Effect of Saturation Degree on Salt Frost Resistance Durability of Recycled Coarse Aggregate Concrete

2021 ◽  
Author(s):  
Haoxiang Luan ◽  
Jin Wu ◽  
Xing Zhao ◽  
Fei Geng
2017 ◽  
Vol 898 ◽  
pp. 2046-2049 ◽  
Author(s):  
Gong Bing Yue ◽  
Qiu Yi Li ◽  
Jian Lin Luo ◽  
Yuan Xin Guo

Compared with natural aggregate, the content of hardening cement in recycled aggregate is larger, which leads that the water absorption of recycled aggregate is larger and its performance such as robustness is poorer. And the engineering field pays much attention to the problem of the recycled fine aggregate which can be used in the durability requirements of recycled concrete or not. Using the method of fast freezing and thawing the influence of quality and replacement ratio of recycled coarse aggregate on the frost resistance of recycled concrete was researched basing on ordinary concrete frost resistance performance. The results showed that, in terms of the frost resistance capacity, the order is in: ordinary concrete>high-quality recycled coarse aggregate concrete>normal quality recycled coarse aggregate concrete. After 250 freeze-thaw cycles, the mass loss rate of general quality recycled coarse aggregate concrete is 5%, relative dynamic elastic modulus is 60% when replace rate was 100%.


2014 ◽  
Vol 584-586 ◽  
pp. 1456-1460
Author(s):  
Chun Hong Chen ◽  
Ping Hua Zhu ◽  
Jun Yong Wu ◽  
Lei Yi

The influence of recycled aggregates on the frost resistance of concrete was studied by rapid freezing-thawing test. Results showed that there was an important effect of aggregate gradation on frost resistance of recycled coarse aggregate concrete. Frost resistance of recycled fine aggregate concrete was deteriorated with increasing the content of recycled fine aggregate, and recycled fine aggregate had a greater influence on the frost resistance of recycled aggregate concrete than recycled coarse aggregate when adding both together. Test showed that the mass loss rate and the relative dynamic elastic modulus loss are not consistent as evaluation indexes of the frost resistance for recycled concrete, and whether the mass loss rate is suitable as an indicator of frost resistance durability needs to be further studied.


2020 ◽  
Vol 12 (24) ◽  
pp. 10544
Author(s):  
Chunhong Chen ◽  
Ronggui Liu ◽  
Pinghua Zhu ◽  
Hui Liu ◽  
Xinjie Wang

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.


2011 ◽  
Vol 477 ◽  
pp. 280-289 ◽  
Author(s):  
Shao Wei Yao ◽  
Zhen Guo Gao ◽  
Chang Rui Wang

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.


Structures ◽  
2021 ◽  
Vol 34 ◽  
pp. 2996-3012
Author(s):  
Hongyuan Zhou ◽  
Houzhan Zhou ◽  
Xiaojuan Wang ◽  
Wanlin Cao ◽  
Tianyi Song ◽  
...  

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