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

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.

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Development of calibration algorithms for selected water content reflectometry probes for burned and non-burned organic soils of Alaska

International Journal of Wildland Fire ◽

10.1071/wf07175 ◽

2010 ◽

Vol 19 (7) ◽

pp. 961 ◽

Cited By ~ 8

Author(s):

Laura L. Bourgeau-Chavez ◽

Gordon C. Garwood ◽

Kevin Riordan ◽

Benjamin W. Koziol ◽

James Slawski

Keyword(s):

Soil Moisture ◽

Moisture Content ◽

Water Content ◽

Soil Profile ◽

Soil Moisture Content ◽

Mineral Soil ◽

Organic Soil ◽

Organic Content ◽

Organic Soils ◽

Probe Type

Water content reflectometry is a method used by many commercial manufacturers of affordable sensors to electronically estimate soil moisture content. Field‐deployable and handheld water content reflectometry probes were used in a variety of organic soil‐profile types in Alaska. These probes were calibrated using 65 organic soil samples harvested from these burned and unburned, primarily moss‐dominated sites in the boreal forest. Probe output was compared with gravimetrically measured volumetric moisture content, to produce calibration algorithms for surface‐down‐inserted handheld probes in specific soil‐profile types, as well as field‐deployable horizontally inserted probes in specific organic soil horizons. General organic algorithms for each probe type were also developed. Calibrations are statistically compared to determine their suitability. The resulting calibrations showed good agreement with in situ validation and varied from the default mineral‐soil‐based calibrations by 20% or more. These results are of particular interest to researchers measuring soil moisture content with water content reflectometry probes in soils with high organic content.

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Strength characteristics of artificial organic soils stabilized with copolymer stabilizer

MATEC Web of Conferences ◽

10.1051/matecconf/201816901010 ◽

2018 ◽

Vol 169 ◽

pp. 01010 ◽

Cited By ~ 1

Author(s):

Chia-Wen Law ◽

Felix Ngee-Leh Ling ◽

Boon-Khiang Ng

Keyword(s):

Organic Matter ◽

Organic Soil ◽

Organic Soils ◽

Chemical Stabilization ◽

Test Device ◽

Compressive Test ◽

Acid Ratio ◽

Strength Material ◽

Strength Increment ◽

Effective Stabilization

Organic soil is known as low strength material, and chemical stabilization is widely used to increase its bearing capacity. However, the use of traditional stabilizer has some limitations. Therefore, stabilization was carried out by using non-traditional stabilizer - Vinyl acetate-ethylene (VAE) copolymer emulsion in this study with the aim to determine its suitability to stabilize soil mixed with organic matter. Two types of artificial organic soil with kaolin: organic acid ratio of 5:5 (K5HA5) and 7:3 (K7HA3) were utilized. Control specimens were tested using pure kaolin. Different percentages of VAE (5%, 7.5%, 10%) were added in order to determine the minimum amount of stabilizer required to achieve a minimum strength increment of a 345 kPa. The strength of samples was determined with automated unconfined compressive test device. Specimens were air cured for 7 days prior to testing. Both K7HA3 with 7.5% VAE and K5HA5 with 10% VAE had achieved the minimum strength increment to be considered as effective stabilization. The strength of the artificial organic soil was found to be increasing with the increment of percentages of VAE used. Hence, it can be concluded that stabilizing mechanism of the artificial organic soils with VAE is not affected by organic matter.

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Soil moisture thresholds for combustion of organic soils in western Tasmania

International Journal of Wildland Fire ◽

10.1071/wf19196 ◽

2020 ◽

Vol 29 (7) ◽

pp. 637 ◽

Cited By ~ 1

Author(s):

Lynda D. Prior ◽

Ben J. French ◽

Kathryn Storey ◽

Grant J. Williamson ◽

David M. J. S. Bowman

Keyword(s):

Soil Moisture ◽

High Resolution ◽

Moisture Content ◽

Organic Soil ◽

Soil Bulk Density ◽

Organic Content ◽

Time Domain Reflectometry ◽

Weather Data ◽

Organic Soils ◽

Vegetation Types

The present study aimed to determine moisture thresholds for combustion of organic soils sampled from various vegetation types at 63 locations in Tasmania, Australia. To observe whether the soil sample sustained smouldering combustion, moisture content was experimentally manipulated and heat was applied. Combustion was primarily determined by moisture content, but was also influenced by soil bulk density and organic content: the gravimetric moisture content corresponding to a 50% probability of burning ranged from 25 to 94% as organic content varied from 34 to 96%. There was no evidence of differences among vegetation types in the relationship between soil combustibility and organic content. Combustion in Tasmanian organic soils occurred with moisture levels similar to those reported elsewhere, despite differences in vegetation and environment. It was also found that a hand-held meter that measured volumetric moisture content using time domain reflectometry could be used to satisfactorily predict organic soil combustion. Finally, combining the data with estimates of volumetric soil moisture based on high-resolution gridded weather data (Bureau of Meteorology Atmospheric high-resolution Regional Reanalysis for Australia, or BARRA), it was demonstrated that most Tasmanian organic soils are likely to be combustible at some time almost every summer (December to February).

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Compressive Strength and Microstructure Analysis of Treated Rice Husk Ash (TRHA) Incorporated Mortar

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i4.35.22768 ◽

2018 ◽

Vol 7 (4.35) ◽

pp. 388

Author(s):

Siti Asmahani Saad ◽

Nasir Shafiq ◽

Mariana Mohamed Osman ◽

Siti Aliyyah Masjuki

Keyword(s):

Compressive Strength ◽

Rice Husk ◽

Treatment Process ◽

Rice Husk Ash ◽

Concrete Strength ◽

Pozzolanic Reaction ◽

Cement Matrix ◽

Curing Period ◽

Strength Increment ◽

Effective Additive

High amount of reactive silica is ubiquitous in pozzolanic reaction for concrete strength increment. Rice husk ash (RHA) is proven contains high content of amorphous silica that is essential in the pozzolanic reaction of effective additive in concrete. Nevertheless, incorporation of RHA as cement replacement material (CRM) or additive is very minimal in current concrete industry. Therefore, improvement on the RHA properties by introduction of thermal and chemical pretreatment prior to incineration process is considered as a promising way in order to achieve the goal. This treatment process has been reported widely in literature. In this paper, the effect of treated rice husk ash (TRHA) and non-treated rice husk ash (NTRHA) incorporated mortar in terms of its compressive strength and microstructure properties are examine subsequently. The strength activity of TRHA from the optimum treatment process was measured by testing the compressive strength of mortars. The highest compression value obtained was 50.73MPa with 3% UFTRHA replacement at 28 days. At a longer curing period i.e. 90 days, it was recorded that 3% of UFTRHA mortar had the highest compression value at 53.87MPa. As for microstructure properties, a denser microstructure with excellent aggregate bonding and cement matrix in the interfacial transition zone (ITZ) was observed.

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Study on Strength Behavior of Organic Soil Stabilized with Fly Ash

International Scholarly Research Notices ◽

10.1155/2017/5786541 ◽

2017 ◽

Vol 2017 ◽

pp. 1-6 ◽

Cited By ~ 10

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.

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On the Chemistry of Tetrabenzyl Thiuram Disulfide and Tetramethyl Thiuram Disulfide with Bis (Triethoxysilylpropyl) Tetrasulfide in Silica Compounds

Rubber Chemistry and Technology ◽

10.5254/1.3547778 ◽

2003 ◽

Vol 76 (4) ◽

pp. 876-891 ◽

Cited By ~ 1

Author(s):

R. N. Datta ◽

A. G. Talma ◽

S. Datta ◽

P. G. J. Nieuwenhuis ◽

W. J. Nijenhuis ◽

...

Keyword(s):

High Performance ◽

Room Temperature ◽

Succinic Anhydride ◽

Dynamic Properties ◽

The Other ◽

Resonance Spectroscopy ◽

Reaction Products ◽

Negative Effect ◽

Higher Temperature ◽

Analytical Tools

Abstract The use of thiurams such as Tetramethyl thiuram disulfide (TMTD) or Tetrabenzyl thiuram disulfide (TBzTD) has been explored to achieve higher cure efficiency. The studies suggest that a clear difference exists between the effect of TMTD versus TBzTD. TMTD reacts with Bis (triethoxysilylpropyl) tetrasulfide (TESPT) and this reaction can take place even at room temperature. On the other hand, the reaction of TBzTD with TESPT is slow and takes place only at higher temperature. High Performance Liquid Chromatography (HPLC) with mass (MS) detection, Nuclear Magnetic Resonance Spectroscopy (NMR) and other analytical tools have been used to understand the differences between the reaction of TMTD and TESPT versus TBzTD and TESPT. The reaction products originating from these reactions are also identified. These studies indicate that unlike TMTD, TBzTD improves the cure efficiency allowing faster cure without significant effect on processing characteristics as well as dynamic properties. The loading of TESPT is reduced in a typical Green tire compound and the negative effect on viscosity is repaired by addition of anhydrides, such as succinic anhydride, maleic anhydride, etc.

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An SEM Investigation of the Pozzolanic Activity of a Waste Catalyst from Oil Refinery

Microscopy and Microanalysis ◽

10.1017/s1431927612013037 ◽

2012 ◽

Vol 18 (S5) ◽

pp. 75-76

Author(s):

C. Costa ◽

P. Marques ◽

P. A. Carvalho

Keyword(s):

Zeolite Y ◽

Active Phase ◽

Pozzolanic Reaction ◽

High Reactivity ◽

Oil Refinery ◽

Engineering Properties ◽

Partial Replacement ◽

Reaction Products ◽

Fcc Catalyst ◽

Cement Based Materials

The most active phase of the fluid catalytic cracking (FCC) catalyst, used in oil refinery, is zeolite-Y which is an aluminosilicate with a high internal and external surface area responsible for its high reactivity. Waste FCC catalyst is potentially able to be reused in cement-based materials - as an additive - undergoing a pozzolanic reaction with calcium hydroxide (Ca(OH)2) formed during cement hydration. This reaction produces additional strength-providing reaction products i.e., calcium silicate hydrate (C-S-H) and hydrous calcium aluminates (C-A-H) which exact chemical formula and structure are still unknown. Partial replacement of cement by waste FCC catalyst has two key advantages: (1) lowering of cement production with the associated pollution reduction as this industry represents one of the largest sources of man-made CO2 emissions, and (2) improving the mechanical properties and durability of cement-based materials. Despite these advantages, there is a lack of fundamental knowledge on pozzolanic reaction mechanisms as well as spatial distribution of porosity and solid phases interactions at the microstructural level and consequently their relationship with macroscopical engineering properties of catalyst/cement blends.

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RELATIONSHIPS BETWEEN SOME PROPERTIES OF ORGANIC SOILS FROM THE SOUTHERN CANADIAN SHIELD

Canadian Journal of Soil Science ◽

10.4141/cjss90-037 ◽

1990 ◽

Vol 70 (3) ◽

pp. 363-377 ◽

Cited By ~ 5

Author(s):

D. ANN BROWN ◽

S. P. MATHUR ◽

ANTON BROWN ◽

D. J. KUSHNER

Keyword(s):

Principal Component Analysis ◽

Acid Leaching ◽

Principal Component ◽

Organic Soil ◽

Component Analysis ◽

Soil Types ◽

Organic Soils ◽

Mining Districts ◽

Two Populations ◽

Inorganic Components

Different numerical methods used to distinguish between organic soil types are evaluated. The research was initiated by the suggestion that acid leaching from mining wastes could be prevented by capping the tailings with a self-renewing methane-producing muskeg bog, in order to prevent the penetration of oxygen to the wastes. Thirty organic soils from bogs in the mining districts of Elliot Lake, Sudbury, and Timmins, Ontario, and Noranda, Quebec, were sampled and 28 soil characteristics were measured. These characteristics, whose values are normally or lognormally distributed, were analyzed by several different statistical methods. Some characteristics indicate the existence of two populations, and others are bivariantly correlated. Canonical discriminant analysis was more successful than cluster analysis in separating the bogs into well-defined geographical groups. However, principal component analysis proved best at grouping the organic soils according to their organic and inorganic components, and we suggest that this is a suitable method for the general discrimination of organic soil types. Methane was present in all the 17 bogs tested for it, and in two very wet bogs more than 2 mmol of methane per liter were extracted. Key words: Muskeg bog, organic soils, soil characterization, principal component analysis

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A Novel Approach to the Analysis of the Soil Consolidation Problem by Using Non-Classical Rheological Schemes

Applied Sciences ◽

10.3390/app11051980 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1980

Author(s):

Kazimierz Józefiak ◽

Artur Zbiciak ◽

Karol Brzeziński ◽

Maciej Maślakowski

Keyword(s):

Constitutive Models ◽

Organic Soil ◽

Organic Soils ◽

Soil Consolidation ◽

Flexible Tool ◽

One Dimensional ◽

Novel Approach ◽

Soil Skeleton ◽

The One ◽

The Relationship

The paper presents classical and non-classical rheological schemes used to formulate constitutive models of the one-dimensional consolidation problem. The authors paid special attention to the secondary consolidation effects in organic soils as well as the soil over-consolidation phenomenon. The systems of partial differential equations were formulated for every model and solved numerically to obtain settlement curves. Selected numerical results were compared with standard oedometer laboratory test data carried out by the authors on organic soil samples. Additionally, plasticity phenomenon and non-classical rheological elements were included in order to take into account soil over-consolidation behaviour in the one-dimensional settlement model. A new way of formulating constitutive equations for the soil skeleton and predicting the relationship between the effective stress and strain or void ratio was presented. Rheological structures provide a flexible tool for creating complex constitutive relationships of soil.

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A fertile peatland forest does not constitute a major greenhouse gas sink

Biogeosciences ◽

10.5194/bg-10-7739-2013 ◽

2013 ◽

Vol 10 (11) ◽

pp. 7739-7758 ◽

Cited By ~ 33

Author(s):

A. Meyer ◽

L. Tarvainen ◽

A. Nousratpour ◽

R. G. Björk ◽

M. Ernfors ◽

...

Keyword(s):

Greenhouse Gas ◽

Eddy Covariance ◽

Organic Matter Content ◽

C Sequestration ◽

Organic Soil ◽

Organic Soils ◽

Indirect Approach ◽

Short Period ◽

N2o Fluxes ◽

C Assimilation

Abstract. Afforestation has been proposed as a strategy to mitigate the often high greenhouse gas (GHG) emissions from agricultural soils with high organic matter content. However, the carbon dioxide (CO2) and nitrous oxide (N2O) fluxes after afforestation can be considerable, depending predominantly on site drainage and nutrient availability. Studies on the full GHG budget of afforested organic soils are scarce and hampered by the uncertainties associated with methodology. In this study we determined the GHG budget of a spruce-dominated forest on a drained organic soil with an agricultural history. Two different approaches for determining the net ecosystem CO2 exchange (NEE) were applied, for the year 2008, one direct (eddy covariance) and the other indirect (analyzing the different components of the GHG budget), so that uncertainties in each method could be evaluated. The annual tree production in 2008 was 8.3 ± 3.9 t C ha−1 yr−1 due to the high levels of soil nutrients, the favorable climatic conditions and the fact that the forest was probably in its phase of maximum C assimilation or shortly past it. The N2O fluxes were determined by the closed-chamber technique and amounted to 0.9 ± 0.8 t Ceq ha−1 yr−1. According to the direct measurements from the eddy covariance technique, the site acts as a minor GHG sink of −1.2 ± 0.8 t Ceq ha−1 yr−1. This contrasts with the NEE estimate derived from the indirect approach which suggests that the site is a net GHG emitter of 0.6 ± 4.5 t Ceq ha−1 yr−1. Irrespective of the approach applied, the soil CO2 effluxes counter large amounts of the C sequestration by trees. Due to accumulated uncertainties involved in the indirect approach, the direct approach is considered the more reliable tool. As the rate of C sequestration will likely decrease with forest age, the site will probably become a GHG source once again as the trees do not compensate for the soil C and N losses. Also forests in younger age stages have been shown to have lower C assimilation rates; thus, the overall GHG sink potential of this afforested nutrient-rich organic soil is probably limited to the short period of maximum C assimilation.

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