Effects of Nanomaterials Reinforced Aggregate on Mechanical Properties and Microstructure of Recycled Brick Aggregate Concrete

Wang, Ting; WANG, Qingshan; CUI, Shenao; YI, Haihe; Su, Tian; TAN, Zhenyu

doi:10.5755/j02.ms.32715

Cited by 7 publications

(4 citation statements)

References 19 publications

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“…The performances of the main test materials met the requirements for the relevant specifications [23,24]. At the same time, based on previous results obtained by the research group, the replacement rate of recycled aggregate was 30% [18][19][20][21][22]. For the convenience of comparative analysis, the tailings dosage was 0%, 10%, 20%, 30%, 40%, 50%, 70% and 100% and the water-cement ratio and the sand ratio were 0.4 and 0.35, respectively.…”

Section: Test Materialsmentioning

confidence: 79%

“…Cui [17] used the variance analysis method to analyze the compressive strength of recycled concrete with iron tailings under different working conditions. Professor Wang of the Xi'an University of Architecture and Technology [18][19][20][21][22] conducted a systematic macro-and micro-analysis on the strength, mechanical properties, deformation properties, carbonation, freeze-thaw cycles and other durability factors of recycled concrete with tailings, which provided a valuable basis for the development of recycled concrete with tailings.…”

Section: Introductionmentioning

confidence: 99%

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Study on Erosion Characteristics and Mechanisms of Recycled Concrete with Tailings in Salt Spray Environments

Zhan

et al. 2022

Buildings

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To improve the utilization efficiency of iron tailings (IOT) and recycled coarse aggregate (RCA), the mechanical properties, erosion depth and other erosion characteristics of recycled aggregate concrete (RAC) with different IOT amounts were studied in salt spray erosion environments and the erosion mechanisms were analyzed by SEM technology. The results showed that at the same erosion age, IOT caused the compressive strength and splitting tensile strength of RAC to tend to first increase and then decrease, with the optimum mixing amount being approximately 40%. Under the same conditions, the erosion depth of RAC was much higher than that of ordinary concrete. The erosion depth first decreased and then increased with an increasing amount of IOT. When the IOT content was 30–40%, the salt spray erosion depth reached its minimum. The solidification coefficient K1 first decreased and then increased with the increase in iron tailings content. At its lowest point, the iron tailings content was approximately between 30% and 50%, which demonstrated that the higher the salt spray erosion age, the larger the solidification coefficient. Through SEM microscopic images, it could be seen that the appropriate amount of iron tailings caused the formation of salt spray erosion crystals and that the effect of physical expansion pressure caused a reduction in the porosity of RAC and a slight increase in its mechanical properties and salt spray erosion resistance. When the iron tailings content was large, the optimal mix ratio of the concrete also changed and then harmful pores and cracks were regenerated. Therefore, resistance to salt spray erosion was weakened. The research in this paper provides a theoretical basis for the engineering application of recycled concrete with tailings in salt spray environments.

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Section: Test Materialsmentioning

confidence: 79%

Section: Introductionmentioning

confidence: 99%

Study on Erosion Characteristics and Mechanisms of Recycled Concrete with Tailings in Salt Spray Environments

Zhan

et al. 2022

Buildings

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“…The reason is that nanoparticles can not only fill the internal pores and interstices of concrete, but also act as nucleating sites for hydration products to accelerate the hydration and promote the formation of high stiffness C-S-H gels, and thus a more compact micro-structure with fewer micro-cracks can be expected and the concrete performance is improved (Gao et al 2020;Song et al 2021). In the research projects of improving properties of cement slurry or concrete, multiple types of materials with nanoparticles can be considered, such as nano-SiO2 (Khaleel et al 2018;Sanjuán et al 2018;Ying et al 2017), nano-TiO 2 (Mohseni et al 2016;Ying et al 2017), nano-Al 2 O 3 (Qin et al 2023;Wang et al 2023), nano-Fe 2 O 3 (Feng et al 2020;Laanaiya and Zaoui 2020;Sanjuán et al 2018), carbon nanotubes (Malikov 2020;Yao and Lu 2021;Zhang et al 2020) and nanoclay (Irshidat and Al-Saleh 2018), etc. However, the use of these materials in RAC does not always result in performance comparable to NAC.…”

Section: Introductionmentioning

confidence: 99%

Influence of Nano-CaCO<sub>3</sub> on the Strength and Fatigue Behavior of Concrete with 30% or 50% Recycled Coarse Aggregates

Yousheng,

Liqing,

Keqin

et al. 2024

ACT

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Recycling construction demolition waste as recycled coarse aggregate (RCA) is a value-added process. However, the utilization rate of recycled aggregate concrete (RAC) is greatly reduced due to the poor material properties of RCA itself, so it is necessary to improve the related performance of RAC for its practical engineering application. Herein, taking natural aggregate concrete (NAC), recycled aggregate concrete (RAC), recycled aggregate concrete modified with nano-CaCO 3 (NC-RAC) and natural aggregate concrete with nano-CaCO 3 (NC-NAC) as the targets, the slump test, compressive strength test, flexural strength test, static axial compressive strength test and fatigue test under different stress levels were carried out. Combined with SEM images, the basic mechanical properties and fatigue characteristics of the test concrete are analyzed, and the effects of RCA and NC are evaluated. The results indicate that the replacement of natural coarse aggregate (NCA) by RCA has a significant negative impact on the mechanical properties and fatigue properties of concrete, and the negative impact increases with the increase of RCA replacement rate. However, the incorporation of nano-CaCO 3 can significantly improve the compressive strength, flexural strength, elastic modulus and fatigue life of RAC, and effectively improve the performance of RAC materials. The recommended amount of nano-CaCO 3 is 1%. In addition, the fatigue life of the test concrete conforms to the Weibull distribution. The S-N-P fatigue equation considering the survival probability is established by fitting analysis, which has guiding significance for the application of RAC and NC-RAC in structures that need to withstand cyclic loads.

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“…Research has found that waste concrete can be crushed to produce recycled aggregates, thereby preparing recycled concrete. This can not only handle waste concrete but also solve natural stone resources [4,5].…”

Section: Introductionmentioning

confidence: 99%

Mechanical Properties of Recycled Concrete with Polypropylene Fiber and Its Bonding Performance with Rebars

SUN,

DU,

SUN

et al. 2024

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This paper explores the influence of polypropylene fiber on the mechanical properties of recycled concrete and the bonding performance between recycled concrete and steel bars. The results indicate that the compressive strength and splitting tensile strength of concrete decrease with the increase in the replacement rate of recycled aggregate. When the replacement rate of recycled aggregate was 100 %, the compressive strength of concrete decreased by 25.0%, while the splitting tensile strength of concrete decreased by 21.7 %. The compressive strength and splitting tensile strength of recycled aggregate concrete show a trend of first increasing and then decreasing with increasing fiber content. When the fiber content is 0.09 %, the compressive strength and tensile strength of recycled aggregate concrete are optimal. The bond strength of recycled concrete pullout specimens with fiber is higher than that of recycled concrete pullout specimens without fiber, while the slip of recycled concrete pullout specimens with fiber is lower than that of recycled concrete pullout specimens without fiber. The maximum improvement in bonding performance between recycled concrete and rebars with a 50 % recycled aggregate replacement rate is 13.7 %, and the maximum improvement in bonding performance between recycled concrete and rebars with a 100 % recycled aggregate replacement rate is 11.8 %. The bond strength shows a trend of first increasing and then decreasing with increasing fiber content, but the degree of decrease was not significant, while the slip shows a trend of first decreasing and then increasing with increasing fiber content. Compared to the compressive strength of concrete, the splitting tensile strength can better reflect the bond strength between concrete and rebar. The nonlinear relationship between the bond strength, compressive strength, and splitting tensile strength of recycled concrete is established. This study can effectively improve the mechanical properties of recycled concrete, expand the application scope of recycled concrete technology, and promote the sustainable development of the construction industry.

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Effects of Nanomaterials Reinforced Aggregate on Mechanical Properties and Microstructure of Recycled Brick Aggregate Concrete

Cited by 7 publications

References 19 publications

Study on Erosion Characteristics and Mechanisms of Recycled Concrete with Tailings in Salt Spray Environments

Study on Erosion Characteristics and Mechanisms of Recycled Concrete with Tailings in Salt Spray Environments

Influence of Nano-CaCO<sub>3</sub> on the Strength and Fatigue Behavior of Concrete with 30% or 50% Recycled Coarse Aggregates

Mechanical Properties of Recycled Concrete with Polypropylene Fiber and Its Bonding Performance with Rebars

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