Impact of chloride intrusion on the pore structure of recycled aggregate concrete based on the recycled aggregate porous interface

2020 ◽  
Vol 259 ◽  
pp. 120397
Author(s):  
Huawei Liu ◽  
Chao Liu ◽  
Guoliang Bai ◽  
Chao Zhu
Keyword(s):  
Pore Structure ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Aggregate Concrete ◽  
Porous Interface

scholarly journals The Permeability of Waste Fiber Recycled Concrete

2019 ◽  
Vol 26 (2) ◽  
pp. 210-217 ◽  
Author(s):  
Jinghai ZHOU ◽  
Tianbei KANG ◽  
Fengchi WANG
Keyword(s):  
Fractal Dimension ◽  
Pore Structure ◽  
Gas Permeability ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Recycled Aggregates ◽  
Replacement Rate ◽  
Aggregate Concrete ◽  
Cement Ratio

Permeability is one of the major performances for recycled aggregate concrete, which affects the durability and service life of concrete structures. In most cases, the main factor affecting the permeability of recycled aggregate concrete is the pore structure. Considering water-cement ratio, replacement rate of recycled aggregates, waste fiber length, and volume fraction of waste fibers as the design variables, pore structure and gas permeability were studied experimentally. In addition, fractal theory was here used to assess the pore structure of waste fiber recycled concrete and study the effects of pore structure on permeability. The results showed that the pore size distribution had a small impact on the permeability with the water-cement ratio and replacement rate of recycled aggregates increasing. The fractal dimension can be used to describe the complexity of the pore structure quantitatively. There is an obvious linear relationship between fractal dimension and gas permeability. The larger the pore volume fractal dimension, the better the impermeability of waste fiber recycled concrete.

scholarly journals Pore Structure and Influence of Recycled Aggregate Concrete on Drying Shrinkage

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Yuanchen Guo ◽  
Jueshi Qian ◽  
Xue Wang
Keyword(s):  
Fractal Dimension ◽  
Pore Structure ◽  
Drying Shrinkage ◽  
Recycled Concrete ◽  
Recycled Aggregate Concrete ◽  
Recycled Aggregate ◽  
Water Evaporation ◽  
Concrete Aggregate ◽  
Aggregate Concrete ◽  
Mercury Intrusion

Pore structure plays an important role in the drying shrinkage of recycled aggregate concrete (RAC). High-precision mercury intrusion and water evaporation were utilized to study the pore structure of RAC, which has a different replacement rate of recycled concrete aggregate (RCA), and to analyze its influence on drying shrinkage. Finally, a fractal-dimension calculation model was established based on the principles of mercury intrusion and fractal-geometry theory. Calculations were performed to study the pore-structure fractal dimension of RAC. Results show the following. (1) With the increase in RCA content, the drying shrinkage values increase gradually. (2) Pores with the greatest impact on concrete shrinkage are those whose sizes ranging from 2.5 nm to 50 nm and from 50 nm to 100 nm. In the above two ranges, the proportions of RAC are greater than those of RC0 (natural aggregate concrete, NAC), which is the main reason the shrinkage values of RAC are greater than those of NAC. (3) The pore structure of RAC has good fractal feature, and the addition of RCA increases the complexity of the pore surface of concrete.

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