scholarly journals Prediction of Chloride Ion Penetration of Recycled Aggregate Concrete

2015 ◽  
Vol 18 (2) ◽  
pp. 427-440 ◽  
Author(s):  
Rui Vasco Silva ◽  
Jorge de Brito ◽  
Rui Neves ◽  
Ravindra Dhir
2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Yuan Zuo ◽  
Bing Qi ◽  
Jianming Gao ◽  
Weibin Li

The penetration paths of chloride ions in recycled aggregate concrete (RAC) are of significant interest and have not been well studied previously. This study used X-ray computed tomography (X-CT) as a novel approach to investigate chloride ion penetration paths in RAC. The results indicate that X-CT can be used for the constant monitoring of chloride ion penetration paths in RAC, and the influence of mix proportions on the chloride ion penetration can be understood through the X-CT visualization.


2014 ◽  
Vol 629-630 ◽  
pp. 173-182 ◽  
Author(s):  
Gai Fei Peng ◽  
Juan Yang ◽  
Jing Yan Wang

An experimental investigation was conducted on the durability of recycled aggregate concretes with the water to binder ratios of 0.26 and 0.60, including chloride ion penetration resistance test, freezing-thawing resistance test and water penetration resistance. Natural aggregate, recycled aggregate untreated and recycled aggregate treated by sulfuric acid solution, were employed. Results indicated that, 3 mol/L acid concentration and the 7 days soaking duration was the optimum to remove the attached mortars in recycled aggregate, and its removal rate could reach to 90.8%. Water penetration resistance, chloride ion penetration resistance and freezing-thawing resistance of concrete with 0.26 W/B was superior to that of concrete with 0.60 W/B. The more pores in the internal of concrete with 0.60 W/B could be attributed to that. Durability of recycled aggregate concrete, incorporating recycled aggregate treated by sulfuric acid solution, was improved. In particular, the improvement in recycled high strength concrete was significant.


2011 ◽  
Vol 460-461 ◽  
pp. 764-767 ◽  
Author(s):  
Yi Dong Xu ◽  
Jia Ying Sun

Influence of recycled aggregate on slump, compressive strength and chloride ion permeability of recycled aggregate concrete was investigated. As is shown by the results, although recycled aggregate belongs to the category of poor quality aggregate, the properties of high performance recycled aggregate concrete are not reduced dramatically with the increasing amount of recycled aggregate, for recycled aggregate have both positive effects and negative effects on the properties of recycled aggregate concrete. The high performance recycled aggregate concrete can be developed by double-mixture of ultra fine fly ash and superplasticizer.


2020 ◽  
Vol 2 (1) ◽  
pp. 045-045

Aim & Scope: Sustainability requires a judicious use of natural resources. Reducing the consumption of natural aggregates and ensuring adequate durability of reinforced concrete infrastructures are major steps towards sustainability. Performance-based Service Life Design and recycled aggregate concrete are intense research fields. Considering the research maturity of each subject on its own, it is time to couple them and deliver knowledge on performance-based Service Life Design for reinforced concrete structures incorporating recycled aggregates. This Special Issue of Materials International constitutes a way to disseminate results and findings from original studies, experimental programs, empirical, analytical and numerical modelling of initiation period (carbonation- and chloride ion-related), propagation period or both (service life). Probabilistic, semi-probabilistic and deterministic approaches are welcome.


2020 ◽  
pp. 136943322097477
Author(s):  
Yijie Huang ◽  
Jianzhuang Xiao ◽  
Li Qin ◽  
Peng Li

An experimental program was undertaken to study the mechanical behaviors of glass fiber-reinforced polymer (GFRP) tube confined recycled aggregate concrete with sea sand (GRACSS) under the axial compression. Two different parameters were mainly considered: recycled coarse aggregates (RCA) replacement percentage (0, 100%) and type of sand (sea sand, river sand). Typical influences of RCA and sea sand on the strength, the deformation and the load–deformation curve of GRACSS were investigated. The test results showed that the failure pattern of GRACSS was similar to that of GFRP tube confined ordinary concrete (GCOC). The strength of GRACSS decreased with an increasing RCA replacement percentage, while sea sand could reduce the negative effect of RCA. It is also found that the peak deformation of GRACSS increased with the increasing RCA replacement percentage whereas with decreasing sea sand chloride ion (Cl–) content. The stiffness of the specimen was obviously influenced by the concrete type. Research findings indicated that the axial load-deformation curve of GRACSS can be divided into elastic-plastic and hardening stages. An analytical expression was proposed to calculate the load-deformation curve of GRACSS. Finally, the finite element method (FEM) was applied to study the effects of outer tube thickness, concrete strength, RCA replacement percentage and Cl– content in sea sand on the mechanical behaviors (strength and deformation) of GRACSS.


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