Scientific Research on Quality Improvement of Concrete by Utilization of Pulverized Coal Ash

在2005年至2007年的三年内进行了(1)~(7)项研究。(1)关于粉煤灰的参考研究：对国内外的文章、报告、标准进行文献调查。(2)粉煤灰的事实调查：调查了日本各地粉煤灰的实际情况，FA I类为25%，FA II类为62%，FA III类为0%，FA IV类为25%，FA II类的平均细度约为3800 cm^2/g。(3)大量掺加粉煤灰对混凝土强度性能的影响试验研究：进行了大量掺加粉煤灰对混凝土强度的影响、模板强度发展与保持期、过量掺加对混凝土强度的影响三个系列试验。抗压强度随着替代率的增加而下降，但在相同W/C下，当91天龄期更换15%时，抗压强度与其他水泥相当，并给出了强度修正T和模板保留期限的计算图，…更多，并显示了过度掺合的有害影响程度。(4)粉煤灰广泛使用对混凝土碳化的试验研究：进行了三个系列的试验，阐明了混凝土的干缩减小、碳化增大、抗冻融性能降低等现象。(5)粉煤灰混凝土质量改善效果的试验研究：通过四个系列的干燥还原试验，阐明了细度、含水量对干燥收缩率、质量改善效果、浇筑固结新混凝土粘结强度的影响。(6)粉煤灰混凝土高温劣化试验研究：澄清了20 ~ 300℃长期高温加热后混凝土的抗压强度和杨氏模量均低于4种水泥。(7)粉煤灰对碱-硅反应抑制作用的实验研究：ⅰ类、ⅱ类、ⅲ类对正常反应性骨料的抑制作用，ⅱ类替代率为15%时均有抑制作用。少

Following (1)~(7) studies was performed in three years from 2005 to 2007.(1) Reference study about pulverized coal ash:Documents investigation of internal and external article, report and standards was performed.(2) Fact-findings about pulverized coal ash:The actual situation of the coal ash all over Japan was investigated, and FA class I was 25%, FA class II was 62%, FA class III was 0% and FA class IV was 25%, and the average fineness of FA class II was clarified approximately 3,800 cm^2/g.(3) Experimental study about strength property of concrete with extensive use of pulverized coal ash:Three series of experiment was made, such as influence of extensive use, strength development and retaining period of formwork, and excessive addition.Compressive strength deteriorates with the replacement ratio, but becomes equivalent with other cement when replacement of 15% in age of 91 days with same W/C and suggested the calculation chart of strength revision T and retaining period of formwork, … More and showed the degree of harmful influence by excessive mix.(4) Experimental study about carbonation of concrete with extensive use of pulverized coal ash:Three series of experiment was made, and clarified the phenomena such as reduce of drying shrinkage, increase of carbonation and decrease of freeze-thaw resistance.(5) Experimental study about quality improvement effect of concrete using pulverized coal ash:Effect of fineness, effect of water content to drying shrinkage, quality improvement effect, and bond strength of placing on consolidated fresh concrete by these four series of experiment reduce of drying was clarified.(6) Experimental study about high temperature deterioration of concrete using pulverized coal ash:The compressive strength and young's module reduction of after long-term high temperature heating from 20-300 degrees Celsius was lower than four types of cement were clarified.(7) Experimental study about inhibitive effect of Alkali-Silica Reaction by pulverized coal ash:The inhibitive effect at replacement rate 15% of class II in inhibitive effect of class I, class II and class III to normal reactive aggregates was showed. Less