scholarly journals The Mechanical Properties of Fly-Ash-Stabilized Sands

Geosciences ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 132 ◽  
Author(s):  
Minson Simatupang ◽  
Lukas Kano Mangalla ◽  
Romy Suryaningrat Edwin ◽  
Adris Ade Putra ◽  
Muhammad Thahir Azikin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Fly Ash ◽  
Sample Preparation ◽  
Degree Of Saturation ◽  
Direct Shear ◽  
Curing Time ◽  
Grain Sizes ◽  
Strength Tests ◽  
Strength And Stiffness

The stabilization of soil through the addition of fly ash has been shown to be an effective alternative for improving the strength and stiffness of soil through the resulting chemical reactions. The chemical reaction that occurs dissociates the lime (CaO) in the fly ash, and the establishment of cementitious and pozzolanic gels (consisting of calcium silicate hydrate (CSH) gel and calcium aluminate hydrate (CAH) gel) binds the soil particles and increases the strength and stiffness of the soil. Investigations into the mechanical properties of sands stabilized with fly ash (fly-ash-stabilized sands) were conducted through a series of unconfined compressive strength (UCS) and direct shear strength tests for various fly ash percentages, curing times, grain sizes, degrees of saturation during sample preparation, and content of fines. It was found that the mechanical properties—UCS and direct shear strength (DSS)—of fly-ash-stabilized sands increased with both increasing fly ash content in the specimen and curing time, but decreased with increasing grain size, degree of saturation during sample preparation, and content of fines. The results indicated that fly-ash-stabilized sands required more than a month to attain their optimum performance with regard to binding sand particles.

scholarly journals Strength Tests and Numerical Simulations of Loess Modified by Desulfurization Ash and Fly Ash

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 512
Author(s):  
Zhi Cheng ◽  
Xinrong Cheng ◽  
Yuchao Xie ◽  
Zhe Ma ◽  
Yuhao Liu
Keyword(s):  
Shear Strength ◽  
Fly Ash ◽  
Power Plants ◽  
Utilization Rate ◽  
Direct Shear ◽  
Test Results ◽  
Mass Ratio ◽  
Direct Shear Tests ◽  
Strength Tests ◽  
Actual Test

Desulfurization ash and fly ash are solid wastes discharged from boilers of power plants. Their utilization rate is low, especially desulfurization ash, most of which is stored. In order to realize their resource utilization, they are used to modify loess in this paper. Nine group compaction tests and 32 group direct shear tests are done in order to explore the influence law of desulfurization ash and fly ash on the strength of the loess. Meanwhile, FLAC3D software is used to numerically simulate the direct shear test, and the simulation results and the test results are compared and analyzed. The results show that, with the increase of desulfurization ash’s amount, the shear strength of the modified loess increases first and then decreases. The loess modified by the fly ash has the same law with that of the desulfurization ash. The best mass ratio of modified loess is 80:20. When the mass ratio is 80:20, the shear strength of loess modified by the desulfurization ash is 12.74% higher than that of the pure loess on average and the shear strength of loess modified by fly ash is 3.59% higher than that of the pure loess on average. The effect of the desulfurization ash on modifying the loess is better than that of the fly ash. When the mass ratio is 80:20, the shear strength of loess modified by the desulfurization ash is 9.15% higher than that of the fly ash on average. Comparing the results of the simulation calculation with the actual test results, the increase rate of the shear stress of the FLAC3D simulation is larger than that of the actual test, and the simulated shear strength is about 8.21% higher than the test shear strength.

Research about the Effect of Polypropylene Fiber on Mechanical Properties of Curing Sludge

2011 ◽  
Vol 250-253 ◽  
pp. 788-794
Author(s):  
Shu Lin Zhan ◽  
Shu Sen Gao ◽  
Jun Ying Lai
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Shear Strength ◽  
Water Content ◽  
Unconfined Compressive Strength ◽  
Polypropylene Fiber ◽  
Physical And Mechanical Properties ◽  
Curing Time ◽  
Strength Tests ◽  
Different Content

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.

scholarly journals Studies on the Volumetric Stability and Mechanical Properties of Cement-Fly-Ash-Stabilized Steel Slag

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 495
Author(s):  
Mingkai Zhou ◽  
Xu Cheng ◽  
Xiao Chen
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Steel Slag ◽  
Critical Issue ◽  
Expansion Behavior ◽  
Strength Tests ◽  
Road Materials ◽  
Base Course ◽  
The Stability ◽  
Aggregate Base

The stability of steel-slag road materials remains a critical issue in their utilization as an aggregate base course. In this pursuit, the present study was envisaged to investigate the effects of fly ash on the mechanical properties and expansion behavior of cement-fly-ash-stabilized steel slag. Strength tests and expansion tests of the cement-fly-ash-stabilized steel slag with varying additions of fly ash were carried out. The results indicate that the cement-fly-ash-stabilized steel slag exhibited good mechanical properties. The expansion rate and the number of bulges of the stabilized material reduced with an increase in the addition. When the addition of fly ash was 30–60%, the stabilized material was not damaged due to expansion. Furthermore, the results of X-CT, XRD and SEM-EDS show that fly ash reacted with the expansive component of the steel slag. In addition, the macro structure of the stabilized material was found to be changed by an increase in the concentration of the fly ash, in order to improve the volumetric stability. Our study shows that the cement-fly-ash-stabilized steel slag exhibits good mechanical properties and volumetric stability with reasonable additions of fly ash.

The Research on the Mechanical Properties of the same Curing Agent of Different Soil Dredged Mud

2013 ◽  
Vol 800 ◽  
pp. 181-188
Author(s):  
Xiao Yan Yang ◽  
Wen Bai Liu ◽  
Jia Jun Wang ◽  
Wen Hui Shi
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Compression Test ◽  
Direct Shear Test ◽  
Shear Test ◽  
Silty Sand ◽  
Curing Agent ◽  
Direct Shear ◽  
Confined Compression ◽  
Silty Soil

Through confined compression test and direct shear test, studied the mechanical properties of the same curing agent of different soil dredged mud, compared the difference of the same curing agent of different soil dredged mud. By confined compression test, the compression modulus of clay, silty sand and silty soil dredged mud after curing increases by 603.7%, 529.0% , 603.7% respectively. By direct shear test, the shear strength of clay dredged mud after curing increases to infinity; silty sands shear strength after curing increases by 209.1% in average; silty soils shear strength increases after curing by 147.5% in average. The compression and shear resistance of this kind of special curing agent for clay is best, silty sand second, but for the silty soil only has a little effect.

Mechanical Properties of Fly Ash-Slag-Dredged Silt System Stimulated by Alkali

2013 ◽  
Vol 807-809 ◽  
pp. 1140-1146 ◽  
Author(s):  
Yi Xuan Chen ◽  
Xiu Li Sun ◽  
Zhi Hua Li
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Fly Ash ◽  
Construction Materials ◽  
Xrd Analysis ◽  
Test Results ◽  
X Ray Diffraction ◽  
Shear Tests ◽  
X Ray ◽  
Direct Shear Tests

The objective of this work is to investigate the stimulation effect of the addition of alkali on the fly ash and slag for stabilizing dredged silt. Based on the test results, a viable alternative for the final disposal of dredged silt as subgrade construction materials were proposed. For this purpose, several mixtures of dredged silt-fly ash-slag and alkali were prepared and stabilized/solidified. In this system, fly ash and slag were used as hardening agents (solidified materials) of dredged silt and alkali was used as activator of fly ash and slag. The shear strength of the mixture was tested by several direct shear tests. Furthermore, X-Ray Diffraction (XRD) analysis was used to determine the hydration products of the system. The specimens were tested in order to determine the shear strength changes versus hydration time and the alkali content. It is indicated that mechanical properties of solidified silt are improved significantly by addition of fly ash and slag stimulated by alkali.

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