Improving the properties of recycled concrete aggregate with bio-deposition approach

In this study, a new bio-deposition approach was used to improve the properties of recycled concrete aggregate (RCA). The new bio-deposition approach is based on bacterially induced CaCO3 precipitation through respiration, which differs from the traditional bio-deposition treatment that produces CaC...

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Bibliographic Details
Published inCement & concrete composites Vol. 94; pp. 248 - 254
Main Authors Wu, Chun-Ran, Zhu, Ya-Guang, Zhang, Xiao-Tong, Kou, Shi-Cong
Format Journal Article
LanguageEnglish
Published Elsevier Ltd 01.11.2018
Subjects
Bio-deposition treatment
CaCO3 precipitation
Properties
Recycled concrete aggregate
RCA
B-RCA
C-RCA
CaCO3 precipitation
EDS
Bio-deposition treatment
SEM
U-RCA
Properties
ITZ
Recycled concrete aggregate
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Summary:In this study, a new bio-deposition approach was used to improve the properties of recycled concrete aggregate (RCA). The new bio-deposition approach is based on bacterially induced CaCO3 precipitation through respiration, which differs from the traditional bio-deposition treatment that produces CaCO3 by urea hydrolysis. The experimental investigation was conducted in two parts. First, the physical properties including water absorption, crushing value, and density of the bio-deposition-treated RCA were determined. Then, the workability, compressive strength, and water absorption of mortars prepared with treated RCA were determined. It was found that the bio-deposition-treated RCA had a higher density and lower crushing value and water absorption compared with untreated RCA. In case of mortar, not only the workability, but also the compressive strength improved and the water absorption decreased. Moreover, the effect of bio-deposition treatment on the RCA surface and interfacial transition zone was observed by SEM. [Display omitted]
ISSN:0958-9465
1873-393X
DOI:10.1016/j.cemconcomp.2018.09.012