Dynamic stress and microanalyses of the cement-soil modified by nano-SiO2 in the seawater corrosive environment

Abstract

In order to study the coupling effect of nano-SiO2 modified cement soil against dynamic load and seawater corrosion, dynamic stress parameters, NMR curves and SEM diagrams under different sea salt solution concentrations and times are obtained through the dynamic triaxial, scanning electron microscope and nuclear magnetic resonance tests to explore the effects of sea salt solution concentrations and corrosion days on the cement soil before and after improvement. The test results show that the internal pores of the improved soil are reduced, the cementation between the soil particles is improved, and the soil's ability to resist the coupling action of dynamic load and seawater corrosion is enhanced. Under the clear water environment, the dynamic strength of the improved cement soil after curing for 7, 14 and 28 days is increased by 4.8%, 6.6% and 7.3%, respectively. After sea water corrosion, the internal structure of soil is damaged, soil particles become loose and pores increased, and the dynamic strength of the cement soil decreases significantly. After 28 days of corrosion, the dynamic strength of the nano cement soil is increased by 9.4%, 7.3%, 6.6% and 6.3%, respectively, compared with the ordinary cement soil under the environment of clean water, double and triple seawater concentration solution.

Keywords

• nano-sio2
• cement soil
• dynamic triaxial
• dynamic strength
• corrosive environment