Experimental Study on the Stabilization Effects of Dredged Sludge by Fly Ash or Phosphogypsum

2013 ◽  
Vol 689 ◽  
pp. 342-347 ◽  
Author(s):  
Zhi Hua Yu ◽  
Yue Gui ◽  
Qing Zhang ◽  
Xiang Yun Kong
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Liquid Limit ◽  
Industrial Wastes ◽  
Plastic Limit ◽  
Dredged Sludge ◽  
Ratio Limit ◽  
Optimal Effect ◽  
Curing Age

It is very essential to explore a more efficient and a lower-cost stabilizer based the traditional stabilizer, lime. Through the laboratory test, this article made a comparison on the stabilization effects from the water ratio limit and unconfined compressive strength of the stabilized sludge, which was processed by using two common industrial wastes as stabilizers, fly ash and phosphogypsum, with the lime. The laboratory experiment results indicate that liquid limit and plastic limit of phosphogypsum compound stabilizers have a significant increase compared with the single lime added solidified sludge, but little change in the plasticity index over a curing age of 7 days or 28 days; while that of by adding fly ash has almost no change in liquid limit and plastic limit compared with the single lime added solidified sludge. Meanwhile the solidified sludge by adding the previous two stabilizers have an increase in unconfined compressive strength compared with the single lime added solidified sludge. Comprehensively compared above, the waste phosphogypsum as the extra additive stabilizer of the lime makes the optimal effect.

Experimental Study on the Performance of Compound Improved HLLS (High Liquid Limit Soil) with Various Curing Agents

2017 ◽  
Vol 753 ◽  
pp. 300-304 ◽  
Author(s):  
Yun Que ◽  
Yi Qian Lin ◽  
Fang Ze Gong
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Cement Content ◽  
Liquid Limit ◽  
Curing Agent ◽  
Compressive Strength Test ◽  
Curing Agents ◽  
The One ◽  
Better Than ◽  
Curing Age

The HLLS (high liquid limit soil) has the characteristics of high moisture content, low bearing capacity and poor water stability. Most of the existing treatment methods focus on the improvement with a single curing agent, and the research on the improvement of HLLS with various curing agents is still insufficient. This paper presents the characteristics of two kinds of compound improved HLLS based on unconfined compressive strength test. The results show that the unconfined compressive strength of CSIS (Cement / SAP Improved Soil) and CLIS (Cement / Renolith Improved Soil) are greatly improved than those of CIS (Cement Improved Soil) when the curing age is 28d, respectively. The maximum increments of unconfined compressive strength are 0.31MPa and 0.22MPa, respectively. When the cement content is less (more) than 3%, the unconfined compressive strength of CSIS decreases (increases) with the increase of SAP content. When the cement content is constant, the unconfined compressive strength of CLIS increases first and then decreases with the increase of the Renolith content. The optimum mix amount of SAP (Renolith) and cement in CSIS (CLIS) are 0.06% (0.2%) and 5% (3%), respectively. The strength and crack resistance of the two kinds of compound improved soil are better than the one with single curing agent. SAP and Renolith exert the properties of self-curing after water absorption and hydrophobicity, respectively.

scholarly journals Soil Unconfined Compressive Strength Prediction Using Random Forest (RF) Machine Learning Model

2020 ◽  
Vol 14 (1) ◽  
pp. 278-285
Author(s):  
Hai-Bang Ly ◽  
Binh Thai Pham
Keyword(s):  
Machine Learning ◽  
Compressive Strength ◽  
Random Forest ◽  
Specific Gravity ◽  
Moisture Content ◽  
Unconfined Compressive Strength ◽  
Void Ratio ◽  
Clay Content ◽  
Liquid Limit ◽  
Plastic Limit

Aims: Understanding the mechanical performance and applicability of soils is crucial in geotechnical engineering applications. This study investigated the possibility of application of the Random Forest (RF) algorithm – a popular machine learning method to predict the soil unconfined compressive strength (UCS), which is one of the most important mechanical properties of soils. Methods: A total number of 118 samples collected and their tests derived from the laboratorial experiments carried out under the Long Phu 1 power plant project, Vietnam. Data used for modeling includes clay content, moisture content, specific gravity, void ratio, liquid limit and plastic limit as input variables, whereas the target is the UCS. Several assessment criteria were used for evaluating the RF model, namely the correlation coefficient (R), root mean squared error (RMSE) and mean absolute error (MAE). Results: The results showed that RF exhibited a strong capability to predict the UCS, with the R value of 0.914 and 0.848 for the training and testing datasets, respectively. Finally, a sensitivity analysis was conducted to reveal the importance of input parameters to the prediction of UCS using RF. The specific gravity was found as the most affecting variable, following by clay content, liquid limit, plastic limit, moisture content and void ratio. Conclusion: This study might help in the accurate and quick prediction of the UCS for practice purpose.

scholarly journals Characterization and Comparison Research on Composite of Alluvial Clayey Soil Modified with Fine Aggregates of Construction Waste and Fly Ash

2021 ◽  
Vol 28 (1) ◽  
pp. 83-95
Author(s):  
Qu Jili ◽  
Wang Junfeng ◽  
Batugin Andrian ◽  
Zhu Hao
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Clayey Soil ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Construction Waste ◽  
Comparison Research ◽  
Fine Aggregates ◽  
Optimum Water Content

Abstract Fine aggregates of construction waste and fly ash were selected as additives to modify the characteristics of Shanghai clayey soil as a composite. The laboratory tests on consistency index, maximum dry density, and unconfined compressive strength were carried out mainly for the purpose of comparing the modifying effect on the composite from fine aggregates of construction waste with that from fly ash. It is mainly concluded from test results that the liquid and plastic limit of the composites increase with the content of two additives. But their maximum dry density all decreases with the additive content. However, fine aggregates of construction waste can increase the optimum water content of the composites, while fly ash on the contrary. Finally, although the two additive all can increase the unconfined compressive strength of composites, fly ash has better effect. The current conclusions are also compared with previous studies, which indicates that the current research results are not completely the same as those from other researchers.

Development of Geopolymer Mortar from Metakaolin Blended with Agricultural and Industrial Wastes

2018 ◽  
Vol 766 ◽  
pp. 305-310 ◽  
Author(s):  
Chayanee Tippayasam ◽  
Sarochapat Sutikulsombat ◽  
Jamjuree Paramee ◽  
Cristina Leonelli ◽  
Duangrudee Chaysuwan
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Chemical Properties ◽  
Cement Industry ◽  
Industrial Wastes ◽  
Engineering Properties ◽  
Alkali Solutions ◽  
Physical And Chemical

Geopolymer is a greener alternative cement produced from the reaction of pozzolans and strong alkali solutions. Generally, the cement industry is one of largest producers of CO2that caused global warming. For geopolymer mortar usage, Portland cement is not utilized at all. In this research, geopolymer mortars were prepared by mixing metakaolin, various wastes (fly ash, bagasse ash and rice husk ash) varied as 80:20, 50:50 and 20:80, 15M NaOH, Na2SiO3and sand. The influence of various parameters such as metakaolin to ashes ratios and pozzolans to alkali ratios on engineering properties of metakaolin blended wastes geopolymer mortar were studied. Compressive strength tests were carried out on 25 x 25 x 25 mm3cube geopolymer mortar specimens at 7, 14, 21, 28 and 91 air curing days. Physical and chemical properties were also investigated at the same times. The test results revealed that the highest compressive strength was 20% metakaolin - 80% fly ash geopolymer mortar. When the curing times increases, the compressive strength of geopolymer mortar also increases. The mixing of metakaolin and bagasse ash/rice husk ash presented lower compressive strength but higher water absorption and porosity. For FTIR results, Si-O, Al-O and Si-O-Na+were found. Moreover, the geopolymer mortar could easily plastered on the wall.

Size Effect on Compressive Strength and Modulus of Elasticity in High Performance Concrete

2013 ◽  
Vol 634-638 ◽  
pp. 2742-2745 ◽  
Author(s):  
Jeong Eun Kim ◽  
Wan Shin Park ◽  
Nam Yong Eom ◽  
Do Gyeum Kim ◽  
Jea Myoung Noh
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Size Effect ◽  
Modulus Of Elasticity ◽  
High Performance ◽  
High Performance Concrete ◽  
Type A ◽  
Type B ◽  
Replacement Ratio ◽  
Curing Age

This study undertook the research of size effect on compressive strength and modulus of elasticity, respectively. The parameters of this study are curing age and fly ash replacement ratio to investigate size effect of Type A (100mm x 200mm) and Type B (150mm x 300mm) specimens in high performance concrete. On this study, high performance concrete was fabricated with different FA contents of 10%, 20% and 30%. The measurements were performed on days 28 and 91.

The effects of marble dust and fly ash on clay soil

2014 ◽  
Vol 21 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Ismail Zorluer ◽  
Suleyman Gucek
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Unconfined Compressive Strength ◽  
Soil Stabilization ◽  
Clay Soil ◽  
Waste Materials ◽  
Curing Time ◽  
Freeze Thaw ◽  
Marble Dust ◽  
Increased Strength

AbstractThe use of waste materials as an additive in soil stabilization has been widespread. This is important in terms of recycling of waste materials and reducing environmental pollution. The objective of this study is to investigate the beneficial reuse of marble dust and fly ash in soil stabilization. Tests were performed on clay soil mixtures amended with marble dust and fly ash. Marble dust was used as an activator due to fly ash being inadequate for self-cementing. Unconfined compressive strength (qu), freeze-thaw, swelling, and California bearing ratio (CBR) tests were conducted to investigate the effect of marble dust and fly ash, curing time, and molding water content on geotechnical parameters. Addition of marble dust and fly ash increased unconfined compressive strength, CBR, and freeze-thaw strength, but these additives decreased swelling potential and grain loss after freeze-thaw. Increasing the curing time results in increased strength of mixtures and decreased grain loss. As a result, this study shows that the geotechnical properties of clay soil are improved with the addition of marble dust and fly ash. This is an economical and environmentally friendly solution.

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