scholarly journals Study on Strength Behavior of Organic Soil Stabilized with Fly Ash

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Bayshakhi Deb Nath ◽  
Md. Keramat Ali Molla ◽  
Grytan Sarkar
Keyword(s):  
Fly Ash ◽  
Organic Soil ◽  
Pozzolanic Reaction ◽  
Organic Content ◽  
Ash Content ◽  
Dry Density ◽  
Type I ◽  
Type Ii ◽  
Acidic Properties ◽  
Strength Behavior

The aim of this study is to investigate the effect of fly ash on the consistency, compactness, acidic properties, and strength of organic soil. The presence of organic content in the soil has detrimental impacts on the physical and strength behavior of soil. To investigate the effectiveness of fly ash in the stabilization of organic soil, two types of fly ashes (Type I and Type II) at different percentages were used. It is found that fly ash significantly reduces the plasticity index of the organic soil, whereas the liquid and plastic limits increase. The dry density of the fly ash-soil mixture increases significantly, while the water requirement reduces due to the addition of fly ash. The increase of dry density compromises higher strength. The increase of qu with the increase of fly ash content is mainly due to the pozzolanic reaction of fly ash, although the reduction in water content results from the addition of dry fly ash solid. Moreover, Type I fly ash contributes a higher value of qu compared to Type II fly ash. This is attributed to the characteristics of fly ash including CaO and CaO/SiO2 ratio.

Effect of Fly Ash Incorporation on Rheology of Cement Pastes

1986 ◽  
Vol 86 ◽  
Author(s):  
M. Rattanussorn ◽  
D. M. Roy ◽  
R. I. A. Malek
Keyword(s):  
Fly Ash ◽  
Chemical Composition ◽  
Zeta Potential ◽  
Spherical Shape ◽  
Ash Content ◽  
Type I ◽  
Special Effect ◽  
Cement Pastes ◽  
Cement Ratio ◽  
Water To Cement Ratio

ABSTRACTThe predominant spherical shape of fly ash particles combined with mainly glassy composition and texture of its surfaces have a special effect on rheology of cement pastes containing fly ash. The early ages rheological behavior of cement pastes (ASTM Type I) incorporating 30% low-calcium fly ash was monitored by measuring viscosity of the fresh pastes prior to initial hardening and stiffening (up to −2 hours) as a function of time. The viscosities were determined using a co-axial rotoviscometer (HAAKE). The effects of fly ash content, water to cement ratio, and presence and concentration of superplasticizer, were evaluated. In addition, the dispersivity of fly ash spheres was evaluated by determining the zeta-potential of fly ash suspensions in water using a microelectrophoresis technique and the results were correlated to the chemical composition of fly ash as well as the viscosities of fresh pastes.

scholarly journals Experiments on Foamed Concrete for the Development of Building Blocks

2020 ◽  
Vol 8 (5) ◽  
pp. 2824-2829
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Building Blocks ◽  
Ash Content ◽  
Partial Replacement ◽  
Dry Density ◽  
Load Bearing ◽  
Concrete Building ◽  
Concrete Blocks ◽  
Foamed Concrete

Foamed concrete is an innovative and versatile lightweight building material, which is a cement-based mortar consisting of at least 20% of its volume filled with air. Use of lightweight foamed concrete blocks with densities less than 1800 kg/m3 as infills will lead to the design of slender sections. Further, the thermal insulation properties of foamed concrete blocks made it more popular in construction industry. This paper discusses the development of foamed concrete building blocks for load bearing and non-load bearing structures. To make the mix more sustainable, the feasibility of fly ash as a partial replacement to cement is also explored. The variables considered for the production of foamed concrete are foam volume, water/powder (mix of cement and fly ash) ratio, fly ash content and sand/powder ratio. Analytical model is also developed for compressive strength and dry density of foamed concrete considering different variables and it is validated. Compressive strength is found to be increasing with the increase in dry density and with increase in fly ash content. Thermal conductivity is observed to be reduced by the addition of fly ash content

scholarly journals Efficacy of Class C Fly Ash as a Stabilizer for Marginal Residual Soil

2020 ◽  
Vol 5 (1) ◽  
pp. 97-104
Author(s):  
M Umar ◽  
H. M. Alhassan
Keyword(s):  
Fly Ash ◽  
Road Construction ◽  
Strength Properties ◽  
Ash Content ◽  
Engineering Properties ◽  
Dry Density ◽  
Residual Soil ◽  
Compression Tests ◽  
Two Samples ◽  
Class C

Two laterites samples known for their deficiency in road construction were used to assess the efficacy of Class C fly ash in improving their engineering properties. The two samples were taken from Danbare and Dausayi localities within Kano Metropolis and the fly ash was sourced from the Nigerian Coal Corporation, Enugu. Preliminary tests on the two samples confirmed their deficiency for use in road construction. The processed fly ash was blended with the laterite samples at 0, 3, 6, 9, 12, 15 and 18%. Hence, the treated soil samples were tested for plasticity, compaction and strength properties. Results obtained revealed reduction in plasticity properties as the fly ash contents increased. Similarly, Maximum Dry Density (MDD) decreased as the fly ash content increased while the Optimum Moisture Content (OMC) of the treated soils increased for the two samples. Peak CBR values of 16 and 35% were obtained at 9 and 15% fly ash contents for samples 1 and 2, respectively. The unconfined compression tests showed considerable improvement in strength properties higher than the values of the natural soils. The peak 7 days strength of 630 and 1410 kN/m2 were observed at 12% and 15% fly ash content for samples 1 and 2, respectively.

scholarly journals Experimental investigations for assessing the influence of fly ash on the flow through porous media in Darcy regime

2021 ◽  
Vol 83 (5) ◽  
pp. 1028-1038
Author(s):  
Abhishish Chandel ◽  
Vijay Shankar ◽  
M. A. Alam
Keyword(s):  
Porous Media ◽  
Fly Ash ◽  
Hydraulic Conductivity ◽  
Ash Content ◽  
Sand Fly ◽  
Unit Weight ◽  
Experimental Investigations ◽  
Dry Density ◽  
Empirical Equations ◽  
River Sand

Abstract Hydraulic conductivity plays a vital role in the studies encompassing explorations on flow and porous media. The study investigates the compaction characteristics of a river sand (Beas, Sutlej, and Ghaggar rivers) and fly ash mix in different proportions and evaluates four empirical equations for estimating hydraulic conductivity. Experiments show that an increase in the fly ash content results in a decrease in the maximum dry density (MDD) and an increase in the corresponding optimum moisture content (OMC) of sand–fly ash samples. MDD at optimum fly ash content was achieved at low water content, which resulted in less dry unit weight than that of typical conventional fill. In Beas, Sutlej, and Ghaggar sands the optimum fly ash content up to which the hydraulic conductivity value reduced uniformly was found to be 30, 45, and 40%, respectively. Any further increase in the fly ash content results in a negligible decrease in hydraulic conductivity value. The observed hydraulic conductivity of sand–fly ash mix lies in the range of silts, which emboldens the use of sand–fly ash mix as embankment material. Further, the evaluation of empirical equations considered in the study substantiates the efficacy of the Terzaghi equation in estimating the hydraulic conductivity of river sand-fly ash mix.

Study on the Strength Behavior of Soil with Nano Fly Ash and Nano Cement

2018 ◽  
Vol 24 (8) ◽  
pp. 5633-5635
Author(s):  
M Kirithika ◽  
V. K Stalin
Keyword(s):  
Fly Ash ◽  
Specific Surface ◽  
High Specific Surface Area ◽  
Nano Particles ◽  
Dry Density ◽  
Particle Sizes ◽  
Test Results ◽  
Software Analysis ◽  
Strength Behavior ◽  
Imagej Software

Nanotechnology is the science that deals with the particles which are less than 100 nm. The size of the nanoparticles plays a crucial role in behavior of soil exhibiting different properties. Use of nanoparticles in stabilization influences shear strength, dry density of the soil and makes more reactive to soil because of its high specific surface area. In this investigation, an attempt is made to investigate the influence of ball milled nano fly ash and nano cement particles in the improvement of soil. Different combinations of percentage were selected in the range of non-nano fly ash (10%, 20% and 30%) and non-nano Cement (2%, 6%, 8% and 10%). Preparation of nanoparticles has done by planetary ball milling. Particle sizes of the additives were obtained by HRTEM test results and IMAGEJ software analysis. Nano fly ash and Nano cement were admixed with soil for the optimum mix of 10% fly ash and 10% cement. Results indicated that compare to non-nano particles in soil, the nano admixed soil yielded UCC strength of 1416 kN/m2 which is 1.2 times higher than non-nanoparticles. The higher strength of nanoparticles admixed soil is mainly due to higher reactivity of nano fly ash and nano cement with the soil because of the enhanced specific surface.

scholarly journals Experimental Research on Microstructure and Physical-Mechanical Properties of Expansive Soil Stabilized with Fly Ash, Sand, and Basalt Fiber

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Qin-yong Ma ◽  
Zi-ming Cao ◽  
Pu Yuan
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Basalt Fiber ◽  
Expansive Soil ◽  
Optimum Moisture Content ◽  
Ash Content ◽  
Dry Density ◽  
Sand Content ◽  
Maximum Dry Density ◽  
Stabilized Soil

Expansive soil is a source of risk to the foundations or subgrade engineering. Stabilization of expansive soil is imperative for practical engineering. A series of laboratory experiments were performed to analyze the physical-mechanical properties and microstructures of stabilized soil. Three stabilizers used in this study are fly ash, sand, and basalt fiber. Different percentages of fly ash (0, 5, 10, 15, and 20%), sand (0, 8, 16, and 24%), and basalt fiber (0 and 0.4%) were added by weight into natural soil. Experimental results indicate that the optimum moisture content of stabilized soil increases with the increase of fly ash content for a given sand content, whereas the maximum dry density shows a decreasing trend. The variation trend of optimum moisture content and maximum dry density turns reverse with the increase of sand content for a given fly ash content. Plasticity index is decreased by both increasing fly ash content and sand content. It is found that the maximum unconfined compressive strength and optimum growth rate of strength are obtained by selected mixtures of 10% fly ash, 8% sand, and 0.4% basalt fiber contents. As the analysis of complementary effect suggests, most of the mixt treatments applied in this study have produced good results associated with the strength enhancement of expansive soil. In line with the results of SEM tests, the connection among clay particles has been enhanced through the generation of hydration products (C-S-H and AFt) of fly ash. The filling effect of sand has increased the integrality and compactness of stabilized soil. Moreover, the gripping effect between fibers and soil particles notably improves the strength of stabilized soil. The effect of sand on reinforced soil with 0.4% basalt fiber increases the interfacial force between fibers and soil particles.

Stabilization of Artificial Organic Soil at Room Temperature Using Blended Lime Zeolite

2013 ◽  
Vol 723 ◽  
pp. 985-992 ◽  
Author(s):  
Felix Ngee Leh Ling ◽  
Khairul Anuar Kassim ◽  
Ahmad Tarmizi Abdul Karim ◽  
Tze Wei Chan
Keyword(s):  
Room Temperature ◽  
Organic Soil ◽  
Pozzolanic Reaction ◽  
Organic Content ◽  
Organic Soils ◽  
Zeolite A ◽  
Reaction Products ◽  
Lime Stabilization ◽  
Curing Period ◽  
Strength Increment

Organic content in soil is believed to inhibit formation of reaction products in lime stabilization which resulted in low gain of strength when dealing with organic soils. Zeolite, a kind of pozzolan with high CEC capacity is proposed to be use in this study in order to improve lime stabilization of organic soil. The effectiveness of blended lime zeolite in stabilization of organic soils was investigated by using two types of artificial organic soils with predetermined organic contents. Artificial organic soils were formed by mixing inorganic soil (commercial kaolin) with organic matter (commercial humic acid) at specific ratio. Initial consumption of lime for organic soils was determined in order to determine the minimum percentage of stabilizer required for each soil. Potential influencing factors that might affect the strength such as organic contents, contents of stabilizer, and curing periods were studied. The findings of the study showed that high organic contents and low lime contents resulted in lower gain of strength. However, it is found that slight replacement of lime with zeolite works well with low organic soil at long curing period which resulted in highest strength among all the mixes. Overall, longer curing periods will increase the strength of the soil in the order of 56 days > 28 days > 7 days. Nevertheless, the percentage of strength increment over curing periods is linear with the lime contents, which proved that lime is required for pozzolanic reaction.

scholarly journals Optimization of Soil to Fly-Ash Mix Ratio for Enhanced Engineering Properties of Clayey Sand for Subgrade Use

2020 ◽  
Vol 10 (20) ◽  
pp. 7038
Author(s):  
M. A. Karim ◽  
Ahmed Sami Hassan ◽  
Adam Kaplan
Keyword(s):  
Fly Ash ◽  
Volume Change ◽  
Ash Content ◽  
Engineering Properties ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Clayey Sand ◽  
Curing Period ◽  
Change Behavior ◽  
Volume Change Behavior

A laboratory investigation was carried out to determine the optimum soil to fly ash mix ratio to enhance the engineering properties of clayey sand that can potentially be used as a road subgrade. Grain size distribution and Atterberg limits tests were conducted to classify the soil and to study the effects of the fly ash on the soil plasticity. The Proctor test was conducted to determine the optimum moisture content and maximum dry density of soil-fly-ash mixtures with arbitrarily selected 0%, 40%, 50%, and 60% fly ash content. A higher percentage was selected to find the highest optimum fly ash content to maximize the beneficial use. Unconfined compression and consolidation tests were conducted with air-dry arbitrarily selected curing periods of 0, 2, 8, and 28 days to determine the strength and to predict the settlement and the volume change behavior. It can be concluded from the trend analysis that a fly ash content range of 32–50% appeared to be optimum that is expected to perform better as subgrade materials for a curing period range of 16–19 days. However, experimental data showed a fly ash content of 50% was the optimum for a curing period of 8 days. The settlement and the volume change behavior improved at least 44% with increased fly ash content.

scholarly journals Utilisation of CFBC Fly Ash in Hardening Slurries for Flood-Protecting Dikes

2016 ◽  
Vol 62 (3) ◽  
pp. 75-88
Author(s):  
Z. Kledyński ◽  
P. Falaciński ◽  
A. Machowska ◽  
J. Dyczek ◽  
Ł. Kotwica
Keyword(s):  
Fly Ash ◽  
Hydraulic Conductivity ◽  
Mechanical Strength ◽  
Microstructural Evolution ◽  
Brown Coal ◽  
Type I ◽  
Type Ii ◽  
Cfbc Fly Ash

Abstract Strength and permeability properties along with microstructural evolution of hardened slurries composed of fly ash from fluidal bed combustion of brown coal and an addition of OPC/BFSC is assessed in this paper. An increase in the amount of fly ash in slurries influences the development of mechanical strength and a decrease of hydraulic conductivity. SEM, XRD, and porosity analyses confirmed formation of watertight microstructures. The structure of slurries is composed of ettringite, C-S-H phase, AFt, and AFm phases. Ettringite crystallises as relatively short needles forming compact clusters or intermixed with the C-S-H phase. The occurring C-S-H phases are mainly of type I - fibrous and type II - honeycomb.

Sign in / Sign up

Export Citation Format

Share Document