Treatment Methods for the Quality Improvement of Recycled Concrete Aggregate (RCA) - A Review

Ding, Yao; Wu, Jun; Xu, Ping; Zhang, Xianggang; Fan, Yongzhe

doi:10.1007/s11595-021-2380-3

Cited by 27 publications

(8 citation statements)

References 122 publications

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“…The VAF is allowed to reach 100%, and PPE is allowed to reach 0% when the model is equal to the true system. Theoretically, the computational complexity of the proposed APM per iteration is O(N 2 ), which is obviously more computationally demanding than O(N) in the TSA, because of the projection operations [17]. Fortunately, from the averaged estimation results of Euclidean norm θ for 100 MC simulations at each iteration in APM under different SNRs shown in Figure 1, we observe that APM converges very quickly within 4 iterations for high SNRs (e.g., 20 and 25 dB), and also provides accurate estimation results even for a low SNR of 15 dB.…”

Section: Case Studiesmentioning

confidence: 99%

A Robust Hammerstein-Wiener Model Identification Method for Highly Nonlinear Systems

et al. 2022

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The existing results show the applicability of the Over-Parameterized Model based Hammerstein-Wiener model identification methods. However, it requires to estimate extra parameters and performer a low rank approximation step. Therefore, it may give rise to unnecessarily high variance in parameter estimates for highly nonlinear systems, especially using a small and noisy data set. To overcome this corruptive phenomenon. To overcome this corruptive phenomenon, in this paper, a robust Hammerstein-Wiener model identification method is developed for highly nonlinear systems when using a small and noisy data set, where two parsimonious parametrization models with fewer parameters are used, and an iteration method is then used to retrieve the true system parameters from the parametrization models. Such modification can improve the parameter estimation performance in terms of accuracy and variance compared with the over-parametrization model based identification methods. All the above-mentioned developments are analyzed with variance analysis, along with a simulation example to confirm the effectiveness.

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Section: Case Studiesmentioning

confidence: 99%

A Robust Hammerstein-Wiener Model Identification Method for Highly Nonlinear Systems

et al. 2022

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“…The present problem is the search for climate compatible concrete which should be easily disposed in normal landfills, further recycled and , Hoornweg et al [33], Ding [34], have reported that the recycling C & D waste which is fit for recycling are separated, stockpiled and loaded to the conveyor after stamping removal of scraps and trashes. Later crushed in crusher, graded screened, and he final product However the C&D wastes recovered from pavements, matured brick constructions may not selected for RCA generations and may be used for landfill as they consume energy during…”

Section: Recycled Aggregates Productionmentioning

confidence: 99%

“…The recycled coarse aggregate (RCA) may have additives like metals, tiles, plastics, iron, aluminum, flotsam and jetsam as trash which may be discarded as heterogeneous. But homogenous demolished concrete blocks, brick bats, and waste concrete can be recycled and reused as RCA.Rodríguez, et al[32], Hoornweg et al et al[34], have reported that the recycling C & D waste which is fit for recycling are separated, stockpiled and loaded to the conveyor after stamping removal of scraps and trashes. Later crushed in crusher, graded screened, and washed for quality enhance and the final product is RCA, (Fig 4.).…”

mentioning

confidence: 99%

Management of Construction and Demolished Waste as an Aggregate Substitute in Cement Concrete

Mahakud

Mishra

Mohanty

et al. 2021

IJECC

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India is in the process of modernization in the construction sector by repairing, renovation, up-gradation. Presently concrete, the universal building materials whose main ingredient is coarse aggregate. The local natural resources like stone products and sand may exhaust and put the sector deficient of aggregates. The wise use is to reuse recycled concrete and demolition wastes generated from the construction sectors due to shift from horizontal to vertical growth of urban areas. The replacement of recycled coarse aggregate shall efficiently organize the waste management, moderate the environment degradation, and upsurge sustainability. Use of recycling material in the construction industry as a recycled concrete is highly challenging. So our project deals about reusing of demolished concrete blocks from C &D wastes by form of Recycled coarse aggregate (RCA) are replacing the Natural coarse aggregate in concrete and use in the construction industry. The replacement of RCA in special concrete of 7 and 28 days of curing and the various physical and mechanical properties of materials and strength test of both concrete such as workability, compressive strength, split tensile strength and flexural strength. The test value are compared both in concrete. Our project investigates on recycling demolished waste materials in order to reduce construction cost and resolving housing problems faced by the low-income communities of the world. The crushed demolished concrete wastes is segregated by sieving to obtain required sizes of aggregate, several tests were conducted to determine the aggregate properties before recycling it into new concrete.

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“…Methods for treating recycled concrete aggregate are manifold, and new ones are still being proposed. They can be divided into two groups [15][16][17]. The first group includes methods aimed at removing as much as possible the old mortar adhering to the grains of the original natural aggregate.…”

Section: Introductionmentioning

confidence: 99%

Influence of Citric Acid-Assisted Impregnation of Recycled Aggregate on the Properties of the Resultant Concrete

2023

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The paper presents the results of tests on concrete with recycled aggregate impregnated with the use of citric acid. Impregnation was carried out in two stages, with a suspension of calcium hydroxide in water (so-called milk of lime) or diluted water glass used as the second impregnant. The mechanical properties of the concrete were carried out: compressive strength, tensile strength and resistance to cyclic freezing. In addition, concrete durability parameters such as water absorption, sorptivity and torrent air permeability were investigated. The tests showed that this type of impregnation did not improve most of the parameters of concrete with impregnated recycled aggregate. The mechanical parameters after 28 days were significantly lower compared to the reference concrete, although after a longer curing period, these differences decreased significantly for some series. The durability parameters of the concrete with impregnated recycled aggregate also deteriorated compared to the reference concrete with the exception of air permeability. The results of the tests carried out indicate that impregnation using water glass in combination with citric acid gives the best results in most cases and that the order in which the impregnation solutions are applied is very important. Tests also showed that the effectiveness of impregnation is very much influenced by the value of the w/c ratio.

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Treatment Methods for the Quality Improvement of Recycled Concrete Aggregate (RCA) - A Review

Cited by 27 publications

References 122 publications

A Robust Hammerstein-Wiener Model Identification Method for Highly Nonlinear Systems

A Robust Hammerstein-Wiener Model Identification Method for Highly Nonlinear Systems

Management of Construction and Demolished Waste as an Aggregate Substitute in Cement Concrete

Influence of Citric Acid-Assisted Impregnation of Recycled Aggregate on the Properties of the Resultant Concrete

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