Kim Jin-Hyoung, Lee Han-Seung
Department of Architectural Engineering, Hanyang University, 68 Munam 1-ga, Dong Nam-gu, Cheonan-si 31065, Chungcheongnam-do, Korea.
Department of Architectural Engineering, Hanyang University, 55, Hanyangdaehak-ro, Sangrok-gu, Ansan-si 15588, Gyeonggi-do, Korea.
Materials (Basel). 2017 Sep 7;10(9):1050. doi: 10.3390/ma10091050.
In the field of construction, securing the early strength of concrete (on the first and third days of aging) has been an important problem in deciding the mold release time (i.e., shortening the construction time period). Therefore, the problem of reduced compressive strength in the early aging stage caused by mixing granulated blast furnace slag (GBFS) with concrete must certainly be resolved. In this study, we conduct experiments to explore methods for generating a concrete that develops an early strength equivalent to that of 100% OPC. The objective of this study is the development of an early-strength accelerator (ESA) made from an industrial by-product, for a GBFS-mixed cement mortar. This study also analyzes the mechanism of the early-strength generation in the concrete to evaluate the influence of the burning temperature of ESA on the optimal compressive strength of the concrete. According to the results of the experiment, GBFS, whose ESA is burnt at 800 °C, shows an activation factor of 102.6-104.7% in comparison with 100% OPC on the first and third days during early aging, thereby meeting the target compressive strength. The results of the micro-analytic experiment are as follows: ESA showed a pH of strongly alkaline. In addition, it was found that the content of SO₃ was high in the chemical components, thus activating the hydration reaction of GBFS in the early age. This initial hydration reaction was thought to be due to the increase in the filling effect of the hydrate and the generation of C-S-H of the early age by the mass production of Ettringite.
在建筑领域，确保混凝土的早期强度（在龄期第一天和第三天）一直是决定脱模时间（即缩短施工周期）的一个重要问题。因此，必须解决因将粒化高炉矿渣（GBFS）与混凝土混合而导致早期龄期抗压强度降低的问题。在本研究中，我们进行实验以探索制备一种早期强度与100%普通硅酸盐水泥（OPC）相当的混凝土的方法。本研究的目标是开发一种由工业副产品制成的早期强度促进剂（ESA），用于掺加GBFS的水泥砂浆。本研究还分析了混凝土早期强度产生的机理，以评估ESA煅烧温度对混凝土最佳抗压强度的影响。根据实验结果，其ESA在800℃煅烧的GBFS在早期龄期的第一天和第三天与100%OPC相比，活性因子为102.6 - 104.7%，从而达到目标抗压强度。微观分析实验结果如下：ESA呈强碱性pH值。此外，发现其化学成分中SO₃含量较高，从而在早期龄期激活了GBFS的水化反应。这种初始水化反应被认为是由于钙矾石大量生成导致水化物填充效应增加以及早期C-S-H生成所致。
