本研究使用皂土和普通波特蘭水泥配合成各六種配比, 再以四種攪拌葉片(2.5~
lOcm) 、三種攪拌速率(1200~2400rpm)與水進行拌合,研究其黏度或浮水與時間的關
係,少數配比並以爐石粉取代部份水泥以觀察爐石粉對黏度及浮水的影響。研究結果
顯示:
(1)黏滯性:皂士或水泥的含量愈高,其黏度愈高:以皂土含量由4% 增至6% 為例,
在300分鐘前其黏度可提高3 . 3 倍以上:而水泥含量由16%增至20%的結果顯示,其
黏度亦可增加1. 3 倍以上。而攪拌速率的增加和葉片的增大均有助於黏度的發展,但需
配合整體的攪拌能量來看待,在葉片5cm 以上或攪拌速率1800rpm 以上更能發揮均勻
攪拌的效果。
(2) 浮水量:皂土含量提高對於抑制浮水產生的效果非常明顯,實驗結果顯示: 皂土含
量6% 的累積浮水量僅為4% 的0.34 倍; 而水泥含量的增加在攪拌能量足夠時卻會使
浮水增多,所以不具改善效果。另攪拌速率提高和葉片增大對於改善浮水則具有其正
面的意義,所有配比的累積浮水量約在0. 6~4.12% 之間。 Bentonite slurry mixed with cement makes a self-hardening slurry. The slurry is
utilized in the cut-off wall and diaphragm wall constructions. In this study, six different
slurries were made from different proportions of bentonite and ordinary Portland cement.The slurries are then made with four different propeller sizes (ranges from 2.S ........ 10 cm),
three mixing speeds(l200,1800,and 2400 rpm). Researches are focus on the viscosity and
bleeding water changes as a function of time of solidified slurries. Results from this study
shows:
(1) Viscosity of slurries increase with the amount of bentonite content and cement content.
Increase the mixing speed or the size of a propeller may result in larger viscosities. Better
homogenerity of slurries are often obtained from the propeller size larger than Scm or at
mixing speeds higher than 1800rpm.
(2) Increase the bentonite content may decrease the amount of bleeding water. Test results
show that amount of the bleeding water at 6% bentonite is about 34% of bleeding water at
4% bentonite. Increase the cement content results an increase of bleeding water when the
mixing energy is sufficient. Increase the mixing speed and the size of propeller may improve
the bleeding water condition. The bleeding ratio of all the mixtures are about 0.6 ......... 4.1 %.
關聯:
中華民國第二屆結構工程研討會暨國科會工程處結構工程專題研究成果研討會論文集(一)=Proceedings of the second National Conference on Structural Engineering,頁31-40