# The Effect of Recycled Sand on the Tensile Properties of Engineered Cementitious Composites

^{1}

^{2}

^{*}

## Abstract

**:**

## 1. Introduction

_{2}emissions [2,3]. Meanwhile, construction and demolition (C&D) waste, produced by demolishing abandoned structures, takes a relatively large proportion of the total amount of waste in recent years. The most common disposal method of C&D waste in some developing countries is landfilled, inevitably resulting in water, atmospheric and soil contamination as well as landfill saturation [4,5]. Using C&D waste to produce recycled construction materials, e.g., recycled aggregate, is a reasonable method to minimize the negative influence on end-of-life structures, as well as to decrease the demand for extraction of resources. In processing C&D waste, recycled sand (RS) accounts for about 20% of the gross amount of recycled aggregate [6,7,8,9]. Despite RS being abundant in C&D waste, the understanding of concrete incorporated with RS is limited. In recent years, many investigators have attempted to investigate the influence of RS replacement on the mechanical property of concrete. Khatib [10] conducted a series of experiments to investigate the replacement ratios of fine recycled aggregate (FRA) on the mechanical property, which led to 15% and 30% compressive loss at replacement ratios of 25% and 100%, respectively. Evangelista et al. [11] stated that there were no significant reductions with percentages of substitution of RS up to 30%. Khoshkenari et al. [12] discovered that FRA decreases the splitting tensile and compressive strength of concrete, which can be compensated by incorporating fine natural aggregate of 0–2 mm size. Pereira et al. [13] demonstrated that the mechanical properties of the concrete prepared from RS incorporated with superplasticizer exceeded that of normal concrete in the control group. Huang et al. [14] introduced two kinds of RS with different crashing processes and fine moduli into concrete. The test results indicated that RS with a small fine modulus and low water absorption rate tends to help maintain the mechanical strength of concrete.

- Achieve a better understanding of recycled sand applicable to ECC. X-ray fluorescence (XRF), scanning electron microscope (SEM) and particle size analysis were used to obtain chemical compositions, physical properties, and fineness of RS.
- Investigate the influence of RS replacement on the basic mechanical properties of ECC.
- Find the influence of RS replacement on the meso-scale and micro-scale properties of RS-ECC and explore the connection between the RS-ECCs tensile strain capacity and meso-scale property.

## 2. Materials and Experimental Program

#### 2.1. Materials and Mix Proportions

#### 2.2. Preparation of Specimens

#### 2.3. Mechanical Properties Tests

## 3. Results and Discussions

#### 3.1. Tensile Behavior

#### 3.2. Compressive and Bending Properties

#### 3.3. Discussion on the Effect of RS Replacement at the Meso-Scale

_{b}′ is computed from the hatched area, as shown in Figure 12. J

_{b}′ reflects the energy consumed when fibers are pulled out from the matrix. The CMOD curves of the four mixtures are shown in Figure 13. The different colored lines in Figure 13 demonstrate the different specimens in each groups. Table 8 lists the key parameters of the test.

_{OC}suffered almost no loss when NS was replaced by RS (in Figure 6), which indicates that RS has little adverse effect on the bond-slip capacity between the fiber and matrix.

_{Q}and the fracture energy J

_{tip}of the three-point bending tests are calculated by the following equations [34].

_{Q}and J

_{tip}are listed in Table 9. The average fracture toughness of the RS-plain-20 grid and RS-plain-12 grid was 0.393 and 0.363 MPa·m

^{1/2}, obviously lower than that of the NS-plain-20 grid and NS-plain-12 grid, which was 0.514 and 0.463 MPa·m

^{1/2}, respectively. In comparison to NS, RS has the ability to reduce the matrix fracture toughness. When focusing on the effect on fracture energy brought by fineness of the aggregate, it is well known that finer aggregate leads to smaller fracture energy [35]. Consistently, specimens of the 20 grid had smaller fracture energy, as compared to those of the 12 grid.

_{b}′ and the matrix fracture energy J

_{tip}. To be more specific, a relatively lower ratio of J

_{tip}/J

_{b}′ tends to easily lead to crack generation and propagation, which finally facilitate the tensile capacity of the composite. As can be seen in Table 10, the replacement of NS by RS efficiently reduces the fracture toughness of the matrix and keeps the fiber bridging capacity J

_{b}′ nearly constant. In addition, it can be concluded that the fracture toughness of the matrix could be reduced by coarse sand (12 grid), not only for RS but also for NS. As a result, the PSH index J

_{b}′/J

_{tip}increases by 46% and 70% after the replacement of NS by RS of the 20 and 12 grids, respectively. There is a similar trend between the J

_{b}′/J

_{tip}and the tensile ductility. The impact of RS replacement is reflected in the enhanced pseudo-strain-hardening (PSH) index J

_{b}′/J

_{tip}, therefore explaining the positive influence of RS on the tensile strain capacity of ECC.

^{2}, as shown in Figure 15, which all together form a numerical fracture surface whose area can be easily calculated. Figure 16 shows a contour map of the RS-ECCs fracture surface cut by its base plane. The degree of warmth of color reflects the relative position and distance of a certain datum point to the base plane. As shown in Figure 17, most enhancement rates of the fracture area range from 3 to 7%, which are considered of little influence on the fracture energy at such a large scale. Therefore, the first explanation, i.e., a different pattern of crack propagation, is ruled out. The only explanation for the decrease in fracture toughness brought by RS replacement should be the weakened interface between the new cement binder and RS, which is consistent with the results given by Xiao et al. [38].

## 4. Conclusions

- (1)
- The ECC with RS showed excellent tensile ductility with a tensile strain of 7%, which is greater than that of the ECC with NS. Furthermore, the incorporation of RS into ECC maintained the same tensile strength as that of NS-ECC.
- (2)
- The compressive and flexural strengths of ECC were over 50 and 20 MPa. The addition of RS did not cause a significant loss of compressive and flexural strength, compared with that of ECC with NS.
- (3)
- The addition of RS decreased the matrix toughness and kept the fiber-bridging capacity constant. The pseudo-strain-hardening (PSH) of RS-ECC showed the highest value, which could benefit tensile ductility. The main reason for this was that the old residual mortar around the RS increased the gap of elastic modulus between the sand and ITZ, which decreased the matrix toughness and improved the tensile ductility.

## Author Contributions

## Funding

## Conflicts of Interest

## References

- Xiao, J.Z.; Qiang, C.B.; Nanni, A.; Zhang, K.J. Use of sea-sand and seawater in concrete construction: Current status and future opportunities. Constr. Build. Mater.
**2017**, 155, 1101–1111. [Google Scholar] [CrossRef] - Reyes-sánchezi, J.A.; Tenza-Abril, A.J.; Verdu, F.; Perales, J.A.R. Predicting modulus of elasticity of recycled aggregate concrete using nonlinear mathematical models. Int. J. Comp. Meth. Exp. Meas.
**2018**, 6, 703–715. [Google Scholar] [CrossRef] [Green Version] - Monteiro, P.J.M.; Miller, S.A.; Horvath, A. Towards sustainable concrete. Nat. Mater.
**2017**, 16, 698. [Google Scholar] [CrossRef] [PubMed] - Bourguiba, A.; Ghorbel, E.; Cristofol, L.; Dhaoui, W. Effects of recycled sand on the properties and durability of polymer and cement based mortars. Constr. Build. Mater.
**2017**, 153, 44–54. [Google Scholar] [CrossRef] - Xiao, J.Z.; Ma, Z.M.; Ding, T. Reclamation chain of waste concrete: A case study of shanghai. Waste Manag.
**2015**, 48, 334–343. [Google Scholar] [CrossRef] [PubMed] - Rahal, K. Mechanical properties of concrete with recycled coarse aggregate. Build. Environ.
**2007**, 42, 407–415. [Google Scholar] [CrossRef] - Corinaldesi, V. Mechanical and elastic behavior of concretes made of recycled-concrete coarse aggregates. Constr. Build. Mater.
**2010**, 24, 1616–1620. [Google Scholar] [CrossRef] - Pedro, D.J.; de Brito, J.; Evangelista, L. Influence of the use of recycled concrete aggregates from different sources on structural concrete. Constr. Build. Mater.
**2014**, 71, 141–151. [Google Scholar] [CrossRef] - Ferro, G.A.; Spoto, C.; Tulliani, J.M.; Restuccia, L. Mortar made of recycled sand from C&D. Procedia Eng.
**2015**, 109, 240–247. [Google Scholar] - Khatib, J.M. Properties of concrete incorporating fine recycled aggregate. Cem. Concr. Res.
**2005**, 35, 763–769. [Google Scholar] [CrossRef] - Evangelista, L.; de Brito, J. Mechanical behaviour of concrete made with fine recycled concrete aggregates. Cem. Concr. Compos.
**2007**, 29, 397–401. [Google Scholar] [CrossRef] - Khoshkenari, A.G.; Shafigh, P.; Moghimi, M.; Mahmud, H.B. The role of 0–2 mm fine recycled concrete aggregate on the compressive and splitting tensile strengths of recycled concrete aggregate concrete. Mater. Des.
**2014**, 64, 345–354. [Google Scholar] [CrossRef] - Pereira, P.; Evangelista, L.; de Brito, J. The effect of superplasticisers on theworkability and compressive strength of concrete made with fine recycledconcrete aggregates. Constr. Build. Mater.
**2012**, 28, 722–729. [Google Scholar] [CrossRef] [Green Version] - Fan, C.; Huang, R.; Hwang, H.; Chao, S. Properties of concrete incorporating fine recycled aggregates from crushed concrete wastes. Constr. Build. Mater.
**2016**, 112, 708–715. [Google Scholar] [CrossRef] - Carro-López, D.; Gónzález-Fonteboa, F.; Martínez, A.; Gónzález, T.; de Brito, J.; Varela-Puga, F. Proportioning, microstructure and fresh properties of self-compacting concrete with recycled sand. Procedia Eng.
**2017**, 171, 645–657. [Google Scholar] [CrossRef] - Yu, K.; Mcgee, W.; Ng, T.Y.; Zhu, H.; Li, V.C. 3D-printable engineered cementitious composites (3DP-ECC): Fresh and hardened properties. Cem. Concr. Res.
**2021**, 143, 106388. [Google Scholar] [CrossRef] - Ye, J.; Cui, C.; Yu, J.; Yu, K.; Xiao, J. Fresh and anisotropic-mechanical properties of 3D printable ultra-high ductile concrete with crumb rubber. Compos. Part B Eng.
**2021**, 211, 108639. [Google Scholar] [CrossRef] - Liao, Q.; Su, Y.; Yu, J.; Yu, K. Torsional behavior of BFRP bars reinforced engineered cementitious composites beams without stirrup. Eng. Struct.
**2022**, 268, 114748. [Google Scholar] [CrossRef] - Liao, Q.; Su, Y.; Yu, J.; Yu, K. Compression-shear performance and failure criteria of seawater sea-sand engineered cementitious composites with polyethylene fibers. Constr. Build. Mater.
**2022**, 345, 128386. [Google Scholar] [CrossRef] - Li, V.C. Engineered cementitious composites-tailored composites through micromechanical modelling. In Fiber Reinforced Concrete: Present and the Future; Canadian Society for Civil Engineering: Montreal, QC, Canada, 1998; pp. 64–97. [Google Scholar]
- Cai, Z.; Liu, F.; Yu, J.; Yu, K.; Tian, L. Development of ultra-high ductility engineered cementitious composites as a novel and resilient fireproof coating. Constr. Build. Mater.
**2021**, 288, 123090. [Google Scholar] [CrossRef] - Sahmaran, M.; Li, M.; Li, V.C. Transport Properties of Engineered Cementitious Composites under Chloride Exposure. ACI Mater. J.
**2007**, 104, 303–310. [Google Scholar] - Qian, S.Z.; Li, V.C. Headed Anchor/Engineered Cementitious Composites (ECC) Pullout Behavior. J. Adv. Concr. Technol.
**2011**, 9, 339–351. [Google Scholar] [CrossRef] - Qian, S.Z.; Li, V.C.; Zhang, H.; Keoleian, G.A. Life cycle analysis of pavement overlays made with Engineered Cementitious Composites. Cem. Concr. Compos.
**2013**, 35, 78–88. [Google Scholar] [CrossRef] - Dong, Z.; Tan, H.; Yu, J.; Liu, F. A feasibility study on Engineered cementitious Composites mixed with coarse aggregate. Constr. Build. Mater.
**2022**, 350, 128587. [Google Scholar] [CrossRef] - Sahmaran, M.; Lachemi, M.; Li, V.C. Assessing the Durability of Engineered Cementitious Composites Under Freezing and Thawing Cycles. J. ASTM Int.
**2009**, 6, 102406–102419. [Google Scholar] - Kanda, T.; Li, V.C. New micromechanics design theory for pseudo strain hardening cementitious composite. ASCE J. Eng. Mech.
**1999**, 125, 373–381. [Google Scholar] [CrossRef] [Green Version] - Wang, S.; Li, V.C. Tailoring of pre-existing flaws in ECC matrix for saturated strain hardening. In Proceedings of the Fifth International Conference on Fracture Mechanics of Concrete and Concrete Structures, Vail, CO, USA, 12–16 April 2004; pp. 1005–1012. [Google Scholar]
- Zhang, Z.G.; Qian, S.Z.; Ma, H. Investigating mechanical properties and self-healing behavior of micro-cracked ECC with different volume of fly ash. Constr. Build. Mater.
**2014**, 52, 17–23. [Google Scholar] [CrossRef] - Zhang, Z.G.; Ma, H.; Qian, S.Z. Investigation on Properties of ECC Incorporating Crumb Rubber of Different Sizes. J. Adv. Concr. Technol.
**2015**, 13, 241–251. [Google Scholar] [CrossRef] [Green Version] - Zhang, Z.G.; Zhang, Q.; Qian, S.Z.; Li, V.C. Low E-Modulus Early Strength Engineered Cementitious Composites Material Development for Ultrathin Whitetopping Overlay. Transp. Res. Rec. J. Transp. Res. Board
**2015**, 2481, 41–47. [Google Scholar] [CrossRef] - Lepech, M.D.; Li, V.C. Application of ECC for bridge deck link slabs. Mater. Struct.
**2009**, 42, 1185–1195. [Google Scholar] [CrossRef] - Sahmaran, M.; Yücel, H.E.; Demirhan, S.; Arık, M.T.; Li, V.C. Combined Effect of Aggregate and Mineral Admixtures on Tensile Ductility of Engineered Cementitious Composites. ACI Mater. J.
**2009**, 109, 11. [Google Scholar] - Xu, S.; Reinhardt, H.W. Determination of double-K criterion for crack propagation in quasi-brittle fracture, Part II: Analytical evaluating and practical measuring methods for three-point bending notched beams. Int. J. Fract.
**1999**, 98, 151–177. [Google Scholar] [CrossRef] - Yang, Y.Z.; Yao, Y.; Zhu, Y. Effects of Gradation of Sand on the Mechanical Properties of Engineered Cementitious Composites. Adv. Mater. Res.
**2011**, 250, 374–378. [Google Scholar] [CrossRef] - Chen, B.; Li, J. Effect of aggregate on the fracture behavior of high strength concrete. Constr. Build. Mater.
**2004**, 18, 585–590. [Google Scholar] [CrossRef] - Li, Y.; Li, J.Q. Relationship between fracture area and tensile strength of cement matrix with supplementary cementitious materials. Constr. Build. Mater.
**2015**, 79, 223–228. [Google Scholar] [CrossRef] - Li, W.; Xiao, J.; Sun, Z.; Kawashima, S.; Shah, S.P. Interfacial transition zones in recycled aggregate concrete with different mixing approaches. Constr. Build. Mater.
**2012**, 35, 1045–1055. [Google Scholar] [CrossRef] [Green Version] - Ollivier, J.P.; Maso, J.C.; Bourdette, B. Interfacial transition zone in concrete. Adv. Cem. Based Mater.
**1995**, 2, 30–38. [Google Scholar] [CrossRef] - Bremner, T.W.; Holm, T.A. Elastic Compatibility and the Behavior of Concrete. J. Proc.
**1986**, 83, 244–250. [Google Scholar]

**Figure 12.**Typical σ-δ curve for strain-hardening composites. The hatched area represents complementary energy J

_{b}′. Shaded area represents matrix toughness J

_{tip}.

**Figure 13.**Single crack tensile test curve of ECC mixtures. (

**a**) RS-ECC-20 grid; (

**b**) RS-ECC-12 grid; (

**c**) NS-ECC-20 grid; (

**d**) NS-ECC-12 grid.

**Figure 18.**Microstructure characterization of NS-ECC and RS-ECC. (

**a**) RS-ECC-20 grid; (

**b**) NS-ECC-12 grid.

Mixture ID | PE Fiber (g) | Cement (g) | Fly Ash (g) | NS (g) | RS (g) | Water (g) | HRWR (g) |
---|---|---|---|---|---|---|---|

RS-ECC-20 grid | 20 | 628 | 754 | 0 | 502 | 387 | 1.8 |

RS-ECC-12 grid | 20 | 628 | 754 | 502 | 0 | 387 | 1.0 |

NS-ECC-20 grid | 20 | 628 | 754 | 0 | 502 | 387 | 1.8 |

NS-ECC-12 grid | 20 | 628 | 754 | 502 | 0 | 387 | 1.0 |

Ingredients | Fly Ash | Recycled Sand | |
---|---|---|---|

Chemical composition (%) | Na_{2}O | 0.58 | 0.86 |

MgO | 0.90 | 2.26 | |

Al_{2}O_{3} | 23.9 | 12.0 | |

SiO_{2} | 51.7 | 47.9 | |

P_{2}O_{5} | 0.40 | 0.29 | |

SO_{3} | 0.91 | 1.41 | |

K_{2}O | 1.40 | 2.33 | |

CaO | 7.65 | 18.7 | |

TiO_{2} | 1.19 | 0.82 | |

MnO | 0.07 | 0.10 | |

Fe_{2}O_{3} | 5.22 | 6.53 | |

Cl^{−} | / | 0.06 | |

Cr_{2}O_{3} | / | 0.02 | |

NiO | / | 0.01 | |

CuO | / | 0.01 | |

ZnO | / | 0.02 | |

SrO | / | 0.03 | |

ZrO_{2} | / | 0.02 |

Diameter (μm) | Fiber Aspect Ratio | Nominal Strength (GPa) | Modulus (GPa) | Rupture Elongation (%) | Density (g/cm ^{3}) | Melting Point (°C) |
---|---|---|---|---|---|---|

25 | 720 | 2.9 | 116 | 2.42 | 0.97 | 150 |

Mixture ID | RS-ECC-12 Grid | NS-ECC-12 Grid | RS-ECC-20 Grid | NS-ECC-20 Grid |
---|---|---|---|---|

Uniaxial tension test | 12 | 12 | 12 | 12 |

Uniaxial compression test | 6 | 6 | 6 | 6 |

Uniaxial compression test (mixture without fiber) | 6 | 6 | 6 | 6 |

Single crack tension test | 6 | 6 | 6 | 6 |

Three-point bending test | 3 | 3 | 3 | 3 |

Three-point bending test (mixture without fiber) | 3 | 3 | 3 | 3 |

Fracture toughness test (mixture without fiber) | 3 | 3 | 3 | 3 |

Mixture ID | Crack Number (80 mm) | Crack Width (μm) | Crack Spacing (mm) |
---|---|---|---|

RS-ECC-20 grid | 44 | 117 | 1.93 |

RS-ECC-12 grid | 37 | 119 | 2.16 |

NS-ECC-20 grid | 29 | 125 | 2.69 |

NS-ECC-12 grid | 26 | 145 | 3.03 |

Mixture ID | First Cracking Stress (N/mm ^{2}) | Cracking Strain (%) | Peak Tensile Stress (N/mm ^{2}) | Strain at Peak Stress (%) | Peak Tensile Stress/First Cracking Stress | Strain at 85% of the Peak Stress (%) |
---|---|---|---|---|---|---|

Normal ECC | 1.68 | 0.02 | 4.27 | 4.76 | 2.54 | 7.22 |

RS-ECC-20 grid | 2.21 | 0.08 | 4.75 | 7.00 | 2.15 | 8.22 |

RS-ECC-12 grid | 2.03 | 0.07 | 4.18 | 5.52 | 2.06 | 6.73 |

NS-ECC-20 grid | 1.97 | 0.03 | 3.96 | 4.64 | 2.01 | 5.32 |

NS-ECC-12 grid | 1.88 | 0.02 | 3.86 | 4.78 | 2.05 | 5.88 |

Mixture ID | Peak Compressive Strength (MPa) | Peak Flexural Strength (MPa) | Mid-Span Deformation at Peak Flexural Strength (mm) |
---|---|---|---|

RS-plain-20 grid | 35.91 | 7.55 | / |

RS-plain-12 grid | 42.50 | 7.43 | / |

NS-plain-20 grid | 40.91 | 8.87 | / |

NS-plain-12 grid | 38.66 | 8.86 | / |

RS-ECC-20 grid | 54.86 | 21.10 | 7.37 |

RS-ECC-12 grid | 53.65 | 20.65 | 4.45 |

NS-ECC-20 grid | 74.73 | 24.87 | 3.65 |

NS-ECC-12 grid | 52.88 | 24.40 | 5.89 |

Mixture ID | Parameter | Average | Variance |
---|---|---|---|

RS-ECC-20 grid | σ_{OC} (Mpa) | 4.32 | 0.12 |

δ_{B} (mm) | 0.81 | 0.07 | |

RS-ECC-12 grid | σ_{OC} (Mpa) | 5.02 | 0.45 |

δ_{B} (mm) | 0.73 | 0.05 | |

NS-ECC-20 grid | σ_{OC} (Mpa) | 4.55 | 0.18 |

δ_{B} (mm) | 1.08 | 0.14 | |

NS-ECC-12 grid | σ_{OC} (Mpa) | 5.03 | 0.24 |

δ_{B} (mm) | 0.65 | 0.00 |

Mixture ID | Specimen | Mass (kg) | Peak Load F_{Q} (kN) | Fracture Toughness K _{Q} (MPa·m^{1/2}) | Fracture Energy J _{tip}(J/m ^{2}) |
---|---|---|---|---|---|

RS-plain-20 grid | 1 | 2.02 | 0.55 | 0.43 | 11.44 |

2 | 2.10 | 0.44 | 0.34 | 7.29 | |

3 | 1.98 | 0.53 | 0.41 | 10.53 | |

Average | 2.03 | 0.51 | 0.39 | 10.99 | |

RS-plain-12 grid | 1 | 2.02 | 0.45 | 0.35 | 7.47 |

2 | 2.01 | 0.52 | 0.40 | 9.96 | |

3 | 1.98 | 0.45 | 0.35 | 7.44 | |

Average | 2.00 | 0.52 | 0.36 | 8.29 | |

NS-plain-20 grid | 1 | 2.06 | 0.63 | 0.50 | 14.92 |

2 | 2.15 | 0.67 | 0.52 | 16.92 | |

3 | 2.09 | 0.69 | 0.53 | 17.68 | |

Average | 2.10 | 0.67 | 0.51 | 16.51 | |

NS-plain-12 grid | 1 | 2.07 | 0.59 | 0.46 | 12.96 |

2 | 2.13 | 0.59 | 0.46 | 12.96 | |

3 | 2.10 | 0.62 | 0.48 | 14.27 | |

Average | 2.10 | 0.60 | 0.47 | 13.40 |

Mixture ID | J_{b}′ (J/m^{2}) | J_{tip} (J/m^{2}) | J_{b}′/J_{tip} (PSH) | ε_{t} (%) |
---|---|---|---|---|

RS-ECC-20 grid | 1552.15 | 10.99 | 141.23 | 8.22 |

RS-ECC-12 grid | 1668.61 | 8.29 | 201.28 | 6.73 |

NS-ECC-20 grid | 1597.55 | 16.51 | 96.76 | 5.32 |

NS-ECC-12 grid | 1585.17 | 13.40 | 118.30 | 5.88 |

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**MDPI and ACS Style**

Dong, Z.; Tan, Y.; Jian, X.; Yu, J.; Yu, K.
The Effect of Recycled Sand on the Tensile Properties of Engineered Cementitious Composites. *Sustainability* **2022**, *14*, 13530.
https://doi.org/10.3390/su142013530

**AMA Style**

Dong Z, Tan Y, Jian X, Yu J, Yu K.
The Effect of Recycled Sand on the Tensile Properties of Engineered Cementitious Composites. *Sustainability*. 2022; 14(20):13530.
https://doi.org/10.3390/su142013530

**Chicago/Turabian Style**

Dong, Zhifu, Yan Tan, Xiangru Jian, Jiangtao Yu, and Kequan Yu.
2022. "The Effect of Recycled Sand on the Tensile Properties of Engineered Cementitious Composites" *Sustainability* 14, no. 20: 13530.
https://doi.org/10.3390/su142013530