The role of cement service-life on the efficient use of resources

The high demand for cement-based materials to support building and infrastructure systems is of growing concern as the production of cement leads to significant greenhouse gas (GHG) emissions and notable resource demand. While improved efficiency of cement use has been proposed as a means to mitigate these burdens, the effects of increasing longevity of cement in-use remains a poorly studied area. This work quantitatively explores the implications of using cement for a longer in-use residence times. Specifically, this work uses dynamic material flow analysis models to quantify the in-use stock of cement in the United States from 1900 to 2015. With these models, the implications of increasing or decreasing mean longevity of in-use cement on required cement production, demand for batching water, aggregates, and energy for cement-based materials, and GHG emissions are quantified. This work shows that a 50% increase in cement longevity could have led to a 14% reduction in material resource demand and GHG emissions from concrete production in the United States, equivalent to 0.28 to 0.83 Gt of batching water, 2.9 to 7.6 Gt of aggregates, 1E + 06 to 2.3E + 06 TJ of energy, and 0.4 to 0.7 Gt of CO₂-eq emissions. This percent reduction exceeds goals for reducing GHG emissions through alternative energy resources, suggesting improving durability and longevity of in-use cement stock could be a critical means to mitigating environmental impacts. (letter)