Yum Woo Sung, Do Jinung
Research Institute for Safety Performance, Korea Authority of Land and Infrastructure Safety (KALIS), Jinju 52856, Korea.
Department of Ocean Civil Engineering, Gyeongsang National University, Tongyeong 53064, Korea.
Materials (Basel). 2022 May 18;15(10):3620. doi: 10.3390/ma15103620.
Ground-granulated blast-furnace slag (GGBFS) can be used as a cementless binder after activation. Recent approaches to activate GGBFS have focused on chemical methods that use NaOH, KOH, and CaO. This study introduces the use of bacteria to activate GGBFS as a biological approach. The presence of bacteria (volumetric ratio), curing temperature (23 °C and 60 °C), and number of curing days (3, 7, and 28 d) are investigated. The use of urea is considered owing to the possibility of calcium carbonate formation. The activated GGBFS is evaluated in the form of a cube (5 cm × 5 cm × 5 cm) for its strength, mineral identification, and pore size distribution. A brick (19 cm × 9 cm × 5.7 cm) is prefabricated to see the feasibility of commercializing bacteria-activated GGBFS based on water absorption and strength measurements. All results are compared with those of water-activated GGBFS. The results indicate that the use of urea inhibits the strength improvement of bacteria-activated GGBFS. Bacterial suspension enhances the GGBFS strength at a curing temperature of 60 °C. Mineral identification tests show that the strength increase is primarily due to the formation of calcite. The compressive strength satisfies the commercial standard of concrete bricks; however, the water absorption rate must be resolved.
粒化高炉矿渣（GGBFS）在活化后可作为无水泥粘结剂使用。最近活化GGBFS的方法主要集中在使用氢氧化钠、氢氧化钾和氧化钙的化学方法上。本研究引入利用细菌来活化GGBFS作为一种生物方法。研究了细菌的存在（体积比）、养护温度（23℃和60℃）以及养护天数（3天、7天和28天）。考虑使用尿素是因为有可能形成碳酸钙。对活化后的GGBFS以立方体（5厘米×5厘米×5厘米）的形式进行强度、矿物鉴定和孔径分布评估。预制一块砖（19厘米×9厘米×5.7厘米），通过吸水率和强度测量来考察细菌活化GGBFS商业化的可行性。所有结果均与水活化GGBFS的结果进行比较。结果表明，尿素的使用抑制了细菌活化GGBFS强度的提高。细菌悬浮液在60℃的养护温度下提高了GGBFS的强度。矿物鉴定试验表明，强度增加主要是由于方解石的形成。抗压强度满足混凝土砖的商业标准；然而，吸水率问题必须解决。
