On the Theoretical CO2 Sequestration Potential of Pervious Concrete
On the Theoretical CO2 Sequestration Potential of Pervious Concrete
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DOI：
10.3390/infrastructures4010012
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发表时间：
2019-03
期刊：
影响因子：
2.6
通讯作者：
Ethan Ellingboe;J. Arehart;W. Srubar
中科院分区：
文献类型：
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作者：
Ethan Ellingboe;J. Arehart;W. Srubar
透水混凝土最近在建筑中得到了新的应用，它的制造既耗能又碳密集。然而，与普通混凝土类似，与透水混凝土相关的一些初始二氧化碳排放可以通过称为碳酸化的过程被隔离。在这项工作中，提出了用于估计透水混凝土封存二氧化碳（CO2）潜力的数学模型的理论公式和应用。使用水泥和碳酸化化学原理，模型相关的透水混凝土的混合比例，其理论原位CO2封存潜力。该模型随后采用筛选生命周期评估（LCA），以量化可回收的CO2排放量的百分比，即原位封存CO2初始摇篮到门CO2排放量的比例，为常见的透水混凝土混合物。结果表明，自然碳酸化可以恢复高达12%的初始CO2排放量和CO2封存潜力最大化的透水混凝土混合物（一）较低的水灰比，（二）较高的抗压强度，（三）较低的孔隙率，和（四）较低的水力传导率。然而，LCA结果阐明，具有最大CO2封存潜力的混合物（即，具有高水泥含量和CO2可回收性的混合物）从净排放的角度来看会排放更多的CO2，尽管它们增强了原位CO2封存潜力。
Pervious concrete, which has recently found new applications in buildings, is both energy- and carbon-intensive to manufacture. However, similar to normal concrete, some of the initial CO2 emissions associated with pervious concrete can be sequestered through a process known as carbonation. In this work, the theoretical formulation and application of a mathematical model for estimating the carbon dioxide (CO2) sequestration potential of pervious concrete is presented. Using principles of cement and carbonation chemistry, the model related mixture proportions of pervious concretes to their theoretical in situ CO2 sequestration potential. The model was subsequently employed in a screening life cycle assessment (LCA) to quantify the percentage of recoverable CO2 emissions—namely, the ratio of in situ sequesterable CO2 to initial cradle-to-gate CO2 emissions—for common pervious concrete mixtures. Results suggest that natural carbonation can recover up to 12% of initial CO2 emissions and that CO2 sequestration potential is maximized for pervious concrete mixtures with (i) lower water-to-cement ratios, (ii) higher compressive strengths, (iii) lower porosities, and (iv) lower hydraulic conductivities. However, LCA results elucidate that mixtures with maximum CO2 sequestration potential (i.e., mixtures with high cement contents and CO2 recoverability) emit more CO2 from a net-emissions perspective, despite their enhanced in situ CO2 sequestration potential.