Research on Damage and Deterioration of Fiber Concrete under Acid Rain Environment Based on GM(1,1)-Markov.

Jianqiao Yu,Feifei Zhu,Xinke Wang,Hongxia Qiao

doi:10.3390/ma14216326

Abstract

With steel fiber and basalt fiber volume dosing serving as variation parameters, a total of 200 d cycles of acid rain corrosion cycle tests were conducted on fiber concrete in this study. We selected three durability evaluation parameters to assess the degree of damage deterioration on fiber concrete, used scanning electron microscopy, mercury intrusion porosimetry, and a dimensional microhardness meter to analyze the concrete micromorphology, and established a GM(1,1)-Markov model for life prediction of its durability. Results reveal that the acid rain environment is the most sensitive to the influence of the relative dynamic elastic modulus evaluation parameter, and concrete has specimens that show failure damage under this parameter evaluation. Incorporation of fibers can reduce the amount of corrosion products inside the concrete, decrease the proportion of harmful pores, optimize the mean pore-size, and significantly improve the resistance to acid rain attack. Concrete with 2% steel fiber and 0.1% basalt fiber by volume has the least change in durability damage, and the predicted service life by GM(1,1)-Markov model is 322 d.

Highlights

In recent years, with the dramatic increase in emissions of nitrogen oxides and sulfides, acid rain pollution has become one of the important environmental issues in the world today, and it shows a continuous expanding trend of the affected area
Research reports indicate that over 100 billion yuan of annual losses in China is caused by acid rain problems, with the largest proportion of economic losses done by acid rain corrosion of construction materials such as concrete [1]
Shi et al [5] studied the mechanism of acid rain corrosion resistance of concrete with added mineral admixtures through X-ray diffraction, scanning electron microscopy, and energy spectrometry tests, and the results showed that polypropylene fiber fly ash expanded concrete had the best acid rain corrosion resistance

Summary

Introduction

With the dramatic increase in emissions of nitrogen oxides and sulfides, acid rain pollution has become one of the important environmental issues in the world today, and it shows a continuous expanding trend of the affected area. The microscopic morphology, pore structure, and mechanical properties of the interfacial transition zone (ITZ) of the corroded fiber concrete were characterized and analyzed by SEM, mercury intrusion porosimetry (MIP), microhardness (MH), and Materials 2021, 14, 6326 other microscopic tests, so as to establish a dynamic analysis model GM(1,1)-Markov for the life prediction of durability indexes considering the influence of acid rain damage, with a view to provide theoretical support for the assessment of durability performance of fiber concrete under an acid rain environment. This is to provide theoretical support for the durability assessment of fiber concrete in an acid rain environment

Materials and Mixture Proportions

Experimental Methods

Testing Procedure

Evaluation Parameters of Compressive Strength

Analysis of Prediction Result