Effect of the source concrete with ASR degradation on the mechanical and physical properties of coarse recycled aggregate

Santos, Miguel Barreto; Brito, Jorge de; Silva, António Santos; Hawreen, A.

doi:10.1016/j.cemconcomp.2020.103621

Cited by 19 publications

(4 citation statements)

References 17 publications

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“…AAR mainly includes alkali-carbonate reaction (ACR) and alkali-silica reaction (ASR) [5][6][7]. There are large number research for the ASR [8][9][10][11][12][13][14]. But for the ACR, the related research is less than ASR.…”

Section: Introductionmentioning

confidence: 99%

Research on alkali-carbonate reaction (ACR) and damage of freeze-thaw for pure dolomite as concrete coarse aggregate

Chen,

Xiong,

Wang

et al. 2024

Preprint

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Alkali-carbonate reaction (ACR) is one of the important components of alkali aggregate reaction (AAR) in concrete structures, which may lead to a serious damage for the concrete construction and effect on the durability of concrete projects adversely. Previous research has systematically investigated the possibility of ACR in dolomitic limestone. However, there is limited literature available for ACR in pure dolomite aggregate specifically. Therefore, this paper aims to investigates whether pure dolomite occur ACR and the freeze-thaw resistance of pure dolomite coarse aggregate concrete (PDCAC) due to the raw materials produced in the southwest of China, which is cold in winter. To determine the alkali activity of pure dolomite, three methods were employed: lithofacies method (LM), rock-cylinder method (RCM), and rapid preliminary screening test for carbonate aggregates (AAR-5). Lithofacies method confirmed that the dolomite used in this paper was pure almost, and no SiO2 content, ruling out the possibility of alkali-silica reaction (ASR). The rock-cylinder method indicated a reduction in length during the 84-day test period, which indicates the absence of ACR. Subsequently, the AAR-5 method was used to test ACR, and the samples exhibited a length expansion rate of far less than 0.1% within 28 days, which further confirmed the absence of alkali activity in pure dolomite. Finally, the freeze-thaw cycles test was carried out on the concrete with pure dolomite as concrete coarse aggregate. The results revealed no significant spalling on the concrete surface after 200 freeze-thaw cycles, and pure dolomite coarse aggregate concrete can withstand freeze-thaw damage to a certain extent.

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Section: Introductionmentioning

confidence: 99%

Research on alkali-carbonate reaction (ACR) and damage of freeze-thaw for pure dolomite as concrete coarse aggregate

Chen,

Xiong,

Wang

et al. 2024

Preprint

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show abstract

“…AAR mainly includes the alkali-carbonate reaction (ACR) and alkali-silica reaction (ASR) [10][11][12]. There is a large amount of research on the ASR [13][14][15][16], while little research exists on the ACR.…”

Section: Introductionmentioning

confidence: 99%

The Risk of Alkali–Carbonate Reaction and the Freeze–Thaw Resistance of Waste Dolomite Slag-Based Concrete

Chen,

Xiong,

Wang

et al. 2024

Buildings

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The alkali–carbonate reaction (ACR) is a type of alkali–aggregate reaction (AAR) that may lead to serious damage in concrete construction. There is sufficient research on the effect of the ACR on dolomite limestone; however, research on the effect of the ACR on pure dolomite is absent, and there are a large number of dolomite resources that cannot be effectively utilized in civil engineering. This study aims to investigate whether the ACR occurs in pure dolomite spoil and to determine the freeze–thaw resistance of pure waste dolomite slag-based concrete (PWDSC). In this study, X-ray diffraction (XRD) and the lithofacies method (LM) confirmed that the tested samples were pure dolomite. The rock cylinder method (RCM) and rapid preliminary screening testing for carbonate aggregates (AAR-5) were employed to determine the alkali activity of pure dolomite: the RCM indicated a variation of −0.09% in length during the 84-day test period, the AAR-5 exhibited a length expansion rate of 0.03% within 28 days, and the expansion rates were less than 0.1%. These findings suggest that pure waste dolomite slag (PWDS) does not possess alkali activity. The freeze–thaw cycle test showed no significant spalling on the concrete surface, the inside of the cement produced few micro-cracks according to scanning electron microscopy (SEM), and the uniaxial compressive strength (UCS) test showed a decrease of approximately 20% after 200 freeze–thaw cycles. The results verified that ACR does not occur in PWDS and that it can withstand freeze–thaw damage, to a certain extent, when used as concrete coarse aggregate.

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“…A total of 15 billion tons of concrete material is produced worldwide, which equates to about two tons of concrete per resident per annum [4]. To reduce this flaw and manage this demand, the origin of good quality natural aggregates is significantly reducing worldwide [5]. The approximate amount of aggregate used in the European Union countries has reached two billion each year.…”

Section: Introductionmentioning

confidence: 99%

Compressive Strength Prediction via Gene Expression Programming (GEP) and Artificial Neural Network (ANN) for Concrete Containing RCA

et al. 2021

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To minimize the environmental risks and for sustainable development, the utilization of recycled aggregate (RA) is gaining popularity all over the world. The use of recycled coarse aggregate (RCA) in concrete is an effective way to minimize environmental pollution. RCA does not gain more attraction because of the availability of adhered mortar on its surface, which poses a harmful effect on the properties of concrete. However, a suitable mix design for RCA enables it to reach the targeted strength and be applicable for a wide range of construction projects. The targeted strength achievement from the proposed mix design at a laboratory is also a time-consuming task, which may cause a delay in the construction work. To overcome this flaw, the application of supervised machine learning (ML) algorithms, gene expression programming (GEP), and artificial neural network (ANN) was employed in this study to predict the compressive strength of RCA-based concrete. The linear coefficient correlation (R2), mean absolute error (MAE), mean square error (MSE), and root mean square error (RMSE) were evaluated to investigate the performance of the models. The k-fold cross-validation method was also adopted for the confirmation of the model’s performance. In comparison, the GEP model was more effective in terms of prediction by giving a higher correlation (R2) value of 0.95 as compared to ANN, which gave a value of R2 equal to 0.92. In addition, a sensitivity analysis was conducted to know about the contribution level of each parameter used to run the models. Moreover, the increment in data points and the use of other supervised ML approaches like boosting, gradient boosting, and bagging to forecast the compressive strength, would give a better response.

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Effect of the source concrete with ASR degradation on the mechanical and physical properties of coarse recycled aggregate

Cited by 19 publications

References 17 publications

Research on alkali-carbonate reaction (ACR) and damage of freeze-thaw for pure dolomite as concrete coarse aggregate

Research on alkali-carbonate reaction (ACR) and damage of freeze-thaw for pure dolomite as concrete coarse aggregate

The Risk of Alkali–Carbonate Reaction and the Freeze–Thaw Resistance of Waste Dolomite Slag-Based Concrete

Compressive Strength Prediction via Gene Expression Programming (GEP) and Artificial Neural Network (ANN) for Concrete Containing RCA

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