Effect of Chemical Composition of Fine Aggregate on the Frictional Behavior of Concrete–Soil Interface under Sulfuric Acid Environment

Jie Xiao,Bin Lei,Yikang Murong,Lei Wang,Haibo Jiang,Wenjun Qu,Zhenming Xu,Lijing Chu

doi:10.3390/fractalfract6010022

Abstract

Through direct shear tests, this paper aimed to research the effect of fine marble aggregate on the shear strength and fractal dimension of the interface between soil and concrete corroded by sulfuric acid. More realistic concrete rough surfaces than the artificially roughened surfaces were formed by immersing four concrete plates in plastic buckets filled with sulfuric acid for different periods of time. The sand was adopted to imitate the soil. 3D laser scanner was employed to obtain the digital shapes of concrete plates subjected to sulfuric acid, and the rough surfaces were evaluated by fractal dimension. Large direct shear experiments were performed to obtain the curves of the interface shear stress and shear displacement between sand and corroded concrete plate. The method of data fitting was adopted to calculate the parameters of shear strength (i.e., friction angle and the cohesive) and the parameters of the Clough–Duncan hyperbolic model. The results indicated that as the corrosion days increased, the surface of the concrete plate became rougher, the surface fractal dimensions of the concrete corroded by sulfuric acid became bigger, and the interface friction angle became greater. The friction angle of the interface and the fractal dimensions of the surface of the concrete plate containing crushed gravel and marble sand were smaller than that of the concrete plate containing crushed gravel and river sand.

Highlights

Introduction published maps and institutional affilThe research on the shear performance of interface between soil and structure has long received significant attention due to its common existence in geotechnical engineering including soil–pile foundation interaction, soil–retaining wall contact, soil–tunnel contact, and so on [1,2,3]
Photos of concrete plates soaked in the sulfuric acid for four predetermined durations Photos of concrete plates soaked in the sulfuric acid for four predetermined durations
The steps to obtain the fractal dimension of concrete plate surface under the sulfuric acid environment were the same as in reference [74], from which the detailed procedures could be obtained

Summary

Introduction

Introduction published maps and institutional affilThe research on the shear performance of interface between soil and structure has long received significant attention due to its common existence in geotechnical engineering including soil–pile foundation interaction, soil–retaining wall contact, soil–tunnel contact, and so on [1,2,3]. The shear performance of interface between soil and structure could be researched by performing in situ experiments and reduced model in the laboratory. The reduced model experiments between soil–structure interface, including direct shear experiments, simple shear experiments, and ring shear experiments [4,5,6,7,8,9,10,11,12,13,14,15], have the advantages of repeatability and parameter controllability. Since the direct shear test method was simple and the results were reasonable accurate, the direct shear test was usually selected to study the performance of the interfaces between soil and structure [16,17,18,19,20]. Previous studies have indicated that the shear strength of the soil–structure interface was influenced by the roughness of the structure interface, normal stress, water content of the soil, soil type, relative iations.

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Conclusion