The influence of salt-frost cycles on the bond behavior distribution between rebar and recycled coarse aggregate concrete

Abstract In this paper, an overview focusing on the bond behavior of recycled coarse aggregate concrete (RAC) with steel bar is carried out. The results show that the failure modes of RAC specimen were not only influenced by a single factor, it is necessary to comprehensively consider the influence of various factors on the failure modes of RAC specimen; The steel bar diameter, the concrete cover to diameter ratio and the replacement rate of RCA all affect the load-slip curve of RAC specimen; Bond strength predictive equations and bond-slip relationship models of RAC with steel bar has been summarized to ensure engineers to better understand their applicability; The influencing factors of the bond behavior of RAC specimens including the replacement rate of RCA, the concrete compressive strength, the steel bar type and steel bar diameter, the steel bar embedment length and the aggregate performance; The freeze-thaw cycles and the steel bar corrosion all affect the bond behavior of RAC with steel bar. When freeze-thaw damage and steel bars corrosion reach a certain degree, the bond behavior of RAC with steel bar deteriorates.

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Carbonization Durability of Two Generations of Recycled Coarse Aggregate Concrete with Effect of Chloride Ion Corrosion

Sustainability ◽

10.3390/su122410544 ◽

2020 ◽

Vol 12 (24) ◽

pp. 10544

Author(s):

Chunhong Chen ◽

Ronggui Liu ◽

Pinghua Zhu ◽

Hui Liu ◽

Xinjie Wang

Keyword(s):

Compressive Strength ◽

Coarse Aggregate ◽

Chloride Ion ◽

Total Porosity ◽

Recycled Concrete ◽

Carbonation Depth ◽

Aggregate Concrete ◽

Recycled Coarse Aggregate ◽

Carbonation Resistance ◽

Two Generations

Carbonation durability is an important subject for recycled coarse aggregate concrete (RAC) applied to structural concrete. Extensive studies were carried out on the carbonation resistance of RAC under general environmental conditions, but limited researches investigated carbonation resistance when exposed to chloride ion corrosion, which is an essential aspect for reinforced concrete materials to be adopted in real-world applications. This paper presents a study on the carbonation durability of two generations of 100% RAC with the effect of chloride ion corrosion. The quality evolution of recycled concrete coarse aggregate (RCA) with the increasing recycling cycles was analyzed, and carbonation depth, compressive strength and the porosity of RAC were measured before and after chloride ion corrosion. The results show that the effect of chloride ion corrosion negatively affected the carbonation resistance of RAC, and the negative effect was more severe with the increasing recycling cycles of RCA. Chloride ion corrosion led to a decrease in compressive strength, while an increase in carbonation depth and the porosity of RAC. The equation of concrete total porosity and carbonation depth was established, which could effectively judge the deterioration of carbonation resistance of RAC.

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Bond of recycled coarse aggregate concrete: Model uncertainty and reliability-based calibration of design equations

Engineering Structures ◽

10.1016/j.engstruct.2021.112290 ◽

2021 ◽

Vol 239 ◽

pp. 112290

Author(s):

João Nuno Pacheco ◽

Jorge de Brito ◽

Carlos Chastre ◽

Luís Evangelista

Keyword(s):

Model Uncertainty ◽

Coarse Aggregate ◽

Aggregate Concrete ◽

Recycled Coarse Aggregate ◽

Concrete Model

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A model of carbonation depth of recycled coarse aggregate concrete under axial compressive stress

European Journal of Environmental and Civil engineering ◽

10.1080/19648189.2021.1886178 ◽

2021 ◽

pp. 1-8

Author(s):

Zhenghao Zou ◽

Guojiao Yang

Keyword(s):

Compressive Stress ◽

Coarse Aggregate ◽

Carbonation Depth ◽

Aggregate Concrete ◽

Recycled Coarse Aggregate ◽

Axial Compressive Stress

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Study on Performance of Recycled Aggregate Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.477.280 ◽

2011 ◽

Vol 477 ◽

pp. 280-289 ◽

Cited By ~ 1

Author(s):

Shao Wei Yao ◽

Zhen Guo Gao ◽

Chang Rui Wang

Keyword(s):

Mechanical Properties ◽

Coarse Aggregate ◽

Physical And Mechanical Properties ◽

Recycled Aggregate Concrete ◽

Recycled Aggregate ◽

Chemical Solution ◽

Aggregate Concrete ◽

Recycled Coarse Aggregate ◽

Natural Aggregate ◽

Strength And Durability

The properties of recycled coarse aggregate and the slump, the physical and mechanical properties and durability of recycled aggregate concrete were studied through tests. The results indicate that the slump, compressive strength and durability of concrete with recycled aggregate are lower than that of concrete with natural aggregate when recycled coarse aggregate fully absorbs water. However, the slump can be similar to that of concrete with natural aggregate. The properties of recycled aggregate concrete can be improved by strengthening the recycled coarse aggregate, and it is also found that the recycled coarse aggregate strengthened by grinding is superior to that soaked by chemical solution.

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