Engineering Properties Experimental Studies Of Lightweight Cement Stabilized Soil And Lightweght Geopolymer Stabilized Soil

Foamed lightweght soil, a new type of filling material, is mixing by in situ soil,curing agent and foam. It has a lot of advantages including lighweight,great self-standing,short construction period,waste rectcling and environment protection.In Japan, it’s widely used in backfill engineering,embankment and port construction and many other aspects. In this paper, clay, foaming agent, cement and geopolymer are used to produce foamed lightweight soil. A series of laboratory tests are conducted to evaluate its physical and mechanical properties, water stability, water absorption, water permeability, wetting-drying and sodium sulfate soaking durability. The main works can be summarized as follow:(1)By water absorption and permeability tests, water absorption and permeability of lightweight cement stabilized soil and lightweight geopolymer stabilized soil has been investigated comparatively. The results showed that ightweight geopolymer stabilized soil has higher water absorption and greater permeability than lightweight cement stabilized soil.(2)By unconfined compressin strength tests, the UCS of lightweight cement stabilized soil and lightweight geopolymer stabilized soil has been investigated comparatively. The results show that under the same condition, the UCS of lightweight geopolymer stabilized soil is twice as that of lightweight cement stabilized soil; the main factor affecting the UCS of lightweight geopolymer stabilized soil and lightweight geopolymer stabilized soil is Vv/Vc (pore volume and curing agent volume ratio). The empirical formula qu= A/(Vv/Vc)B is obtained from the datas to facilitate engineering applications.(3)By water stability tests, the water stability of lightweight cement stabilized soil and lightweight geopolymer stabilized soil has been investigated comparatively. The results showed that lightweight cement stabilized soil and lightweight geopolymer stabilized soil have good water stability(4) By one-dimensional consolidation test, the compression behavior of lightweight cement stabilized soil and lightweight geopolymer stabilized soil has been investigated comparatively. The results showed that the yield stress decreases with Vv/Vc increases, after yielding compression index increases with Vv/Vc increases.(5) By wetting-drying test and sulfate attack test, the wetting-drying durability and sodium sulfate soaking durability of lightweight cement stabilized soil and lightweight geopolymer stabilized soil has been investigated comparatively. The results showed that. Lightweight cement stabilized soil has better wetting-drying durability and weaker sodium sulfate soaking durability than lightweight geopolymer stabilized soil.(6) By MIP test, the pore distribution of lightweight cement stabilized soil and lightweight geopolymer stabilized soil was studied comparatively. By SEM test, the morphology of hydration products of lightweight cement stabilized soil and lightweight geopolymer stabilized soil was studied comparatively. By TGA test, the quantity of hydration products was studied comparatively.