scholarly journals Influence of Lime and Volcanic Ash on the Properties of Dune Sand as Sustainable Construction Materials

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 645
Author(s):  
Faisal I. Shalabi ◽  
Javed Mazher ◽  
Kaffayatullah Khan ◽  
Muhammad Nasir Amin ◽  
Alaa Albaqshi ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Volcanic Ash ◽  
Construction Materials ◽  
Chemical Characteristic ◽  
Laser Scanning Microscopy ◽  
Engineering Properties ◽  
Sustainable Construction ◽  
Dune Sand ◽  
Engineering Construction ◽  
Base Course

This study focused on evaluating dune sand stabilized with lime and volcanic ash as base course materials in engineering construction. Dune sands are found in Saudi Arabia in huge quantities. Due to the high demand for construction materials, this makes them highly suitable for construction. A testing program was designed to investigate the effect of adding different percentages by weight of lime (L: 0, 2, 4, and 6%) and volcanic ash (VA: 0, 1, 3, and 5%) on the engineering properties of the stabilized mixture. Unconfined compressive strength (UCS) and California bearing ratio (CBR) tests were conducted. In addition, Raman spectroscopy and laser-scanning microscopy (LSM) tests were performed to explore the chemical characteristic, packing, and structure of the mixture. The results showed that the UCS, CBR, and the Young’s modulus (Es) of the treated dune sand increased with the increase in percentage of both stabilizers. Furthermore, LSM images of mortar blended with intermediate L-to-VA blend ratio ≈0.55 (L: 6% and VA: 5%) exhibit compact packing of sand grains, indicating strong adhesion and higher cementing value. The results of the study are promising and encourage using the treated dune sand in engineering construction even with a low percentage use of lime (2%) and volcanic ash (1–3%) as stabilizers.

scholarly journals Cement-Stabilized Waste Sand as Sustainable Construction Materials for Foundations and Highway Roads

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 600 ◽  
Author(s):  
Faisal Shalabi ◽  
Javed Mazher ◽  
Kaffayatullah Khan ◽  
Mohammed Alsuliman ◽  
Ibrahim Almustafa ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Laser Scanning ◽  
Cement Content ◽  
Construction Material ◽  
Laser Scanning Microscopy ◽  
Tangent Modulus ◽  
Sustainable Construction ◽  
Dry Density ◽  
X Ray ◽  
Initial Tangent Modulus

In this study, cement-treated waste sand as a by-product material produced from Al-Ahsa quarries (Saudi Arabia) was experimentally tested and investigated as a base course material for the foundation of structures and roads. The study aimed to use the waste sand as a construction material by improving its strength, bearing capacity, and stiffness. The waste sand was mixed with different percentages of Portland cement content (0, 2, 4, 6, and 8%) at the maximum dry density and optimum water content of the standard Proctor compaction conditions of a non-treated sample. Unconfined compressive strength and California Bearing Ratio (CBR) tests for different curing times were conducted. X-ray diffraction (XRD), laser-scanning microscopy (LSM), and X-ray spectroscopy (XPS) were used to explore the microstructure and composition of the treated sand. The results showed that the compressive strength, initial tangent modulus, and CBR of the treated sand increase with the increase in cement content and curing time. Furthermore, good correlations were established among the strength, initial tangent modulus, and CBR. Based on the obtained results, cement-stabilized waste sand is a potential material for use in construction. This is expected to save the environment and reduce the cost of road construction.

Enhancing the Engineering Properties of Indian Black Cotton Soil with Municipal Solid Waste Incineration Ash – A Review

2021 ◽  
Vol 23 (3) ◽  
Author(s):  
Karanbir Singh Randhawa ◽  
◽  
Rajiv Chauhan ◽  
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Expansive Soils ◽  
Construction Materials ◽  
Waste Incineration ◽  
Green Technology ◽  
Engineering Properties ◽  
Sustainable Construction ◽  
Black Cotton Soil ◽  
Greenhouse Emissions

The present study is the review of work carried out by various researchers on the improvement of engineering properties of expansive soils namely Indian Black Cotton Soil (BCS), after the addition of MSWI ash to the soil in varying proportions. The findings of study indicate that the optimum content of MSWI ash to be added to expansive soils for improvement in strength characteristics varies between 10% and 30% with best results at 25% of MSWI ash proportion. This content of MSWI ash increases the UCS of expansive black cotton soil from 28.8 kPa to 53.4 kPa and an increase in CBR value from 3.38% to 9.38%. The review suggests the use of MSWI ash in India keeping in view the enormous increase in volumes of municipal solid waste (MSW) due to fast urbanization in the country. The extensive use of such green technology will go a long way in reducing requirement of civil construction materials thereby lowering greenhouse emissions. Simultaneously, cost effectiveness in improvement of weak soils to be used in Highway subgrade civil engineering applications using MSWI ash will result is sustainable construction practices.

scholarly journals Physical and Mechanical Properties of Granulated Rubber Mixed with Granular Soils—A Literature Review

2021 ◽  
Vol 13 (8) ◽  
pp. 4309
Author(s):  
Ali Tasalloti ◽  
Gabriele Chiaro ◽  
Arjun Murali ◽  
Laura Banasiak
Keyword(s):  
Review Paper ◽  
Low Cost ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Engineering Properties ◽  
Sustainable Construction ◽  
Granular Soils ◽  
Compression Properties ◽  
Potential Applicability ◽  
Recycled Rubber

End-of-life tires (ELTs) represent a great source of readily available, low-cost and sustainable construction materials having excellent engineering properties. Their reuse (in the form of granulated rubber mixed with soils) in large-volume recycling civil (geotechnical) engineering applications would be beneficial and should be encouraged. It is estimated that at present worldwide only less than 10% of ELTs are reused in geotechnical applications, while nearly 40% are recycled as tire-derived fuel. Although many studies have focused on the material characterization of soil-rubber mixtures (SRMs), it appears that the results of such investigations have not been properly compiled and compared, making it difficult to fully understand the potential applicability of SRMs. In an attempt to provide useful insights facilitating the use of SRMs as geotechnical construction materials, this review paper presents a comprehensive review of published research on the engineering properties of granular soils (i.e., mainly sand and gravel) blended with various recycled rubber inclusions. Available experimental data are scrutinized, and the results of the analyses are presented and discussed primarily in terms of effects of rubber content and aspect ratio (ratio of rubber to gravel median particle sizes) on compaction, permeability, strength and compression properties along with dynamic and cyclic deformation characteristics of SRMs. This review paper may help to alleviate the concerns of designers and consumers and encourage and further promote the use of recycled rubber tires on a larger scale in civil engineering projects.

scholarly journals Engineering Properties of Concrete Made with Coal Bottom Ash as Sustainable Construction Materials

2022 ◽  
Vol 8 (1) ◽  
pp. 181-194
Author(s):  
Fanny Monika ◽  
Hakas Prayuda ◽  
Martyana Dwi Cahyati ◽  
Erwiena Nurmala Augustin ◽  
Hilal Aulia Rahman ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Bottom Ash ◽  
Construction Materials ◽  
Engineering Properties ◽  
Sustainable Construction ◽  
Full Potential ◽  
Fine Aggregate ◽  
Concrete Production ◽  
Hardened Properties

Concrete is considered one of the construction materials that contribute the most significant carbon dioxide in the world. Meanwhile, according to various studies, concrete production will continue to rise through 2050, especially in developing countries. According to several reports, cement manufacture is one of the largest sources of carbon dioxide in the concrete sector. In addition, overexploitation of aggregates due to concrete production also causes unavoidable natural damage. Bottom ash waste was used as a replacement for cement and fine aggregate as sustainable construction materials. It is envisaged that this research would allow industrial waste to be utilized to its full potential, resulting in a concrete that is more environmentally friendly and minimizes carbon dioxide emissions during the manufacturing process. This study is divided into bottom ash as a cement substitute and bottom ash as a fine aggregate substitute. The engineering properties of the concrete were checked during the experiments in this study when it was fresh and hardened states. The slump test is used to determine the workability of fresh concrete. While for the hardened properties tests consist of compressive strength, splitting tensile strength, flexural strength, and mass density. The usage of bottom ash as a cement replacement demonstrates that as the composition of bottom ash increases, the performance of the hardened properties of concrete decreases. While using bottom ash as a fine aggregate replacement reveals that the performance of hardened properties has improved as the proportion of bottom ash utilized has increased. Doi: 10.28991/CEJ-2022-08-01-014 Full Text: PDF

scholarly journals Binders alternative to Portland cement and waste management for sustainable construction – Part 2

2018 ◽  
Vol 16 (4) ◽  
pp. 207-221 ◽  
Author(s):  
Luigi Coppola ◽  
Tiziano Bellezze ◽  
Alberto Belli ◽  
Maria C Bignozzi ◽  
Fabio Bolzoni ◽  
...  
Keyword(s):  
Waste Management ◽  
Portland Cement ◽  
Cultural Heritage ◽  
Natural Resources ◽  
Chemical Nature ◽  
State Of The Art ◽  
Construction Materials ◽  
Engineering Properties ◽  
Sustainable Construction ◽  
Free Lime

The paper represents the “state of the art” on sustainability in construction materials. In Part 1 of the paper, issues related to production, microstructures, chemical nature, engineering properties, and durability of mixtures based on binders alternative to Portland cement were presented. This second part of the paper concerns the use of traditional and innovative Portland-free lime-based mortars in the conservation of cultural heritage, and the recycling and management of wastes to reduce consumption of natural resources in the production of construction materials. The latter is one of the main concerns in terms of sustainability since nowadays more than 75% of wastes are disposed of in landfills.

3-D imaging of cells using a confocal laser scanning microscope and digital image processing

1988 ◽  
Vol 46 ◽  
pp. 96-97
Author(s):  
Thomas M. Jovin ◽  
Michel Robert-Nicoud ◽  
Donna J. Arndt-Jovin ◽  
Thorsten Schormann
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning Microscope ◽  
Laser Scanning Microscopy ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Scanning Microscope ◽  
Laser Scanning Microscope ◽  
Biochemical Processes ◽  
Adjacent Structures

Light microscopic techniques for visualizing biomolecules and biochemical processes in situ have become indispensable in studies concerning the structural organization of supramolecular assemblies in cells and of processes during the cell cycle, transformation, differentiation, and development. Confocal laser scanning microscopy offers a number of advantages for the in situ localization and quantitation of fluorescence labeled targets and probes: (i) rejection of interfering signals emanating from out-of-focus and adjacent structures, allowing the “optical sectioning” of the specimen and 3-D reconstruction without time consuming deconvolution; (ii) increased spatial resolution; (iii) electronic control of contrast and magnification; (iv) simultanous imaging of the specimen by optical phenomena based on incident, scattered, emitted, and transmitted light; and (v) simultanous use of different fluorescent probes and types of detectors.We currently use a confocal laser scanning microscope CLSM (Zeiss, Oberkochen) equipped with 3-laser excitation (u.v - visible) and confocal optics in the fluorescence mode, as well as a computer-controlled X-Y-Z scanning stage with 0.1 μ resolution.

Vacuoles Induced in Mammalian Cells by Helicobacter Cytotoxin are Acidic Organelles

1990 ◽  
Vol 48 (3) ◽  
pp. 168-169
Author(s):  
M. H. Chestnut ◽  
C. E. Catrenich
Keyword(s):  
Acridine Orange ◽  
Mammalian Cells ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Ulcer Disease ◽  
Gastroduodenal Disease ◽  
H Pylori

Helicobacter pylori is a non-invasive, Gram-negative spiral bacterium first identified in 1983, and subsequently implicated in the pathogenesis of gastroduodenal disease including gastritis and peptic ulcer disease. Cytotoxic activity, manifested by intracytoplasmic vacuolation of mammalian cells in vitro, was identified in 55% of H. pylori strains examined. The vacuoles increase in number and size during extended incubation, resulting in vacuolar and cellular degeneration after 24 h to 48 h. Vacuolation of gastric epithelial cells is also observed in vivo during infection by H. pylori. A high molecular weight, heat labile protein is believed to be responsible for vacuolation and to significantly contribute to the development of gastroduodenal disease in humans. The mechanism by which the cytotoxin exerts its effect is unknown, as is the intracellular origin of the vacuolar membrane and contents. Acridine orange is a membrane-permeant weak base that initially accumulates in low-pH compartments. We have used acridine orange accumulation in conjunction with confocal laser scanning microscopy of toxin-treated cells to begin probing the nature and origin of these vacuoles.

Sign in / Sign up

Export Citation Format

Share Document