Dataset Information

Axial Compressive Behavior of Geopolymer Recycled Lump Concrete.

ABSTRACT: To reduce the environmental pollution from cement production and the damage to natural resources from aggregate mining in the concrete industry, a relatively new concrete, termed geopolymer recycled lump concrete (GRLC), which uses geopolymer as the binding material to replace traditional cement and uses large demolished concrete lumps (DCLs) to partly replace concrete, is prepared in this study. Cubic and cylindrical GRLC specimens containing fresh geopolymer concrete and DCLs were tested under axial compression with various parameters, including the compressive strength levels of both fresh geopolymer concrete and DCLs, and the replacement ratio of DCLs. The compressive behavior of the GRLC specimens was compared with traditional cement recycled lump concrete (CRLC) specimens, with test results showing that GRLC specimens possess higher compressive strength than CRLC specimens under the same experimental conditions, which is due to the strengthening effect that fresh geopolymer concrete has on the DCLs. From the scanning electron microscope pattern of the GRLC specimen, it is found that the geopolymer bonds well with the old mortar attached to DCLs. As the replacement ratio increases from 0% to 33%, the elastic modulus of GRLC increases by 5%-11% but Poisson's ratio remains almost constant (in the 0.16-0.17 range). Based on the measured strength and the predicted results, which coincide with one another well, a modified method for predicting the compressive strength of GRLC cubic and cylindrical specimens is proposed.

SUBMITTER: Zhang H

PROVIDER: S-EPMC7040574 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature

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Axial Compressive Behavior of Geopolymer Recycled Lump Concrete.

Zhang Haiyan H Liu Jiancheng J Wu Bo B Zhang Zhijian Z

Materials (Basel, Switzerland) 20200122 3

To reduce the environmental pollution from cement production and the damage to natural resources from aggregate mining in the concrete industry, a relatively new concrete, termed geopolymer recycled lump concrete (GRLC), which uses geopolymer as the binding material to replace traditional cement and uses large demolished concrete lumps (DCLs) to partly replace concrete, is prepared in this study. Cubic and cylindrical GRLC specimens containing fresh geopolymer concrete and DCLs were tested under ...[more]

PMID: 31979081

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Project description:Geopolymer concrete is an inorganic concrete that uses industrial or agro by-product ashes as the main binder instead of ordinary Portland cement; this leads to the geopolymer concrete being an eco-efficient and environmentally friendly construction material. A variety of ashes used as the binder in geopolymer concrete such as fly ash, ground granulated blast furnace slag, rice husk ash, metakaolin ash, and Palm oil fuel ash, fly ash was commonly consumed to prepare geopolymer concrete composites. The most important mechanical property for all types of concrete composites, including geopolymer concrete, is the compressive strength. However, in the structural design and construction field, the compressive strength of the concrete at 28 days is essential. Therefore, achieving an authoritative model for predicting the compressive strength of geopolymer concrete is necessary regarding saving time, energy, and cost-effectiveness. It gives guidance regarding scheduling the construction process and removal of formworks. In this study, Linear (LR), Non-Linear (NLR), and Multi-logistic (MLR) regression models were used to develop the predictive models for estimating the compressive strength of fly ash-based geopolymer concrete (FA-GPC). In this regard, a comprehensive dataset consists of 510 samples were collected in several academic research studies and analyzed to develop the models. In the modeling process, for the first time, twelve effective variable parameters on the compressive strength of the FA-GPC, including SiO2/Al2O3 (Si/Al) of fly ash binder, alkaline liquid to binder ratio (l/b), fly ash (FA) content, fine aggregate (F) content, coarse aggregate (C) content, sodium hydroxide (SH)content, sodium silicate (SS) content, (SS/SH), molarity (M), curing temperature (T), curing duration inside ovens (CD) and specimen ages (A) were considered as the modeling input parameters. Various statistical assessments such as Root Mean Squared Error (RMSE), Mean Absolute Error (MAE), Scatter Index (SI), OBJ value, and the Coefficient of determination (R2) were used to evaluate the efficiency of the developed models. The results indicated that the NLR model performed better for predicting the compressive strength of FA-GPC mixtures compared to the other models. Moreover, the sensitivity analysis demonstrated that the curing temperature, alkaline liquid to binder ratio, and sodium silicate content are the most affecting parameter for estimating the compressive strength of the FA-GPC.

Dataset Information

Axial Compressive Behavior of Geopolymer Recycled Lump Concrete.

Publications

Axial Compressive Behavior of Geopolymer Recycled Lump Concrete.

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