Effect of humic acid on the behaviour of solidified dredged material

2009 ◽  
Vol 46 (9) ◽  
pp. 1093-1099 ◽  
Author(s):  
Wei Zhu ◽  
C. F. Chiu ◽  
Chun-Lei Zhang ◽  
Ke-Lin Zeng

Unconfined compression and bound-water content tests were conducted to study the effect of humic acid on the mechanical behaviour of solidified dredged material. It is found that the unconfined compressive strength (qu) and the change in bound-water content (Δmbw) exhibit similar relationships with the humic-acid content and curing time. Both parameters decrease with an increase in humic-acid content until reaching a threshold humic-acid content, above which the magnitudes of both parameters reduce to relatively low and steady values. In addition, both qu and Δmbw increase nonlinearly with the curing time. A relationship between qu and Δmbw is presented; Δmbw may reflect the extent of the hydrates developed in the solidified soil which increases nonlinearly with qu.

2011 ◽  
Vol 250-253 ◽  
pp. 788-794
Author(s):  
Shu Lin Zhan ◽  
Shu Sen Gao ◽  
Jun Ying Lai

In order to study the influence of modified polypropylene (PP) fiber on the physical and mechanical properties of curing sludge, the same amount of cement and different content of polypropylene fiber were mixed into the sludge. Unconfined compressive strength tests, water content tests and shear strength tests were carried out on different specimens with different curing time. The results show that the sludge curing effect is markedly improved by the addition of the polypropylene fiber. As to the curing sludge with the same curing time, when the content of the polypropylene fiber increases, the unconfined compressive strength and the cohesive strength greatly increase, and the internal frictional angle decreases.


Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6273
Author(s):  
Chunping Gu ◽  
Jikai Yao ◽  
Yang Yang ◽  
Jie Huang ◽  
Linhao Ma ◽  
...  

Fly ash (FA) has been widely used in cement-based materials, but limited work has been conducted to establish the relationship between the compressive strength and hydration process of high-volume FA (HVFA)-cement-based material. In this study, the compressive strength and chemically bound water contents of FA-cement-based materials with different water-to-binder ratios (0.4, 0.5, and 0.6) and FA contents (0%, 30%, 40%, 50%, 60%, and 70%) were tested. Replacing more cement with FA reduced the compressive strength and of HVFA-cement-based materials. The compressive strength and chemically bound water content reduced by about 60–70% when 70% cement was replaced by FA. Water-to-binder ratio showed more significant influence on the chemically bonded water at later ages than that at early ages. Based on test results, the prediction equation of chemically bound water content was established, and its accuracy was verified. The error was less than 10%. The relationship between the compressive strength and chemically bound water content was also fitted. The compressive strength and chemically bound water content showed linear relationships for different water-to-binder ratios, hence the compressive strength of HVFA-cement mortar could be predicted with the chemically bound water content and water-to-binder ratios. The results of this study could be used for the prediction of the compressive strength development of HVFA-cement mortars, and is helpful to develop the mix design method of HVFA-cement-based materials.


2012 ◽  
Vol 268-270 ◽  
pp. 642-645 ◽  
Author(s):  
Ying Di Liao ◽  
Chao Hua Jiang ◽  
Xing Guo Feng

Different cement types were used to stabilize coastal soft soil. The unconfined compression strength of each cement type treated soil was tested at different curing time. The results showed that the higher strength degree cement lead to the higher unconfined compression strength with same cement addition after curing 90 days. An empirical correlation between unconfined compressive strength and curing time was presented to forecast the unconfined compression strength of cement-soil. Additionally, the 14 day and the data of unconfined compressive strength at that time were suggested to use as the basic standard time and standard strength data respectively.


1996 ◽  
Vol 34 (3-4) ◽  
pp. 443-448 ◽  
Author(s):  
G. W. Chen ◽  
W. W. Lin ◽  
D. J. Lee

The feasibility of employment of capillary suction time (CST) for characterizing the dewaterability of excess activated sludges was examined. The CST was shown as a good index for sludge filterability, if only the product of solid concentration and average specific resistance is of interest. On the other hand, the bound water content cannot be directly evaluated from the CST data.


2005 ◽  
Vol 3 (2) ◽  
pp. 116-126 ◽  
Author(s):  
Woo‐Sik Kim ◽  
Nguyen Minh Tam ◽  
Du‐Hwoe Jung

This paper describes the effect of factors on the strength characteristics of cement treated clay from laboratory tests performed on cement mixed clay specimens. It is considered that several factors such as soil type, sample preparing method, quantity of binder, curing time, etc. can have an effect on strength characteristics of cement stabilized clay. A series of unconfined compression tests have been performed on samples prepared with different conditions. The results indicated that soil type, mixing method, curing time, dry weight ratio of cement to clay (Aw), and water‐clay to cement (wc/c) ratio were main factors which can have an influence on unconfined compressive strength, modulus of elasticity, and failure strain of cement stabilized clay. Unconfined compressive strength of soil‐cement samples prepared from dry mixing method was higher than those prepared from wet mixing method.


1938 ◽  
Vol 36 (1) ◽  
pp. 99-105 ◽  
Author(s):  
C. A. Friedman ◽  
B. S. Henry

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