Influence of Chemical Corrosion on Pore Structure and Mechanical Properties of Sandstone

Yun Lin,Jian Zhang,Rugao Gao,Jielin Li,Keping Zhou

doi:10.1155/2019/7320536

Yun Lin, Jian Zhang + Show 3 more

Open Access

https://doi.org/10.1155/2019/7320536

Copy DOI

Abstract

Chemical corrosion plays a significant role in affecting the properties of rock materials. To understand the effects of chemical corrosion on the pore structure and mechanical properties of sandstones, porosity, T2 spectrum distribution, and NMR images of sandstone specimens were measured after every 10 days of immersion in chemical solutions using the nuclear magnetic resonance (NMR) technique. Static uniaxial compressive tests and dynamic compressive tests were conducted using a conventional servo-controlled testing machine and a split Hopkinson pressure bar (SHPB) system for specimens treated with chemical corrosion. The test results showed that after being treated with chemical corrosion, the porosity of a specimen increased, the T2 spectrum distribution would successively shift towards the right, and the distribution of pores tended to become more irregular. Additionally, all of the compressive strength and elastic modulus of sandstone treated with chemical corrosion under static and dynamic loads decreased, and the peak strain increased. The effect order of a chemical solution on the pore structure and mechanical properties of sandstone was H2SO4>NaOH>distilled water, which would be related to the different mechanisms of a water-rock reaction. According to the experimental results, the correlations between the mechanical properties and porosity were established. The results can serve as a reference for research in related fields.

Highlights

Rock, as a natural geological body, has a pore structure that is closely related to the surrounding environment [1]
The Nuclear magnetic resonance (NMR) technique can vividly reflect the distribution of pores inside rocks
The alterations on the pore structure and mechanical properties of sandstone caused by chemical corrosion have been experimentally investigated

Summary

Introduction

As a natural geological body, has a pore structure that is closely related to the surrounding environment [1]. It is helpful to analyze the corrosion mechanism of chemical solutions and the degradation characteristics of rock mechanical properties to develop the study of the evolution of rock pore structure under the condition of chemical corrosion. Many advanced techniques, such as CT scanning [11,12,13,14], SEM [15,16,17,18], and P-wave velocity [1, 19,20,21], have been applied to the measurement of pore structures of rocks. The NMR technique is used to investigate the pore structure of rocks in this work

Methods

Results

Conclusion