Fractal Dimension of Basalt Fiber Reinforced Concrete (BFRC) and Its Correlations to Pore Structure, Strength and Shrinkage

In this study, we focused on exploring the correlations between the pore surface fractal dimensions and the pore structure parameters, strength and shrinkage properties of basalt fiber-reinforced concrete (BFRC). The pore structure of BFRCs with various fiber contents and fiber lengths was investiga...

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Main Authors: Yue Li, Aiqin Shen, Hua Wu
Format: Article
Language:English
Published: MDPI AG 2020-07-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/13/14/3238
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author Yue Li
Aiqin Shen
Hua Wu
author_facet Yue Li
Aiqin Shen
Hua Wu
author_sort Yue Li
collection DOAJ
description In this study, we focused on exploring the correlations between the pore surface fractal dimensions and the pore structure parameters, strength and shrinkage properties of basalt fiber-reinforced concrete (BFRC). The pore structure of BFRCs with various fiber contents and fiber lengths was investigated using mercury intrusion porosimetry (MIP) measurements. Through Zhang’s model, the fractal characteristics of BFRCs in the whole pore size range and in different pore size ranges were calculated from the MIP test data. The results showed that the addition of BF increased the total porosity, total pore volume and pore area but decreased the average pore diameter, indicating that BFs refined the pore structure of the concrete. BFRC presented obvious fractal characteristics in the entire pore-size range and individual pore-size ranges; generally, the fractal dimension increased with increasing fiber content. Moreover, correlation analysis suggested that the fractal dimension of BFRC in the whole pore-size range (FD) was closely related to the fractal dimension in the macropore region (D<sub>m</sub>) and average pore diameter (APD). The influence of pore structure factors on mechanical strength and shrinkage was studied by grey correlation theory, and the results showed that D<sub>m</sub> showed positive correlations with strength and fracture energy, with increasing D<sub>m</sub> tending to strengthen and toughen the concrete. An increase in fiber content and length was detrimental to reducing the drying shrinkage strain. In the transition pore region, the fractal dimension (D<sub>t</sub>) at diameters ranging from 20 to 50 nm and shrinkage strain exhibited a highly linear relation. These results merit careful consideration in macro-property evaluation by using the pore surface fractal dimension in a specific region instead of the whole region. Finally, grey target theory was applied to evaluate the rank of the mechanical strength and shrinkage of concrete, and the results showed that the overall properties of concrete with a BF length of 18 mm and a BF content of 0.06% ranked the best.
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spelling doaj.art-3889776dcba34cdfbc3d1b847cb2328e2023-11-20T07:25:02ZengMDPI AGMaterials1996-19442020-07-011314323810.3390/ma13143238Fractal Dimension of Basalt Fiber Reinforced Concrete (BFRC) and Its Correlations to Pore Structure, Strength and ShrinkageYue Li0Aiqin Shen1Hua Wu2Key Laboratory for Special Region Highway Engineering of Ministry of Education, Chang’an University, Xi’an 710064, ChinaKey Laboratory for Special Region Highway Engineering of Ministry of Education, Chang’an University, Xi’an 710064, ChinaKey Laboratory for Special Region Highway Engineering of Ministry of Education, Chang’an University, Xi’an 710064, ChinaIn this study, we focused on exploring the correlations between the pore surface fractal dimensions and the pore structure parameters, strength and shrinkage properties of basalt fiber-reinforced concrete (BFRC). The pore structure of BFRCs with various fiber contents and fiber lengths was investigated using mercury intrusion porosimetry (MIP) measurements. Through Zhang’s model, the fractal characteristics of BFRCs in the whole pore size range and in different pore size ranges were calculated from the MIP test data. The results showed that the addition of BF increased the total porosity, total pore volume and pore area but decreased the average pore diameter, indicating that BFs refined the pore structure of the concrete. BFRC presented obvious fractal characteristics in the entire pore-size range and individual pore-size ranges; generally, the fractal dimension increased with increasing fiber content. Moreover, correlation analysis suggested that the fractal dimension of BFRC in the whole pore-size range (FD) was closely related to the fractal dimension in the macropore region (D<sub>m</sub>) and average pore diameter (APD). The influence of pore structure factors on mechanical strength and shrinkage was studied by grey correlation theory, and the results showed that D<sub>m</sub> showed positive correlations with strength and fracture energy, with increasing D<sub>m</sub> tending to strengthen and toughen the concrete. An increase in fiber content and length was detrimental to reducing the drying shrinkage strain. In the transition pore region, the fractal dimension (D<sub>t</sub>) at diameters ranging from 20 to 50 nm and shrinkage strain exhibited a highly linear relation. These results merit careful consideration in macro-property evaluation by using the pore surface fractal dimension in a specific region instead of the whole region. Finally, grey target theory was applied to evaluate the rank of the mechanical strength and shrinkage of concrete, and the results showed that the overall properties of concrete with a BF length of 18 mm and a BF content of 0.06% ranked the best.https://www.mdpi.com/1996-1944/13/14/3238basalt fiberfractal dimensionstrengthcorrelationgrey correlation theory
spellingShingle Yue Li
Aiqin Shen
Hua Wu
Fractal Dimension of Basalt Fiber Reinforced Concrete (BFRC) and Its Correlations to Pore Structure, Strength and Shrinkage
Materials
basalt fiber
fractal dimension
strength
correlation
grey correlation theory
title Fractal Dimension of Basalt Fiber Reinforced Concrete (BFRC) and Its Correlations to Pore Structure, Strength and Shrinkage
title_full Fractal Dimension of Basalt Fiber Reinforced Concrete (BFRC) and Its Correlations to Pore Structure, Strength and Shrinkage
title_fullStr Fractal Dimension of Basalt Fiber Reinforced Concrete (BFRC) and Its Correlations to Pore Structure, Strength and Shrinkage
title_full_unstemmed Fractal Dimension of Basalt Fiber Reinforced Concrete (BFRC) and Its Correlations to Pore Structure, Strength and Shrinkage
title_short Fractal Dimension of Basalt Fiber Reinforced Concrete (BFRC) and Its Correlations to Pore Structure, Strength and Shrinkage
title_sort fractal dimension of basalt fiber reinforced concrete bfrc and its correlations to pore structure strength and shrinkage
topic basalt fiber
fractal dimension
strength
correlation
grey correlation theory
url https://www.mdpi.com/1996-1944/13/14/3238
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AT aiqinshen fractaldimensionofbasaltfiberreinforcedconcretebfrcanditscorrelationstoporestructurestrengthandshrinkage
AT huawu fractaldimensionofbasaltfiberreinforcedconcretebfrcanditscorrelationstoporestructurestrengthandshrinkage