Experimental Investigation on the Effect of Curing Condition and Admixture on Meso-Structure of Recycled Aggregate Concrete Based on X-ray CT

International Journal of Concrete Structures and Materials

Research

Yuzhu Guo¹  Xudong Chen¹  Weihong Xuan²  Yuzhi Chen³  Yingjie Ning⁴ 

[1] College of Civil and Transportation Engineering, Hohai University, 210098, Nanjing, China;School of Architectural Engineering, Jinling Institute of Technology, 211169, Nanjing, China;School of Architectural Engineering, Jinling Institute of Technology, 211169, Nanjing, China;College of Civil and Transportation Engineering, Hohai University, 210098, Nanjing, China;Zhejiang Communications Construction Group Co., Ltd, 310051, Hangzhou, China;

关键词: Steam curing;    X-ray CT;    Pore structure;    Meso-structure;    Fractal dimension;   

DOI  :  10.1186/s40069-022-00572-2

 received in 2022-06-27, accepted in 2022-11-01,  发布年份 2022

来源: Springer

【 摘 要 】

This study addresses the meso-structure of recycled aggregate concrete with different admixture and c;uring condition. The RCA (Recycled concrete aggregate) with admixture of slag power and fly ash and curing condition of steam was casted. X-ray CT (Computed tomography) was used to obtain meso-structure of RCA, and the pore structure, aggregate, and interface traction zone were analyzed. The results show that steam curing not only increases the pore volume but also makes the pore morphology more complex, the fractal dimension increases, the proportion of spherical pores decreases, and the pores develop from spherical to flat and slender with the increase of steam curing temperature. The porosity of micron pores in recycled aggregate concrete is about 2.3%, in which the pores with aperture less than 300 μm accounts for more than 85%. The thickness of the interface area between recycled aggregate and new mortar is about 200 μm, and the crack width in recycled aggregate is about 300– 400 μm.

【 授权许可】

CC BY   
© The Author(s) 2022

【 图 表 】

Fig. 1

Fig. 5

Fig. 3

Fig. 1

Fig. 1

Fig. 5

Fig. 6

40854_2022_419_Article_IEq15.gif

Fig. 5

Fig. 2

40517_2023_248_Article_IEq37.gif

40517_2023_248_Article_IEq29.gif

40517_2023_248_Article_IEq15.gif

40517_2023_248_Article_IEq1.gif