1,720,978 research outputs found
Effect of Amino-2-Pyridine Inhibitor on the Rehabilitation of Chloride Contaminated Reinforced Concrete with Bidirectional Electro-migration Method
No full textThe corrosion of reinforcement presents a significant durability challenge, leading to a
reduced design life of reinforced concrete structures. With the growing demand for longer
service lives of infrastructure (typically 100–120 years) and the high costs involved in
construction and maintenance, the repair and rehabilitation of concrete structures have
become of utmost importance. To address this issue, a novel method known as
Bidirectional Electro-Migration Rehabilitation (BIEM) technology has been developed
to enhance the durability of existing reinforced concrete structures. The BIEM process
involves applying an electric field between embedded steel cathodes and external anodes
to inject a corrosion inhibitor from external electrolytes into the concrete while
simultaneously extracting chloride ions from the concrete cover zone. As observed from
the literature review in most of the research studies TETA was used as inhibitor so in this
thesis the effectiveness of 2AP was studied, effect of Amino-2-Pyridine Inhibitor on the
Rehabilitation of Chloride Contaminated Reinforced Concrete with Bidirectional Electromigration method. The effectiveness of the BIEM repair technique was investigated on
different aspects as current density, duration of treatment, initial chloride content and
variation of inhibitor in the electrolyte.
In experimental studies, specimens were treated using the BIEM method, and then drilled
to analyse the concentration profiles of corrosion inhibitor and chloride within the
concrete. Along with it Icorr, Ecorr, HCP and LPR of the specimens was also monitored
and investigated along with chloride and inhibitor profiles. The optimum results was
found in the case of 15 of test duration, 1 A current density at 0.3 M inhibitor
concentration. The maximum migration of inhibitor was observed 9.16 mM and
maximum extraction of chloride ions was 47%. Overall, the BIEM technology shows
promise in improving the durability and extending the service life of existing reinforced
concrete structures, making it a potential solution for addressing the challenges of
concrete corrosion and enhancing the sustainability of infrastructur
A Comparative Study of Wind Effect on High Rise Building Using American and Indian Wind Standards
No full textThis M.Tech thesis presents a comprehensive comparison of wind loading codes for highrise buildings, focusing on the American Society of Civil Engineers (ASCE) 7- 22 and the
Indian Standard (IS) 875 (2015) - Part 3. The study evaluates the response of buildings to
wind loads through dynamic analysis, considering various dynamic wind characteristics. A
set of 151.2m high-rise buildings of different shapes were subjected to analysis, alongside an
80m height building for further examination of different building geometries.
The comparative analysis primarily focuses on terrain category 3 for both codes, with a
meticulous examination of parameters such as design wind pressure at different heights,
base shear, storey drift and storey displacement. The aim of this research is to provide
insights into the variations between international wind loading standards, particularly in
comparison with the Indian wind loading standard.
Through rigorous analysis and comparison, this study sheds light on the disparities in wind
load assessments and their implications on structural design and safety. The findings
presented in this thesis contribute to enhancing understanding and improving the application
of wind loading codes in the design and construction of tall buildings, facilitating better
structural performance and resilience in diverse geographical contexts
Effect of LD Slag and Copper Slag as Sand Replacement on Self-Sensing Properties of Cementitious Composites
No full textThe abstract of the thesis "Effect of LD Slag and Copper Slag as Sand Replacement on Self-Sensing Properties of Cementitious Composites” investigates the possibility of using copper slag and LD slag as conductive fillers in cement mortar. The study aims to improve the electrical and mechanical properties of cementitious composites by adding these industrial by- products. Copper slag, a by-product of the copper smelting process, is known for its excellent mechanical and conductivity qualities, making it an ideal filler. LD slag, a by-product of the steel making process, has significant concentrations of calcium oxide and other inorganic components, which contribute to its cementitious qualities. The study investigates the effects of various materials on workability, compressive strength, and flexural strength, electrical and piezoelectric properties of cement mortar. Furthermore, the research involves microstructural characterization using SEM to better understand the interaction between the fillers and the cement matrix. The findings indicate that the addition of copper slag and LD slag may significantly improve the electrical and mechanical performance of cement mortar, giving a sustainable and cost-effective choice for the construction sector. The study highlights the potential of these by-products in substituting natural resources such as river sand, therefore resolving environmental concerns and improving the use of waste materials in construction. This concludes with recommendations for future research to improve the usage of these components in cementitious composites
Influence of Biochar Content and Curing Methods on the Physical And Mechanical Properties Of Non-Autoclaved Aerated Concrete
No full textThis study investigated the effects of biochar content and curing methods on the properties of non
autoclaved aerated concrete (NAAC). Cement was partially replaced with biochar at varying
percentages (0%, 2.5%, 3.5%, and 5%), and the resulting samples were subjected to steam curing,
moist curing, and carbonation curing. The primary objective was determining the optimal
conditions for enhancing NAAC's performance in bulk density, compressive strength, and drying
shrinkage. Results indicate that both biochar content and curing method significantly influence
NAAC properties. Bulk density increased with biochar content up to 3.5% for steam and moist
curing, subsequently decreasing slightly at 5%. Steam curing generally produced higher bulk
densities than moist curing, demonstrating its effectiveness in optimizing NAAC density.
Compressive strength followed a similar trend, with the highest strength achieved at 3.5% biochar
for both curing methods. Steam curing consistently yielded superior compressive strength values
compared to moist curing, suggesting its potential for enhancing NAAC's structural integrity and
suitability for load-bearing applications. Drying shrinkage increased with biochar content up to
3.5% for both curing methods but decreased at 5%. However, steam curing generally resulted in
higher shrinkage values than moist curing. Overall, this study underscores the importance of
carefully selecting biochar content and curing methods to optimize NAAC performance. Steam
curing is a promising approach for improving bulk density and compressive strength, although it
may lead to increased drying shrinkage
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Fifth International Conference on Sustainable Construction Materials and Technologies (SCMT5): Volume 3 (SCMT Conferences)
No full textThe performance testing of earthen materials:Challenges and future developments
Get PDFModern earth buildings are still a niche market despite their great potential to tackle some of the future challenges of the world housing shortage. The paper will discuss how to assess the engineering limitations of earthen architecture and the challenges faced by its development. As with any construction materials, it is crucial to know the limitations of the material to design and build safely. This is still an issue for earthen architecture, due to the variability of earths (local soils) and the lack of standard testing procedures. In this context, we will explain the work driven by the RILEM Technical committee 274-TCE.</p
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Effects of the nature of chemical activator on the compressive strength of calcined clay geopolymer mortar
Get PDFLow purity kaolin clay is presently receiving attention as a promising aluminosilicate source that has the potential of extending the application of geopolymers because of its global abundance and low embodied energy, but its strength performance depends substantially on the calcination process, mineralogy of the clay, type and proportion of chemical activator etc. This work focuses on comparing the compressive strength of calcined clay geopolymer mortars activated by three forms of chemical activators. Three groups of geopolymer mortar mixes were prepared and tested, group one utilizessodium hydroxide solution (NaOH) prepared by adding 68% water to the pellets 24 hrs prior to mixing, group two based on sodium silicate solution derived by adding 55.9% water to sodium metasilicate pentahydrate (Na2SiO3.5H2O) 24 hrs prior to mixing, while the group three mixes were activated with industry produced Na2SiO3 solution that has 54.5% solid component. The results show that high compressive strength is achieved by developing calcined clay geopolymer mortar using high viscosity industry produced sodium silicate solution, while very low strength is achieved by utilizing sodium silicate containing chemically bounded water. The result further shows that thecompressive strength of the geopolymer mortars are enhanced by sealed curing of the samples.<br/
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