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

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

doi:10.3390/fractalfract6010022

Cited by 24 publications

(14 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fractal theory is a new method of mathematics, resolving the irregularities in nature [67][68][69][70]. Many researchers [71][72][73][74][75][76][77][78] demonstrated that fractal theory links microstructures with the macro-performance of cement-based materials well, and vice versa.…”

Section: Fractal Dimension Calculationmentioning

confidence: 99%

Influence of MgO on the Hydration and Shrinkage Behavior of Low Heat Portland Cement-Based Materials via Pore Structural and Fractal Analysis

Wang

Liu

et al. 2022

Fractal Fract

Self Cite

View full text Add to dashboard Cite

Currently, low heat Portland (LHP) cement is widely used in mass concrete structures. The magnesia expansion agent (MgO) can be adopted to reduce the shrinkage of conventional Portland cement-based materials, but very few studies can be found that investigate the influence of MgO on the properties of LHP cement-based materials. In this study, the influences of two types of MgO on the hydration, as well as the shrinkage behavior of LHP cement-based materials, were studied via pore structural and fractal analysis. The results indicate: (1) The addition of reactive MgO (with a reactivity of 50 s and shortened as M50 thereafter) not only extends the induction stage of LHP cement by about 1–2 h, but also slightly increases the hydration heat. In contrast, the addition of weak reactive MgO (with a reactivity of 300 s and shortened as M300 thereafter) could not prolong the induction stage of LHP cement. (2) The addition of 4 wt.%–8 wt.% MgO (by weight of binder) lowers the mechanical property of LHP concrete. Higher dosages of MgO and stronger reactivity lead to a larger reduction in mechanical properties at all of the hydration times studied. M300 favors the strength improvement of LHP concrete at later ages. (3) M50 effectively compensates the shrinkage of LHP concrete at a much earlier time than M300, whereas M300 compensates the long-term shrinkage more effectively than M50. Thus, M300 with an optimal dosage of 8 wt.% is suggested to be applied in mass LHP concrete structures. (4) The addition of M50 obviously refines the pore structures of LHP concrete at 7 days, whereas M300 starts to refine the pore structure at around 60 days. At 360 days, the concretes containing M300 exhibits much finer pore structures than those containing M50. (5) Fractal dimension is closely correlated with the pore structure of LHP concrete. Both pore structure and fractal dimension exhibit weak (or no) correlations with shrinkage of LHP concrete.

show abstract

Section: Fractal Dimension Calculationmentioning

confidence: 99%

Influence of MgO on the Hydration and Shrinkage Behavior of Low Heat Portland Cement-Based Materials via Pore Structural and Fractal Analysis

Wang

Liu

et al. 2022

Fractal Fract

Self Cite

View full text Add to dashboard Cite

show abstract

“…We obtain the fractal dimension [37][38][39]. of concrete crack images by taking the logarithm of both sides of the Equation (2), as described in Equation (3).…”

Section: Fractal Dimension Of Concrete Crack Imagementioning

confidence: 99%

Segmentation of Concrete Cracks by Using Fractal Dimension and UHK-Net

Chen

Wang

et al. 2022

Fractal Fract

Self Cite

View full text Add to dashboard Cite

Concrete wall surfaces are prone to cracking for a long time, which affects the stability of concrete structures and may even lead to collapse accidents. In view of this, it is necessary to recognize and distinguish the concrete cracks. Then, the stability of concrete will be known. In this paper, we propose a novel approach by fusing fractal dimension and UHK-Net deep learning network to conduct the semantic recognition of concrete cracks. We first use the local fractal dimensions to study the concrete cracking and roughly determine the location of concrete crack. Then, we use the U-Net Haar-like (UHK-Net) network to construct the crack segmentation network. Ultimately, the different types of concrete crack images are used to verify the advantage of the proposed method by comparing with FCN, U-Net, YOLO v5 network. Results show that the proposed method can not only characterize the dark crack images, but also distinguish small and fine crack images. The pixel accuracy (PA), mean pixel accuracy (MPA), and mean intersection over union (MIoU) of crack segmentation determined by the proposed method are all greater than 90%.

show abstract

“…It can be used for PCSBs to reduce the dead load, save costs in bridge maintenance, prolong service life, and improve structural behavior. In addition, high-strength concrete has a high uniform density and very low impermeability, which is conducive to the durability of concrete buildings [23,24]. Few experimental results have been reported in the literature on the shear behavior of PHCSBs with compressive concrete strength exceeding 55 MPa, especially about the combined use of dry joints and external tendons.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Shear Behavior of Precast High-Strength Concrete Segmental Beams with External Tendons and Dry Joints

Zhang

et al. 2022

Buildings

Self Cite

View full text Add to dashboard Cite

Precast high-strength concrete segmental beams with external tendons and dry joints (ED-PHCSBs) have become a potential alternative for achieving accelerated bridge construction due to their lighter self-weight and easier installation. In order to investigate the shear behavior of ED-PHCSBs, eight precast concrete segmental specimens were fabricated and tested to failure. For comparison purposes, one externally prestressed high-strength concrete monolithic beam was also investigated. The primary parameters, including concrete strength, shear span-depth ratio, stirrup ratio, joint number, and joint location, were adopted. Test results indicated that increasing the concrete strength or stirrup ratio can effectively improve the shear capacity of the ED-PHCSBs. The shear span-depth ratio was inversely proportional to shear strength for all specimens. The results also revealed that the joint number had a marginal effect on the defections and stresses of the external tendons of ED-PHCSBs. AASHTO 2017 and Chinese code 2018 can conservatively estimate the shear strength of ED-PHCSBs. Considering the actual failure modes of the precast beams, a calculation method based on a modified strut-and-tie model was proposed. The average and standard deviation of the ratios of the test results to the predicted value of the proposed method were 0.98 and 0.08, respectively. It indicated that the proposed formula was more accurate.

show abstract

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

Cited by 24 publications

References 79 publications

Influence of MgO on the Hydration and Shrinkage Behavior of Low Heat Portland Cement-Based Materials via Pore Structural and Fractal Analysis

Influence of MgO on the Hydration and Shrinkage Behavior of Low Heat Portland Cement-Based Materials via Pore Structural and Fractal Analysis

Segmentation of Concrete Cracks by Using Fractal Dimension and UHK-Net

Experimental Study on Shear Behavior of Precast High-Strength Concrete Segmental Beams with External Tendons and Dry Joints

Contact Info

Product

Resources

About