锂土改性水泥-水玻璃浆液的试验

Test of Li-bentonite Modified Cement-water Glass Grout

锂基膨润土(简称锂土)具有吸水能力强、吸附能力好、悬浮性能高等优点,有望弥补水泥-水玻璃(cement-sodium silicate,CS)浆液易离析、凝胶时间调节精度有限等缺陷。为查明锂土对CS浆液性能的影响,以质量比为0、5%、10%、15%、20%、25%和30%的锂土替代CS浆液中的水泥,考察了锂土对CS浆液的表观黏度、析水率、凝胶时间、早期抗压强度和水化产物的影响,得到了最优配合比。试验结果表明,锂土增加了浆液的表观黏度,有效降低了CS浆液的析水率,提高了浆液稳定性;在锂土掺量为10%以内时,可以缩短浆液的凝胶时间,而在锂土掺加20%左右时,可以提高浆液的早期强度。可见锂土能有效弥补CS浆液的缺陷。X射线衍射结果表明,锂土未改变CS浆液的水化产物类型。

Lithium-based bentonite(referred to as Li-bentonite)has the advantages of strong water absorption capacity,good adsorption capacity,and high suspension performance.It is expected to make up for the defects of cement-sodium silicate(CS)slurry,which has the disadvantage of being easy to segregate and has limited accuracy in setting time adjustment.In order to find out the effects of Li-bentonite on the properties of CS slurry,the mass ratio of 0,5%,10%,15%,20%,25%and 30%Li-bentonite was used to replace part of cement in CS slurry.The effects of Li-bentonite on the apparent viscosity,bleeding,setting time,early compressive strength and hydration products of CS grout were investigated.The mixing ratio of grouts was analyzed,and the optimal mixing ratio was obtained.The experimental results show that the Li-bentonite increases the apparent viscosity,effectively reduces the bleeding and improves the stability of slurry.The 0~10%of Li-bentonite shortens the setting time and 20%of Li-bentonite improves the early strength of the hardened slurry.In addition,it is found that the defects of CS slurry can be effectively compensated by Li-bentonite.X-ray diffraction test shows that no new minerals are formed in the CS grout with the addition of Li-bentonite.