矿渣基地聚合物固化土强度及微观特征试验研究

Experimental Study on Strength and Microstructure of Ground Granulated Blast Furnace-Slag Based Geopolymer-Stabilized Soil

我国每年产生大量的碱渣(SR)、矿渣(GGBS)等工业固体废弃物,对其进行再次利用具有必要性.有别于水泥等传统固化剂,提出一种新型软土固化剂,该固化剂以矿渣为原料,以碱渣和石灰为复合碱激发剂.通过开展室内无侧限抗压强度(UCS)试验及低场核磁共振(LF-NMR)试验,研究其加固软土的效果及微观结构特征.试验结果表明,矿渣基地聚合物固化土强度主要影响因素为矿渣掺量,次要影响因素为复合碱激发剂掺量;当石灰、碱渣、矿渣质量比为1∶1∶2时,矿渣基地聚合物固化土的强度达到最大,为同掺量水泥(12%)的1.4倍.核磁共振试验发现,矿渣基地聚合物固化土的小孔和中孔约占95%,孔径分布范围主要为1.6~6.3μm.

A large amount of industry by-products such as soda residue(SR)and ground granulated blast furnace slag(GGBS)were produced every year,and it is necessary to reuse them.In this article,a kind of stabilization,instead of cement,with lime and soda residue as compound alkali activator and ground granulated blast furnace slag as raw material was proposed for soil stabilization.The unconfined compressive strength(UCS)test and low-field nuclear magnetic resonance(LF-NMR)test were used to analyze the strength characteristics and microstructure characteristics.The results showed that the main influencing factor of the strength of the ground granulated blast furnace-slag based geopolymer-stabilized soil was the slag content,and the secondary influencing factor was the compound alkali activator content.When the ratio of lime content to soda residue content to slag content was 1 to 1 to 2,the strength of the geopolymer-stabilized soil was 1.4 times that of the cement-stabilized soil.The nuclear magnetic resonance test found that the mini-pores and the meso-pores of geopolymer-stabilized soil accounted for about 95%,and the pore size distribution range was mainly 1.6-6.3μm.