混凝土基本组分吸收二氧化碳的能力(英文)

研究了利用混凝土产品吸收二氧化碳的可行性。混凝土的3个基本组分:水泥、细沙和骨料,都可被用来作为二氧化碳吸附物以实现储留最大化,另外,可利用高钙钢渣等工业废料生产混凝土骨料。研究发现波特兰水泥2h碳化后吸收14%二氧化碳,碳化后的材料的强度与7d传统养护的强度相当。钢包钢渣细粉能吸收4%～12%二氧化碳,能用来替代河沙。吹氧高炉钢渣对二氧化碳吸收的能力超过12%。由此制成的粗骨料其强度可与石灰岩相比。如果混凝土砌块由这3组分组成,一块20cm×20cm×20cm的标准砌块能吸收1.39kg二氧化碳。二氧化碳在混凝土中的储留是一项经济可行、直接减排的有效技术。

CO2 UPTAKE CAPACITY OF CONCRETE PRIMARY INGREDIENTS

The feasibility of using concrete products to uptake carbon dioxide emitted from cement production were investigated. All three primary ingredients of concrete: cement binder, fine aggregates and coarse aggregates, are considered as CO2 absorbents to maximize carbon sequestration in concrete and produce concrete aggregates from calcium-containing steel slag. It is found that two-hour carbonation enabled the Portland cement can consume ≥14% of CO2, and its strength is comparable to that after 7 d con-ventional curing. Ladle slag fines could take 4%-12% of CO2 due to their smaller particle size and can be used as a substitution to natural river sand. Basic oxygen furnace (BOF) slag shows an excellent reactivity with CO2. The CO2 uptake capacity in manufac-tured coarse BOF slag aggregates reaches 12%. The solid BOF steel slag compact produced has a strength compared to crushed lime-stone. If all three solid components of concrete can be used to uptake CO2, one typical concrete masonry unit (CMU, 20 cm × 20 cm× 20 cm) can sequester 1.39 kg of CO2. Carbon sequestration in concrete is an economic and effective approach that directly reduces carbon emission from cement industry.