摘要
粗制人工砂的级配一般很不稳定，但坑口水电站碾压混凝土坝的实践表明，用这种人工砂配制的碾压混凝土，各项充填指标都变化很小，且施工性能和各项物理力学指标均优于级配相对稳定的天然砂碾压混凝土。在坑口碾压混凝土坝的施工中，引入了细砂（ｄ＜２．５ｍｍ）率这一指标，还把人工砂粉粒（ｄ＜０．１６ｍｍ）计入灰浆计算灰浆在细砂砂浆中所占比例的比例系数Ｋｐ６。根据坑口工程的经验，砂的种类不同，细砂率比较稳定；Ｋｐ６能较好地反映灰浆数量的多少和混凝土的施工性能。因此，采用细砂率作为砂率的控制指标，采用Ｋｐ６表示碾压混凝土的灰浆含量。
The conventional grading of roughly refined sand is unstable.But,the Kengkou dam's practice showed that the RCC made of such roughly refined sand has relatively stable placement indexes,and, its workability and various physical/mechanical properties are superior to those of the RCC made of natural sand with relatively stable grading.In Kengkou RCC dam construction a differential grading concept with two newly suggested indexes was introduced.An index is the fine sand-aggregate ratio,with fine sand's size less than 2.5 mm.Another index,Kp6,is the proportional coefficient of the cement paste,a proportion of cement and finest sand particles(d<0.16 mm) to the fine sand-cement mortar.The experience at the Kengkou dam construction indicated that for different kinds of refined sand,the fine sand-aggregate ratio is quite stable;and the Kp6 can properly reflect both the quantity of the cement paste and the concrete workability.Thus,the fine sand-aggregate ratio was selected as an useful index for grading control,and Kp6,for expressing to a certain extent the cement paste content of RCC.
出处
《人民长江》
北大核心
1996年第5期13-16,共4页
Yangtze River
关键词
碾压混凝土
水电站
人工砂
颗粒
级配
Roll compacted concrete
Crushed sand
Grain gradation
Rolled concrete dam
Fujian
