded CO2 content (150,000 t/annum). Approximately 1 million sleepers are produced every year with a similar number reaching the end of their in-service life (this number equates to about 200,000 tonnes of concrete annually). The lack of data on the raw material base and sleeper history prevents sleepers, or their component parts, being recycled at end of life. The project will reduce lifecycle environmental impacts of sleepers whilst maintaining performance characteristics. It will achieve this objective by a) developing innovative concrete mixes to reduce embodied CO2 and b) developing ICT-based solutions using embedded sensors to reduce waste in the supply chain and enable through-life monitoring to support 'circular' reuse/recycling at the end of life. A 50% reduction in embedded CO2 and 50% recycling rate are targetted within 5 years.