scholarly journals Experimental Study on Sand Stabilization Using Bio-Cementation with Wastepaper Fiber Integration

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5164
Author(s):  
Meiqi Chen ◽  
Sivakumar Gowthaman ◽  
Kazunori Nakashima ◽  
Shin Komatsu ◽  
Satoru Kawasaki

Recently, green materials and technologies have received considerable attention in geotechnical engineering. One of such techniques is microbially-induced carbonate precipitation (MICP). In the MICP process, CaCO3 is achieved bio-chemically within the soil, thus enhancing the strength and stiffness. The purpose of this study is to introduce the wastepaper fiber (WPF) onto the MICP (i) to study the mechanical properties of MICP-treated sand with varying WPF content (0–8%) and (ii) to assess the freeze–thaw (FT) durability of the treated samples. Findings revealed that the ductility of the treated samples increases with the increase in WPF addition, while the highest UCS is found with a small fiber addition. The results of CaCO3 content suggest that the WPF addition enhances the immobilization of the bacteria cells, thus yielding the precipitation content. However, shear wave velocity analysis indicates that a higher addition of WPF results in rapid deterioration of the samples when subjected to freeze–thaw cycles. Microscale analysis illuminates that fiber clusters replace the solid bonding at particle contacts, leading to reduced resistance to freeze–thaw damage. Overall, the study demonstrates that as a waste material, WPF could be sustainably reused in the bio-cementation.

2013 ◽  
Vol 723 ◽  
pp. 353-360
Author(s):  
Li Bo Gao ◽  
Xing Hua Fan ◽  
Ming Gao ◽  
Feng Cheng Wang

This paper has studied the mechanical properties (freeze-thaw splitting strength, and dynamic modulus) and road performance (dynamic creep and fatigue life) of the asphalt mixture under the freeze-thaw circle test, and made the quantitative analysis of the influence on the material performance under freeze-thaw circle test.


2018 ◽  
Vol 46 (6) ◽  
pp. 20160145 ◽  
Author(s):  
WenJie Ge ◽  
Chen Cai ◽  
Xiang Ji ◽  
Ashraf F. Ashour ◽  
DaFu Cao

2016 ◽  
Vol 9 (1) ◽  
pp. 59-61
Author(s):  
MNH Khan ◽  
S Kawasaki ◽  
MR Hassan

Bio-cementation is a sand consolidation technology, in which ureolytic bacteria release carbonate from urea hydrolysis in the presence of an excess of calcium ions to form calcite (CaCO3) in-situ. Biocementation is to enhance the strength and stiffness properties of soil and rocks though microbial activity or products. This paper addressed the prospect of microbial carbonate precipitation for erosion control in Bangladesh. Bacterial CaCO3 precipitation under appropriate conditions is a general phenomenon where the ureolytic bacteria uses urea as an energy source and produces ammonia which increases the pH in the environment and generates carbonate, causing Ca2+ and CO32- to be precipitated as CaCO3. This CaCO3 join sand particles and forms rocklike materials that auto-repairs by means of sunlight, seawater, and bacteria as microbially induced carbonate precipitation method. These rock particles when produced artificially is called artificial rock and has the potentiality to protect coastlines from erosion.J. Environ. Sci. & Natural Resources, 9(1): 59-61 2016


2014 ◽  
Vol 912-914 ◽  
pp. 131-135
Author(s):  
Xiang Ping Fu ◽  
Xiao Xue Liu ◽  
Yi Ze Sun ◽  
Pei Huang ◽  
Yu Chen Li ◽  
...  

The experiment studies how the freeze-thaw cycles influence concrete compressive strength and elasticity modulus with different water-cement ratio under the air-entraining agent and zero of that value respectively. It can be found that modulus of elasticity and compressive strength of the concrete specimen reduced significantly when there is air-entraining agent; the durability of freeze-thaw resistance, however, makes great improvement; as the cement increases, both of them improves effectively. Through the comparison of concrete compressive strength and elastic modulus with different water-cement ratio and air-entraining agent, the optimal water-cement ratio and air-entraining agent were determined. The results of experiment can be used in concrete engineering design in severe cold area.


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