Ünsal Zeynep, Ekinci Mehmet Özkan, İlcan Hüseyin, Şahin Oğuzhan, Selçuk Seda, Şahmaran Mustafa
Institute of Science, Hacettepe University, Beytepe, Ankara, Turkey.
Department of Civil Engineering, Hacettepe University, Beytepe, Ankara, Turkey.
Environ Res. 2025 Nov 15;285(Pt 2):122359. doi: 10.1016/j.envres.2025.122359. Epub 2025 Jul 17.
This study assessed the environmental impacts of construction and demolition waste (CDW)-based geopolymers. For analysis, the cradle-to-gate system boundary was established. Two different geopolymer mixtures were evaluated: one composed entirely of CDW-based precursors-(CDW100), and another incorporating supplementary cementitious materials-(SCMs) as a 20 % replacement of CDW-based precursors- (CDW80SCM20). Raw materials were sourced from a diverse range of demolition waste. NaOH and Ca(OH) were employed as activators. Additionally, a cementitious mixture with comparable strength was included in the analysis as a benchmark for comparison with the geopolymers. The results of the impact analyses revealed that CDW80SCM20 had a greater environmental impact across various categories compared to CDW100. The relatively higher environmental impacts of the CDW80SCM20 mixture are largely attributed to the transport-related environmental burdens associated with the inclusion of SCMs. The largest differences were for land occupation and global warming, at 30.8 % and 16.9 %, respectively. Moreover, the results indicated that the environmental impacts of the CDW-based mortars were significantly lower than those of the cementitious system, with the exception of aquatic eutrophication and ozone layer depletion. The increase in ozone layer depletion is mainly associated with the production of NaOH via the chlor-alkali process, which contributes to emissions affecting stratospheric ozone. The advantages of geopolymers in terms of environmental impact made it possible to reduce the effects of global warming by 48.1 %, aquatic acidification by 22.1 %, land occupation by 45.2 %, and non-renewable energy consumption by 1.83 %. However, aquatic eutrophication and ozone layer depletion were found to be higher compared to cementitious mortar.
本研究评估了基于建筑拆除废物（CDW）的地质聚合物的环境影响。为进行分析，建立了从摇篮到大门的系统边界。评估了两种不同的地质聚合物混合物：一种完全由基于CDW的前驱体组成（CDW100），另一种掺入了辅助胶凝材料（SCMs），替代20%的基于CDW的前驱体（CDW80SCM20）。原材料来自各种拆除废物。使用NaOH和Ca(OH)作为活化剂。此外，分析中还纳入了一种具有可比强度的胶凝混合物，作为与地质聚合物比较的基准。影响分析结果表明，与CDW100相比，CDW80SCM20在各个类别中具有更大的环境影响。CDW80SCM20混合物相对较高的环境影响主要归因于与掺入SCMs相关的运输相关环境负担。最大差异在于土地占用和全球变暖，分别为30.8%和16.9%。此外，结果表明，除了水体富营养化和臭氧层损耗外，基于CDW的砂浆的环境影响明显低于胶凝系统。臭氧层损耗的增加主要与通过氯碱工艺生产NaOH有关，这导致了影响平流层臭氧的排放。地质聚合物在环境影响方面的优势使得全球变暖影响降低了48.1%，水体酸化降低了22.1%，土地占用降低了45.2%，不可再生能源消耗降低了1.83%。然而，发现水体富营养化和臭氧层损耗比胶凝砂浆更高。
