Optimization of the recycled masonry aggregate concrete mixture for structural utilization

This study examined the compressive behaviors of concrete with artificial sand that mixed with different content of stone powder (SP). Forty-five cubic specimens were prepared with two strength grades and five SP-content. Including 15 specimens (C35) of recycled coarse aggregate (RA) concrete with artificial sand (RCC35), 15 specimens (C45) of recycled coarse aggregate concrete with artificial sand (RCC45) and 15 specimens (C35) of natural aggregate concrete with artificial sand (NC35). The workability of concrete mixture and the compressive strength of the cubic specimens were tested. The results showed that the slump of concrete mixture decreased with the SP-content increased, and the coagulability and water retentivity of the concrete mixture were improved by using stone powder. The compressive strength of the concrete with artificial sand were increased by incorporating stone powder. The optimal SP-content of RCC35 and NC35 is 20%, while RCC45 is 10%.

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Study Replacement of Cement with Recycled Cement Powder and the Environmental Assessment

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.249.136 ◽

2016 ◽

Vol 249 ◽

pp. 136-141 ◽

Cited By ~ 5

Author(s):

Tereza Pavlů ◽

Vladimír Kočí ◽

Magdaléna Šefflová

Keyword(s):

Environmental Assessment ◽

Life Cycle Analysis ◽

Mechanical Deformation ◽

Recycled Aggregate ◽

Concrete Mixture ◽

Partial Replacement ◽

Fine Aggregate ◽

Aggregate Concrete ◽

Cement Powder ◽

Partial Cement Replacement

This investigation is focused on possibility of partial cement replacement in concrete mixture and its environmental assessment. The cement in concrete mixture is replaced by recycled cement powder from modified construction and demolition (C&D) waste. Recycled cement powder were prepared in laboratory from C&D waste of high quality road concrete. The main goal of this investigation is optimize amount of recycled cement powder used as partial replacement of cement in concrete mixture according to mechanical, deformation and physical properties of concrete and environmental impact. The properties of the fine-aggregate concrete with partial replacement of cement by recycled cement powder were tested for this verification. The life cycle analysis was calculated for this optimization. The properties and environmental assessment of the fine-aggregate concrete with partial replacement of fine aggregate by fine recycled aggregate were examined for comparison.

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Relationship of Surface and Bulk Resistivity in the Case of Mechanically Damaged Fibre Reinforced Red Ceramic Waste Aggregate Concrete

Materials ◽

10.3390/ma13235501 ◽

2020 ◽

Vol 13 (23) ◽

pp. 5501

Author(s):

Marie Horňáková ◽

Petr Lehner

Keyword(s):

Mechanical Damage ◽

Physical Property ◽

Waste Material ◽

Concrete Mixture ◽

Fine Aggregate ◽

Bulk Resistivity ◽

Aggregate Concrete ◽

Strength Capacity ◽

Standard Specimens ◽

Wenner Probe

Electrical resistivity is an important physical property of concrete, directly related to the chloride-induced corrosion process. This paper analyses the surface resistivity (SR) and bulk resistivity (BR) of structural lightweight waste aggregate concrete (SLWAC). The studied concrete mixture contained waste material—red ceramics fine aggregate and artificial expanded clay coarse aggregate. Red ceramic is a frequent waste material remaining after the demolition of buildings or unsatisfactory building material production and is among the least used construction waste. Therefore, its use is desirable in terms of sustainability; in some cases, it can reliably replace the conventional aggregate in a concrete mixture. The relationship between SR and BR was determined in the case of standard specimens and mechanically damaged specimens (to 50% and 100% of ultimate strength capacity—USC). Two different instruments were utilised for the investigation—a 4-point Wenner probe meter and an RCON tester. The results of standard specimens support the theoretically derived correction ratio, but in the case of mechanically damaged specimens, the ratio is more scattered, which is related to the mechanical damage and the amount of fibre.

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Improvement of the Durability of Recycled Masonry Aggregate Concrete

Materials ◽

10.3390/ma13235486 ◽

2020 ◽

Vol 13 (23) ◽

pp. 5486

Author(s):

Tereza Pavlů ◽

Kristina Fořtová ◽

Jakub Řepka ◽

Diana Mariaková ◽

Jiří Pazderka

Keyword(s):

Material Properties ◽

Positive Impact ◽

Positive Influence ◽

Mineral Admixture ◽

Laboratory Evaluation ◽

Laboratory Measurements ◽

Aggregate Concrete ◽

Carbonation Resistance ◽

Recycled Masonry

The use of recycled masonry aggregate for concrete is mostly limited by the worse properties in comparison with natural aggregate. For these reasons it is necessary to find ways to improve the quality of recycled masonry aggregate concrete and make it more durable. One possibility is utilization of crystalline admixture which was verified in this study by laboratory measurements of key material properties and durability. The positive influence of mineral admixture was proved for freeze-thaw resistance. The positive impact to carbonation resistance was not unambiguous. In conclusion, the laboratory evaluation shows how to improve the durability of recycled masonry aggregate concrete, however, it is necessary to investigate more about this topic.

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A Study on Ceramsite Pre-Wetted Time to Work on the Performance of Ceramsite Aggregate Concrete

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.393-395.11 ◽

2011 ◽

Vol 393-395 ◽

pp. 11-14

Author(s):

Wei Jun Yang ◽

Peng Xiao Jiang ◽

Yan Wang

Keyword(s):

Experimental Study ◽

Influencing Factors ◽

Lightweight Aggregate ◽

Concrete Mixture ◽

Aggregate Concrete ◽

Working Performance

This paper analyzes the reasons for delamination of ceramsite aggregate concrete mixture, obtained influencing factors of working performance based on the study of equations of lightweight aggregate motion. Moreover, by experimental study of the different pre-wetted time conditions on working performance, a reasonable pre-wetted time of ceramsite before ceramsite aggregate concrete for construction is summarized as well.

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Recycled Aggregate Concrete Mixture Proportion Method Based on Pulp Content

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.584-586.1425 ◽

2014 ◽

Vol 584-586 ◽

pp. 1425-1431

Author(s):

Qing Han ◽

Zong Ming Jia ◽

Dong Ye Sun

Keyword(s):

Tensile Strength ◽

Compressive Strength ◽

Splitting Tensile Strength ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Concrete Mixture ◽

Concrete Compressive Strength ◽

Aggregate Concrete ◽

Proportion Method ◽

The Relationship

Putting forward a new recycled aggregate concrete mixture proportion method based on the pulp content by researching the effect of pulp content on recycled coarse aggregate physical properties .Research on the cube compressive strength and splitting tensile strength of recycled aggregate concrete by the proposed method and results showed that:The proposed method can reduce the dosage of cement and sand, and increase the recycled aggregate concrete compressive strength and splitting tensile strength ;Establishing the relationship formula between splitting tensile strength and compressive strength of recycled aggregate concrete upon a large number of experimental data.

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