Andrade Carmen, Martínez-Serrano Ana, Sanjuán Miguel Ángel, Tenorio Ríos José Antonio
International Center of Numerical Methods in Engineering (CIMNE)-UPC, 28010 Madrid, Spain.
Institute of Construction Sciencies "Eduardo Torroja"-CSIC, 28033 Madrid, Spain.
Materials (Basel). 2021 Mar 8;14(5):1300. doi: 10.3390/ma14051300.
The Portland cement industry is presently deemed to account for around 7.4% of the carbon dioxide emitted annually worldwide. Clinker production is being reduced worldwide in response to the need to drastically lower greenhouse gas emissions. The trend began in the nineteen seventies with the advent of mineral additions to replace clinker. Blast furnace slag and fly ash, industrial by-products that were being stockpiled in waste heaps at the time, have not commonly been included in cements. Supply of these additions is no longer guaranteed, however, due to restrained activity in the source industries for the same reasons as in clinker production. The search is consequently on for other additions that may lower pollutant gas emissions without altering cement performance. In this study, bentonite, a very common clay, was used as such an addition directly, with no need for precalcination, a still novel approach that has been scantly explored to date for reinforced structural concrete with structural applications. The results of the mechanical strength and chemical resistance (to sulfates, carbonation and chlorides) tests conducted are promising. The carbonation findings proved to be of particular interest, for that is the area where cement with mineral additions tends to be least effective. In the bentonite-bearing material analysed here, however, carbonation resistance was found to be as low as or lower than that observed in plain Portland cement.
目前，波特兰水泥行业被认为占全球每年二氧化碳排放量的7.4%左右。为了大幅降低温室气体排放，全球范围内正在减少熟料产量。这一趋势始于20世纪70年代，当时出现了用矿物掺合料替代熟料的情况。高炉矿渣和粉煤灰作为工业副产品，当时被堆放在废料堆中，通常未被纳入水泥中。然而，由于与熟料生产相同的原因，这些来源行业的活动受到限制，这些掺合料的供应不再有保障。因此，人们正在寻找其他可能在不改变水泥性能的情况下降低污染物气体排放的掺合料。在本研究中，膨润土这种非常常见的粘土被直接用作此类掺合料，无需预煅烧，这是一种迄今在用于结构应用的钢筋结构混凝土中很少探索的新颖方法。所进行的机械强度和耐化学性（对硫酸盐、碳化和氯化物）测试结果很有前景。碳化结果尤其令人感兴趣，因为在这方面，含矿物掺合料的水泥往往效果最差。然而，在此处分析的含膨润土材料中，发现其抗碳化性能与普通波特兰水泥相当或更低。
