Influence of Bagasse Ash as Partial Replacement of Cement on Soft Soil Improvement

Compressive strength of soft soil improvement using cement only and cement partial replacement with bagasse ash were studied. The strength characteristic of stabilized soil was investigated with various curing times of 7, 14 and 28 days. Tested result reveal the stabilized soil strength have trend to increase with time. Using 20% of bagasse ash by dry weight was suggested as optimum content for cement replacement to obtain highest strength. Comparing with cement improved soil, the stabilized soil strength of 20% BA replacement had higher over 25% and modulus of elasticity (E50) was increased up to 37% at 28 days of curing. Change on stabilized soil structure was observed by scanning electron microscopy (SEM) reveal that the formation of hydration reaction product, CSH fabric and rod-like ettringite, have transformed stabilized soil structure denser and harder consequence increase in soil strength with time.

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Strength Characteristics and Microstructure of Cement Stabilized Soft Soil Admixed with Silica Fume

Materials ◽

10.3390/ma14081929 ◽

2021 ◽

Vol 14 (8) ◽

pp. 1929

Author(s):

Nan Jiang ◽

Changming Wang ◽

Zeping Wang ◽

Bailong Li ◽

Yi-ao Liu

Keyword(s):

Silica Fume ◽

Soft Soil ◽

Hydration Product ◽

Soil Improvement ◽

Hydration Reaction ◽

Pozzolanic Material ◽

Stabilized Soil ◽

Construction Efficiency ◽

Cement Hydration Reaction ◽

Recycled Material

Soft soil improvement is an important subject in civil engineering, and searching for an effective admixture is an important research. Silica fume (SF) is a kind of recycled material, it can be used in engineering as a pozzolanic material. The main objective of this study is to assess the effectiveness of industrial waste silica fume (SF) as an admixture to improve the cement stabilized soft soil. The unconfined compressive test (UCT) and scanning electron microscopy (SEM) test of cement stabilized soil with different SF contents and different curing times have been carried out. UCT after 28 days revealed that the addition of SF can effectively increase the strength of cement stabilized soil and reduce the amount of cement, and 1.5% SF content is considered optimum, excessive SF will not further increase the strength. SF helped to accelerate the cement hydration reaction and significantly improve the early-age strength of stabilized soil even at 3 days, which can improve construction efficiency in actual projects. SEM analyses shows that the proper SF content could make the hydration product calcium silicate hydrate gel (CSH) fill the pores and increase the strength of the material, but excessive SF will increase the large pores content of the material and reduce the strength. This provided a basis for application of SF in improving soft soil.

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EFFECT OF DIFFERENT TYPES OF RICE HUSK ASH ON SOME GEOTECHNICAL PROPERTIES OF CEMENT-ADMIXED SOIL

Iraqi Geological Journal ◽

10.46717/igj.53.2c.1rs-2020-09-01 ◽

2020 ◽

Vol 53 (2C) ◽

pp. 1-12

Author(s):

Duong Nguyen

Keyword(s):

Rice Husk ◽

Soil Stabilization ◽

Rice Husk Ash ◽

Soft Soil ◽

Dry Weight ◽

Soil Improvement ◽

Soil Strength ◽

Atterberg Limits ◽

Treated Soil ◽

Soil Cement

Rice husk ash (RHA) is an agricultural residue and has shown great potential for soil stabilization. However, the research on the utilization of RHA for soft soil improvement using cement deep mixing method is still limited and the efficiency of using different RHA types for soil improvement needs to be clarified. In this study, the effect of different RHA types on Atterberg limits, unconfined compressive strength (UCS), and elastic modulus (E50) of soil-cement mixtures will be investigated. Two types of RHA which obtained from open fire burning (RHA1) and burning in a furnace under controlled conditions of temperature and duration of burning (RHA2), were used for this study. The RHA contents from 0 to 15% and 10% cement of the dry weight of the soil were used to treat the soft soil. The research results show that the types of RHA insignificantly affect the change in Atterberg limits of cement-admixed soil. Regarding the soil strength, the RHA2 shows a higher efficiency in the enhancement of treated soil strength at 28 days of curing than the RHA1. The addition of 12% RHA2 to the cement-admixed soil can increase the UCS and E50 values of treated soil by more than 50%.

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PLANNING OF SOFT SOIL IMPROVEMENT WITH PRELOADING AND PREFABRICATED VERTICAL DRAIN METHOD

Jurnal Rekayasa Sipil dan Lingkungan ◽

10.19184/jrsl.v2i01.7543 ◽

2018 ◽

Vol 2 (01) ◽

pp. 19

Author(s):

Ana Crosita Ningsih ◽

Luthfi Amri Wicaksono ◽

Mokhamad Farid Ma'ruf

Keyword(s):

Urban Areas ◽

Soil Structure ◽

Soft Soil ◽

Soil Improvement ◽

Building Site ◽

Planning Time ◽

Coral Sand ◽

Rapid Construction ◽

Prefabricated Vertical Drain ◽

Surrounding Areas

The northern coastal areas of Java such as Gresik and surrounding areas have a soil structure of alluvium consisting of gravel / coral, sand, clay soil and shells. Soil basic conditions are soft enough to cause land subsidence (settlement). The need for rapid construction causes the urban areas to become less and more for development land. This requires the improvement of soft soil to be used as a building site. As for the method to be done in this planning using a combination of preloading and PVD methods to accelerate the process of land degradation. Based on the planning result, the total height of embankment (preloading) is 3.5 m and the planning time lasted 4 months. Soft soil improvement is done up to 25 m depth with PVD design using triangle pattern and space 1.3 m. The 95% consolidation decrease due to the load of embankment caused the soil to fall as deep as 1,928 m. In this planning use modeling Plaxis 8.6 2D and the resulting yield of soil is 1,990 m. Wilayah pesisir pantai utara Jawa seperti daerah Gresik dan sekitarnya mempunyai struktur tanah berupa alluvium yang terdiri dari batu kerikil/koral, pasir, tanah lempung dan pecahan kulit kerang. Kondisi tanah dasar yang cukup lunak menyebabkan terjadinya penurunan tanah (settlement). Adanya kebutuhan konstruksi yang semakin pesat menyebabkan wilayah perkotaan menjadi semakin sedikit untuk dijadikan lahan pembangunan. Hal ini mengharuskan dilakukannya upaya perbaikan tanah lunak agar bisa dijadikan lahan bangunan nantinya. Adapun pada metode yang akan dilakukan pada perencanaan ini menggunakan kombinasi metode preloading dan PVD untuk mempercepat proses penurunan tanah. Berdasarkan hasil perencanaan didapatkan total tinggi timbunan (preloading) adalah 3,5 m dan waktu perencanaan berlangsung 4 bulan. Perbaikan tanah lunak dilakukan sampai dengan kedalaman 25 m dengan desain PVD menggunakan pola segitiga dan spasi 1,3 m. Penurunan konsolidasi 95% akibat beban timbunan menyebabkan tanah turun sedalam 1,928 m. Pada perencanaan ini menggunakan pemodelan Plaxis 8.6 2D dan hasil penurunan tanah yang dihasilkan adalah sedalam 1,990 m.

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Model tests on biogrouted granular columns in soft soil

Canadian Geotechnical Journal ◽

10.1139/cgj-2020-0361 ◽

2021 ◽

Author(s):

Aamir Mahawish ◽

Abdelmalek Bouazza ◽

Will P. Gates

Keyword(s):

Electron Microscopy ◽

Soft Soil ◽

Kaolin Clay ◽

Treatment Technique ◽

Biochemical Treatment ◽

Replacement Ratio ◽

Soft Clays ◽

Surface Loads ◽

Granular Column ◽

Scanning Electron

This paper examines the possible use of a bio-cementation process to reduce excessive bulging that occurs during the loading of granular columns in soft clays. A 12-phase percolation biochemical treatment technique was used to bio-cement part of the columns targeting the columns upper section, where bulging usually occurs. Upon application of unit cell surface loads up to 350 kPa, placement of bio-cemented granular column substantially reduced the vertical strains by 43% to 48% compared with un-cemented granular column and 56% to 60% compared with unreinforced kaolin clay for just a low replacement ratio of 11%. Bulging was reduced by 62% to 75% following bio-cementation and mostly occurred where bio-cementation was less evident. Scanning electron microscopy and energy dispersive spectroscopy validated the existence of calcium carbonate. This study presents a relatively new alternative to reducing bulging in granular columns using a promising approach.

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Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

The Scientific World JOURNAL ◽

10.1155/2014/670710 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11

Author(s):

El-Sayed Negim ◽

Latipa Kozhamzharova ◽

Yeligbayeva Gulzhakhan ◽

Jamal Khatib ◽

Lyazzat Bekbayeva ◽

...

Keyword(s):

Electron Microscopy ◽

Compressive Strength ◽

Fly Ash ◽

Setting Time ◽

High Volume ◽

Physicomechanical Properties ◽

Partial Replacement ◽

Setting Times ◽

High Volume Fly Ash ◽

Scanning Electron

This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

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Fabrication of Advanced Cement Mortar for Building Anti-Bacterial Applications

Al-Khwarizmi Engineering Journal ◽

10.22153/kej.2019.07.004 ◽

2019 ◽

Vol 15 (1) ◽

pp. 89-96

Author(s):

Farhad M. Othman ◽

Alaa A. Abdul-hamead ◽

Noor A. Hmeed

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Cement Mortar ◽

Anatase Tio2 ◽

Partial Replacement ◽

Early Age ◽

Weight Percentage ◽

Atomic Force ◽

Nano Material ◽

Scanning Electron

In this research, we have added nano anatase TiO2 as a partial replacement of Portland cement by a weight percentage of (0.25 to 1%) for the development of properties for protection against bacteria. The control mix was made by using "the cement to sand" proportion about (1: 2.75) with the "water to cement" proportion of (0.5) to study the structure, porosity, water absorption, density, mechanical properties, as well as anti-bacterial behavior. Inspections have been done such as scanning electron microscopy (SEM), and atomic force microscope (AFM) for mortar. Experimental results showed that after the addition of Nano powders in cement mortar, the structural properties improved significantly with the development of hydration of cement mortar at early age, reduction of porosity and the increase of density as well as enhancement in compressive and anti-bacteria properties that make the preparation of nano material very suitable for protection against bacteria.

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629 Are Trichome Number Related to Parthenolide Content in Feverfew?

HortScience ◽

10.21273/hortsci.34.3.556a ◽

1999 ◽

Vol 34 (3) ◽

pp. 556A-556

Author(s):

Gretchen Hatch ◽

Albert H. Markhart

Keyword(s):

Electron Microscopy ◽

Active Ingredient ◽

Dry Weight ◽

Medicinal Herb ◽

Herbal Remedies ◽

Considerable Variability ◽

Rooted Cuttings ◽

The Relationship ◽

Plant Compounds ◽

Scanning Electron

The concentration of active ingredient in a given dry weight of a medicinal herb is important to the consumer and producer of herbal remedies. Feverfew is a commonly used medicinal herb where the active compound has been identified. There is considerable variability in the amount of the active ingredients in different genotypes of feverfew. Important secondary plant compounds are often produced in the trichomes of leaves. The objective of this investigation is to determine if there is a correlation between the number of leaf trichomes and the level of active ingredient in several feverfew genotypes. Rooted cuttings of feverfew (Chrysanthemum parthenium) genotypes previously characterized for parthenolide content were grown under identical conditions in an environmentally controlled greenhouse. Light and scanning electron microscopy were used to describe and quantify the number and type of trichomes on the youngest fully expanded leaf of each plant from each genotype. The relationship between trichome number and parthenolide content will be presented.

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Effects of cellulose nanocrystals as extender on physical and mechanical properties of wood cement composite panels

BioResources ◽

10.15376/biores.15.4.8291-8302 ◽

2020 ◽

Vol 15 (4) ◽

pp. 8291-8302

Author(s):

Mona Shayestehkia ◽

Habibollah Khademieslam ◽

Behzad Bazyar ◽

Hossein Rangavar ◽

Hamid Reza Taghiyari

Keyword(s):

Electron Microscopy ◽

Mechanical Properties ◽

Physical And Mechanical Properties ◽

Dry Weight ◽

Cement Composite ◽

Composite Panels ◽

Microstructural Properties ◽

Micro Structure ◽

Mechanical And Microstructural Properties ◽

Scanning Electron

The effects of cellulose nanocrystal (CNC) particles were investigated relative to the physical, mechanical, and microstructural properties of wood cement composite panels. Wood and cement were mixed at three ratios of 1:3, 1:3.5, and 1:4. Calcium chloride was added at 3 and 5%. CNC was added to the mixture at five levels (0, 0.1, 0.2, 0.5, and 1%, based on dry weight of cement). The results showed that CNC content of 0.5% had the best impact on the properties. The overall trend showed that with the addition of CNC, tensile, flexural, and physical properties of the composites were considerably enhanced. Scanning electron microscopy demonstrated that the addition of CNC was associated with an improved integrity in the micro-structure of panels.

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Effect of maltodextrin reduction and native agave fructans addition on the physicochemical properties of spray-dried mango and pineapple juices

Food Science and Technology International ◽

10.1177/1082013218769168 ◽

2018 ◽

Vol 24 (6) ◽

pp. 519-532 ◽

Cited By ~ 8

Author(s):

Darvin E Jimenez-Sánchez ◽

Montserrat Calderón-Santoyo ◽

Rosa I Ortiz-Basurto ◽

Pedro U Bautista-Rosales ◽

Juan A Ragazzo-Sánchez

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Storage Stability ◽

Partial Replacement ◽

Inlet Temperature ◽

Drying Process ◽

Spherical Powder ◽

Powder Particles ◽

Spray Dried ◽

Scanning Electron

The effects of the partial replacement of maltodextrin by native agave fructans on the characteristics of spray-dried pineapple and mango powder were evaluated in this study. An experimental 33 design, three concentrations of maltodextrin (5, 7, and 10%), three concentrations of native agave fructans (0, 2, and 4%), and three feed temperatures (110, 115, and 120 ℃) were used. The results using the treatment in which only maltodextrin was used as a reference indicated that an increment in the inlet temperature decreases the moisture content, aw, and solubility. Likewise, an increase (more than 2%) in fructans concentration generates products with increased aw, moisture, hygroscopicity, wettability, and greater solubility. Additionally, no modification of storage stability was observed. Mango and pineapple powder color were affected mainly by the inlet temperature, causing an increase in luminosity (L*) and a decrease in parameter ( a*). A scanning electron microscopy showed spherical powder particles with certain contractions; powder stability in treatments with native agave fructans was not modified in the treatment at 2%. Finally, the addition of 2% agave fructans as carrier material was able to reduce the maltodextrin concentration of the spray drying process.

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Effects of Nanoparticles on the Antipullout Strength between the Reinforcement and Cement Mortar

Advances in Civil Engineering ◽

10.1155/2020/8856647 ◽

2020 ◽

Vol 2020 ◽

pp. 1-8

Author(s):

Yupeng Shen ◽

Peng Jing ◽

Wensheng Yao ◽

Tianxiao Tang ◽

Dandan Cao ◽

...

Keyword(s):

Electron Microscopy ◽

Calcium Silicate Hydrate ◽

Cement Mortar ◽

Microscopic Analysis ◽

Specimen Size ◽

Reducing Agent ◽

Hydration Reaction ◽

Nano Silica ◽

Cement Based Materials ◽

Scanning Electron

Recently, the use of nanomaterials (i.e., Nano-Silica (NS) and Nano-SiC(NC)) to improve the mechanical properties and durability performances of cement-based materials has received considerable attention. This work presents the effects of nanoparticles (NS), the specimen size, and the water-reducing agent on the antipullout strength between the reinforcement and cement mortar on the basis of the laboratory antipullout tests. The mechanism is, then, validated by the microscopic analysis with Scanning Electron Microscopy (SEM). Results show that NS can accelerate the hydration reaction of cement, produce more Calcium Silicate Hydrate (CSH) gel, and increase the density of the cement mortar, thereby improving the microstructure and antipullout strength. The moderate NS (1.0%) is recommended to improve antipullout between the reinforcement and cement mortar. Besides, the specimen size and water-reducing agent have an obvious influence on the antipullout strength. These results would provide guidance on the design or construction of the cement mortar with reinforcement.

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