Purpose This study assesses the effect of including CO 2 uptake by cement-containing materials (CCM) in background life cycle inventories, on comparative life cycle assessments. Methods The carbonation of CCM consumed by transforming activities in the ecoinvent database is estimated. The uncertainties around parameters that affect cement carbonation (e.g., geometry and environment types) are approximated by error propagation. Five pairwise comparisons of functionally equivalent product systems are conducted in two parallel Monte Carlo simulations to isolate the effect of cement carbonation using pre-sampled values. Results and discussion Based on the five comparative assessments, there is a maximum probability of 3.7% that including cement carbonation in background inventories of ecoinvent can affect end results to the extent of changing conclusions. While a probability of 3.7% is admittedly low, this finding is exclusively based on ecoinvent inventories. Therefore, should the inventories rely on background activities that consume CCM to a larger extent, or from another database, this probability may be higher. Conclusions It is difficult to state whether including cement carbonation in background inventories is likely to significantly change the outcome of a comparative study. It seems though that neglecting cement carbonation in background inventories currently creates, at best, a mild bias in favor of CCM-poor product systems. Given the clear and easy-to-implement method presented in this study, the authors recommend including cement carbonation in the future development of life cycle inventory databases.

中文翻译：

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我们应该忽略生命周期清单数据库中的水泥碳化吗？

目的 本研究评估将含水泥材料 (CCM) 吸收的 CO 2 纳入背景生命周期清单对比较生命周期评估的影响。方法 估算在ecoinvent 数据库中转化活动消耗的CCM 的碳化。影响水泥碳化的参数（例如几何形状和环境类型）的不确定性通过误差传播来近似。在两个平行的 Monte Carlo 模拟中进行了功能等效的产品系统的五个成对比较，以使用预采样值隔离水泥碳化的影响。结果与讨论 根据五次比较评估，最大概率为 3。7% 的人认为，在 Ecoinvent 的背景清单中包括水泥碳化会影响最终结果，从而改变结论。虽然 3.7% 的概率确实很低，但这一发现完全基于生态发明库存。因此，如果清单在更大程度上依赖于消耗 CCM 的后台活动，或者来自另一个数据库，则此概率可能更高。结论 很难说明将水泥碳化纳入背景清单是否可能显着改变比较研究的结果。尽管目前在背景清单中忽略水泥碳化，充其量只会产生轻微的偏向于支持低 CCM 产品系统。鉴于本研究中提出的清晰且易于实施的方法，