Activation of blast furnace slag by a new method
Activation of blast furnace slag by a new method
复制标题
DOI：
10.1016/j.cemconres.2009.05.012
复制
发表时间：
2009-08-01
影响因子：
11.4
通讯作者：
Stark, J.
中科院分区：
文献类型：
--
作者：
Bellmann, F.;Stark, J.
高炉矿渣作为辅助胶凝材料，用于生产混合水泥和矿渣水泥。其潜在的水硬特性可以通过多种方法激活。大多数应用采用孔隙溶液中的高pH值（> 13.0）来加速炉渣玻璃网络的腐蚀。这项工作表明，通过添加氢氧化钙和可溶性钙盐将pH值降低到11.8和12.2之间的范围也可以进行活化。本研究研究的盐包括氯化钙、溴化钙、硝酸钙、甲酸钙和醋酸钙。也可以使用其他盐，只要它们能够增加钙离子浓度，从而通过氢氧化钙平衡降低孔隙溶液中的pH值。当使用有机钙盐时，有机阴离子与孔隙溶液中的钙离子形成络合物是一个严重的障碍。这个概念在一种特定的炉渣上进行了测试，以提高其早期抗压强度。通过添加氢氧化钙、碳酸钙和醋酸钙，7天后可以将纯矿渣生产的砂浆棒的强度从3 MPa提高到25 MPa。通过添加氯化钙，含80%矿渣的矿渣水泥的早期强度在两天后从6兆帕增加到16兆帕。 28 天后，最终强度从 36 MPa 增加到 53 MPa（水/水泥比 = 0.40，20 摄氏度）。分析数据表明上述概念的应用能够增加放热和炉渣消耗程度。 (C) 2009 Elsevier Ltd. 保留所有权利。
Blast furnace slag is used as supplementary cementing material for the production of blended cement and slag cement. Its latently hydraulic properties can be activated by several methods. Most applications employ the use of high pH values in the pore solution (> 13.0) to accelerate the corrosion of the glass network of the slag.It is shown in this work that activation is also possible by lowering the pH to a range between 11.8 and 12.2 by the addition of calcium hydroxide and soluble calcium salts. Among the salts investigated in this study are calcium chloride, calcium bromide, calcium nitrate, calcium formate, and calcium acetate. Other salts can be used alternatively as long as they are able to increase the calcium ion concentration and thus reduce the pH in the pore solution via the calcium hydroxide equilibrium. Complex formation of organic anions with calcium ions in the pore solution is a serious handicap when using organic calcium salts. This concept was tested on a particular slag improving its early compressive strength. It was possible to increase the strength of mortar bars produced from the pure slag from 3 MPa to 25 MPa after seven days by adding calcium hydroxide, calcium carbonate and calcium acetate. The early strength of slag cement containing 80% slag was increased from 6 to 16 MPa after two days by adding calcium chloride. The final strength was increased from 36 to 53 MPa after 28 days (water/cement-ratio = 0.40, 20 degrees C). Analytical data is included to demonstrate that application of the aforementioned concept is able to increase heat liberation and degree of slag consumption. (C) 2009 Elsevier Ltd. All rights reserved.