Influence of chemical and physical characteristics of cement kiln dusts (CKDs) on their hydration behavior and potential suitability for soil stabilization

The interaction of CKDs with a given soil depends on the chemical and physical characteristics of the CKDs. Hence, the characterization of CKDs and their hydration products may lead to better understanding of their suitability as soil stabilizers. In the present article, four different CKD powders are characterized and their hydration products are evaluated. A detailed chemical (X-ray diffraction), thermogravimetric and morphological (scanning electron microscope) analyses of both the CKD powders and the hydrated CKD pastes are presented. In general, high free-lime content (~ 14–29%) CKDs, when reacted with water produced significant amounts of calcium hydroxide, ettringite and syngenite. These CKDs also developed higher unconfined compressive strength and higher temperature of hydration compared to CKDs with lower amounts of free-lime. An attempt was made to qualitatively correlate the performance of CKD pastes with the chemical and physical characteristics of the original CKD powders and to determine their potential suitability as soil stabilizers. To that effect a limited unconfined compressive strength testing of CKD-treated kaolinite clays was performed. The results of this study suggest that both the compressive strength and the temperature of hydration of the CKD paste can give early indications of the suitability of particular CKD for soil stabilization.     

竖曲线在圆曲线测设中的应用

根据多年的施工经验,总结了一套利用竖曲线计算圆曲线的方法,分析了竖曲线的计算原理,介绍了圆曲线测设的步骤,探讨了该法的适用范围,同时指出该法既方便迅速又不需浪费人工,值得推广使用。     

Vertical versus shared leadership as predictors of the effectiveness of change management teams: An examination of aversive, directive, transactional, transformational, and empowering leader behaviors.

This study investigated vertical versus shared leadership as predictors of the effectiveness of 71 change management teams. Vertical leadership stems from an appointed or formal leader of a team, whereas shared leadership (C. L. Pearce, 1997; C. L. Pearce & J. A. Conger, in press; C. L. Pearce & H. P. Sims, 2000) is a group process in which leadership is distributed among, and stems from, team members. Team effectiveness was measured approximately 6 months after the assessment of leadership and was also measured from the viewpoints of managers, internal customers, and team members. Using multiple regression, the authors found both vertical and shared leadership to be significantly related to team effectiveness (p     

外火箱矩形竖窑进火孔的改进与施工

介绍了外火箱矩形竖窑进火孔改造前的使用情况以及改造的必要性 ;阐述了进火孔改造的设计施工和试验情况 ,并在 15 0 0～ 16 0 0℃时对物料的烧结作了成功的尝试 ,解决了因进火孔堵塞影响窑炉寿命和产品质量的问题。     

立式模压橡胶防尘套模具设计

介绍了薄壁橡胶防尘套采用立式哈夫式结构的必要性、生产工艺流程及辅助工装的设计与工作过程     

立磨机细磨重质碳酸钙的试验研究

立磨机可成功地用于磨制超细重质碳酸钙，影响其工作的主要因素的转速，浓度，介质量，介质种类及助磨剂等，立磨机效率高，能耗低。     

回转窑内物料流动模型研究

着重研究L/D≥ 10的回转窑内颗粒的运动 ,采用颗粒受力矢量分析确定单颗粒运动轨迹 ,从而推出单历程颗粒的位移和时间。然后引进差补方法计算物料平均轴向位移和平均停留时间 ,并分析了物料充满角对轴向位移速度的影响。同时对几种固体废弃物进行了流动试验 ,实验结果与理论分析得出的公式吻合较好。     

立式油罐换底施工方法浅析

介绍了立式油罐换底的几种方法;分析了其优劣之处;具体介绍了加层法的施工实例及施工步骤。     

熟料窑运行状态检测应用研究

阐述了对回转窑运行轴线进行监测的重要性 ;介绍了一种回转窑运行轴线监测的研究成果 ,该方法采用 15°方向键相法测量窑体截面的回转中心 ,通过对窑各挡支承轮带两侧的截面测量而获得运行轴线 ;研制的监测系统结构简单 ,运行可靠 ,监测精度高 ,操作、使用、维护方便 ,并成功地应用于实际生产中     

V2O3回转窑的国产化设计

介绍了V2O3回转窑的国产化设计概况,简述了回转窑的特点及使用效果.