Casting Position Research Articles

Bond of FRP bars in fine‐grained alkali‐activated concrete

AbstractAlkali‐activated cement (AAC) is an alternative binder with a promising potential to replace ordinary Portland cement (OPC) and mitigate its environmental issues. The use of fiber‐reinforced polymer (FRP) reinforcements with AAC concrete enables the development of corrosion‐resistant, environmentally friendly reinforced concrete structures. Bond behavior is critical in reinforced concrete structures and must be thoroughly studied for such new alternative materials. This study employs pullout tests to investigate the bond behavior between FRP bars and fine‐grained AAC concrete. Three fine‐grained AAC concretes with low to high strength, glass and carbon FRP bars and wrapped, milled, and smooth surface treatments were examined. The effect of bar casting position was also investigated. The compressive strength showed a significant influence on the bond strength. An average bond strength of approximately 18 MPa was observed for both glass and carbon FRP bars when used with 65 MPa concrete. Both the glass and carbon FRP bars with wrapping showed a lower bond strength than their milled FRP bars counterparts. The carbon bars without surface preparation (smooth bars) resulted in a much lower bond strength, around 4 MPa. In terms of casting positions, the bars cast in the middle section of the concrete block showed a higher bond strength than those at the bottom and top.

Caste Transformation, Intracultural Communication, and Social Structure Dynamics in Kei Society, Southeast Maluku-Indonesia

This study investigates the system of social stratification and intracultural communication in the Kei people of Southeast Maluku, Indonesia, which is based on centuries-old caste traditions. Kei society is divided into three main classes: mel-mel (nobles), ren-ren (middle class), and iri-ri (lower class), each of which has roles and rights governed by local customary law, Larwul Ngabal. This caste system has created a recognized social balance despite certain dominance and hegemony. This research uses an ethnographic approach with a focus on direct observation, in-depth interviews, and document analysis to explore how stereotypes and social stratification are maintained through intracultural communication. The findings show that Kei people use language and cultural symbols to reinforce their caste position, while modernization and electoral politics open space for changes in social dynamics. The results of this study provide insights into how local communities adapt to modernization and democratization while maintaining traditional cultural structures. The implications of this study underscore the importance of understanding the dynamics of intracultural communication in the context of social stratification to maintain social order and promote inclusiveness in the social development of Kei society.

Caste and Gender: A Question on Women’s Sexuality in a Brahmanical Patriarchal System

In this paper the primary focus is given on the question of women’s sexuality. Women as a gendered category are never free; while the sexuality of the upper caste women is controlled by their male counterparts in the name of maintaining caste purity, the lower caste women are exploited sexually by the man of the upper caste. It has always been an existence of dominance on women’s sexuality whether she is in a position of upper strata in the caste system or in a lower position of the same. In a patriarchal society the domination on women’s sexuality is legitimized by the notion of ‘purity and pollution’ which is regarded as a central feature of the caste system. This paper is dealing with the primary concern on women’s sexuality; how being a woman (despite of their caste position) face subordination, discrimination throughout her life in a patriarchal society.

Intra- and inter-observer agreement in distal radius fracture dislocation measurement of casting position.

Most displaced distal radius fractures (DRF) are treated nonoperatively, with reduction and immobilization in a cast. Studies assessing intra- or inter-observer agreement on radiologic measurements of casting position have not been published, which was the aim of our study. Our study is based on the Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) study. All detected DRFs during the OSTPRE follow-up were retrieved and based on sample size calculations 50 fractures were randomly selected for the study. 5 independent reviewers measured dislocation parameters and wrist position in a cast from the radiographs. A linear mixed model was used to estimate the concordance correlation coefficient (CCC) and total deviance index (TDI) that were used to evaluate intra- and inter-observer agreement. We used Kappa values to determine intra- and inter-rater agreement on radiographically acceptable reduction of the DRF. Limits of acceptable position were those defined by Finnish Current Care Guidelines. For radial inclination, radial shortening, and dorsal/volar tilt, intra- and inter-observer correlations were high (CCC > 0.76). In addition, measurements of wrist angle in a splint had high correlations (CCC > 0.78), whereas measurement of intra-articular gap and step had poor correlations (CCC < 0.52). The Kappa value for overall agreement on the radiographically acceptable position of the DRF was modest (0.59). Intra- and inter-observer repeatability of casting position of radial inclination, radial shortening, and dorsal/volar tilt were high whereas intra-articular gap and step had poor correlations.

The Slipper Fracture: Revisited.

Objectives The term "slipper fracture" is usedto describe a fracture of the radius at the junction of the metaphysis and diaphysis. This fracture has an "evil" reputation because it often angulates in the cast.Historically, there have been differing opinions on the optimal way to cast slipper fractures either with a long arm cast in pronation or a long arm cast in supination to prevent angulation. The purpose of this study is to report the outcomes of "slipper fractures" treated with casting. Methods Sixteen slipper fractures were retrospectively reviewed. Electronic medical records (EMRs) and radiographs were analyzed to gather data on body weight, cast type, cast position, cast index, loss of reduction, cast wedging, repeat reduction, surgery, and amount of remodeling. Results The average age of the patients was eight years old. The average body weight was 30.4 kg.Initial casting included 14 long arm casts in neutral, one short arm cast, and one sugar tong splint. The average cast index was 0.87. Only one cast had a cast index of less than 0.8. This fracture was treated with a long arm cast and did not displace. Of the fractures,94% lost reduction in the cast and angulated an average of 26 degrees. Two cases were treated with a cast wedge; 13 were observed. Remodeling occurred at an average rate of 2.7 degrees/month. The average remodeling measured at the last follow-up was 15 degrees. Conclusion Slipper fractures are difficult to treat due to the angulation of the fracture in the cast. The current study indicates that a long arm cast,appropriate cast index, and cast position are key to preventing the loss of reduction or angulation of a slipper fracture.

A new fib Model Code proposal for a beam‐end type bond test

AbstractA beam‐end test is proposed in this paper and in the new fib Model Code 2020 to determine the effects of concrete type, confinement effects, and casting position on the anchorage strength of reinforcing bars. Two bars are cast in each specimen (in the two opposite corners), one in a “good” casting position and the other in “poor” casting position. The proposed test aims to be an economical bond test capable to represent actual conditions of anchored bars in real design practice. The test is also intended to verify whether existing provisions for bond and anchorage in the fib Model Code are suitable in nonconventional concrete. The validity of the proposed beam end type bond test is assessed by the results of more 60 tests on rebars having anchorage length of about 20 times the bar diameter in plain concrete, in fiber reinforced concrete, and in recycled aggregate concrete. Experimental results provide information both on the “top cast effect” in three types of concrete and on the effectiveness of fib Model Code provisions for anchorage when nonconventional concrete is used.

THE DISSOLUTION OF DESCENDED CASTE MARRIAGE AND ITS IMPLICATION ON BALINESE WOMEN: HUMAN RIGHT PERSPECTIVES

This paper analysis the dissolution of inter-caste marriages, nyerod ‘descended caste’ marriages, and their implications for Balinese women in the perspective of human rights. The focus of this research is the position of Balinese triwangsa caste women (those who are from Brahmana, Ksatriya, and Wesya) whose nyerod marriages are dissolved. The method used was the empirical legal research method using a statutory approach, a conceptual approach, an analytical approach, a sociological approach and a human rights approach. As an analytical tool for the legal issues studied, the theory of Human Rights (HAM) was applied because factually the Balinese customary law community is still attached to the recognition of caste even though there has been a Bali DPRD decision Number 11 of 1951 which negates the implementation Patiwangi ceremony, the ceremony of neutralizing one's caste position. The data used were obtained through direct observation and interviews with informants based on purposive sampling technique. The result of the analysis shows that the existence of caste in the Balinese customary law community is actually a burden for triwangsa women whose marriages are dissolved, because the Balinese triwangsa women who have chosen the nyerod marriages are considered out of their original caste, so they can no longer be recognized as part of the triwangsa clan, even though from a human rights perspective the Balinese customary law community highly respects human rights. However, in the event that the marriage was dissolved, socio-culturally it turned out that the elderly people from Puri or Griya, those who belong to triwangsa did not re-recognize the caste of Balinese women who were returning to their home family, even though they were their own biological children. The strong attitude of the elderly people of the Puri or Griya palaces in refusing nyerod marriages bring implication that the triwangsa women were afraid and ashamed to return to their original homes/family because they feel they are no longer part of the triwangsa clan.

Serviceability Limit States according to the new Eurocode 2 proposal: Description and justifications of the proposed changes

In this paper the main changes introduced into FprEN 1992-1-1:2022 with respect to the current version of EC2 (EN 1992-1-1:2004) with regard to cracking and deflection calculations areintroduced and justified. The changes introduced into the cracking formulation account for the variation of stresses in the tensioned zones for bending, the effect of the casting position and the influence of curvature on the increase of surface crack widths. The introduction of these effects, together with a reformulation of the effective area allow for a reduction of scatter in the model when compared to experimental data. For deflections, a simplified method is introduced which is fully consistent with the general method and allows practical application by providing correction factors to be applied to linear elastic calculations. From this method a formulation for the slenderness limits is deduced. This formulation is the basis for the table-based method to avoid deflection calculations. Finally coefficients are derived to translate the slenderness limits of beams to the slenderness limits of slabs supported on isolated columns and slabs supported on walls.

The effects of I-Beam thickness to microstructure and compression load of thin wall ductile iron connecting rod

Lighter automotive components are needed to reduce energy consumption. The manufacturing processes of the components should also consume less energy and be environmentally friendly. Aluminum is a lightweight material, but the manufacturing processes consume a lot of energy. Ductile iron has outstanding design flexibility and applying a thin wall casting technique to the ductile iron components will reduce the weight and make it possible for ductile iron to compete with lightweight materials. The achievement of making a 3 mm I-beam thickness connecting rod which fulfills the design requirement in previous research has encouraged a further reduction in the I-beam thickness. This action is taken to enhance the weight reduction gained from the connecting rod. The aims of this work are to ensure the repeatability resulting from the design of 3 mm I-beam thickness and the ability of the casting design to produce the 2 mm I-beam thickness. Solidification rates in thin wall casting are critical due to the differences in thicknesses in the product. It is also to analyze the effect of I-beam thickness on the compression load. Two types of I-beams, which differ in their thickness, 3 mm and 2 mm, were produced in the foundry scale. All the I-beams were characterized by their microstructure and compression load. The compression load was measured using the tensile method. The results of microstructure observations revealed that the microstructure in I-beam is different from the one in the end rod except for one casting position, while the result of compression load shows a similar value for average compression load between the 3 mm and 2 mm which fulfill the compression load requirement of connecting rod. The casting designs built in this research can produce thin wall ductile iron (TWDI) connecting rods that could stand similar load with the original one.

Effect of casting geometry on distributions of segmented steel fibers in ultra-high performance fiber-reinforced concrete

• 3D statistic of steel fiber dispersion of UHPFRC has been investigated. • Fibers tend to move along the major upward flow the composite. • Different flow patterns and orientations observed due to the wall effect. • Fiber content is the dominant factor affecting the 3D dispersion of fibers. In this study, influence of flow distance and casting direction to properties of steel fibers in ultra-high-performance fiber-reinforced concrete (UHPFRC) was investigated using 3D data on the fibers that accurately obtained through multiple microcomputed tomography (micro-CT) scans and image processing. 3D images of bundled fibers were separated to individual strands by means of a 3D watershed algorithm. The variation in fiber properties according to distance from the casting point and the casting direction was quantitatively analyzed. The results indicated that many fibers were distributed at the casting position for the horizontally casted specimen. The fibers tended to move along the major upward flow of the UHPFRC mixture, which in turn, gradually inclined upward and oriented horizontally in concentric circles. However, different major flow patterns and fiber orientations appeared depending on the casting direction due to the wall effects induced by formwork boundaries. It was also found that fiber content is the dominant factor affecting the 3D dispersion of fibers.

The surviving power of Brahmin privilege

The caste system in India traditionally confers immense prestige to upper caste Brahmins and severely curtails the backward castes. In spite of institutional efforts to diminish caste-based discrimination, several contemporary studies underscore the invisible ways in which caste operates. The central question that this article asks is, ‘How do Brahmins maintain and assert their privilege today?’. Focusing on the Brahmin residents of Deulpota (village in West Bengal) and rural Brahmin migrants in Kolkata (city), I trace their social networks to learn about how Brahmins subtly maintain their status and privilege in day-to-day life. I argue that Brahmins form and maintain social networks in ways which innocuously preserve their privileges through social capital accessed from diverse asymmetrical relations. These privileges and advantages are sustained through Brahmins’ networks of the instrumental kind. Wealthy Brahmins forge these relations to preserve their social position, their family lineage and to control the subordinates while the struggling resource-poor Brahmins use their caste position to cope with impediments of their class status. As such, this study shows how being Brahmin allows for easier access to important instrumental relations (which are not merely caste-based) and resources embedded in them.

Ethnicity/caste-based social differentiation and the consumption of clean cooking energy in Nepal: An exploration using panel data

Using a three-year panel data (2016–2018) of about 6000 households per year in Nepal, this study assesses the association between ethnicity and caste-based social differentiation and the consumption of clean cooking energy. This study applies a random effect logit model for analysing the factors explaining the choice of clean cooking energy and, in particular, the role of ethnicity/caste. To further examine the clean energy gap among different ethnicities and castes, this study applied exogenous switching treatment effect regression (ESTER). The results show that Dalits and Ethnic minorities are less likely to use clean cooking energy and the findings remain the same across all reasonable model specifications. More disaggregated analysis shows that Madheshi Dalit households are worse off, followed by Hill Dalit, Madheshi low-caste, Terai Adivasi, Other ethnic groups, and Hill Chhetri. The results of ESTER show that the difference observed in the use of clean cooking fuels between ethnic minorities and others is better explained by their base heterogeneity effects, while the clean cooking fuel differences between Dalits and non-Dalits are explained by both base heterogeneity and the treatment effects. It means that, unlike non-Dalit ethnic minorities, Dalits faced differential treatment due to their low caste position as well as their low-endowment ownership. Another major finding is that differences in endowment and education level largely explain differences in energy use. Hence, while assessing differences in energy use by caste/ethnic groups, one must control for the endowment and other human capital differences across the households that fall under different income or consumption quantiles. Clean energy policy should focus on improving access to clean energy, and it should pay particular attention to the Dalit communities and, to some extent, non-Dalit minorities by providing easy access and improving their purchasing power by increasing their asset endowment and income.

Bond degradation of rebar and concrete confined with corroded stirrups: effects of concrete grade and casting position

An experimental study was conducted to investigate the effects of stirrup corrosion, concrete strength and casting position on the behaviour of the bond between steel bars and concrete. Accelerated corrosion was applied to corrode the stirrups in concrete specimens under laboratory conditions. In total, 180 specimens were cast and tested in this experiment. The specimens had three nominal concrete strengths of C20, C40 and C50 with two deformed steel bars of 18 mm in diameter set in a 200 × 200 mm diagonal concrete prism with two stirrups of 8 mm in diameter to provide confinement. The steel bars were cast with different pouring positions, namely the upper and lower ends. Five corrosion levels were investigated, namely 0, 5, 10, 15 and 20%; 12 specimens were investigated for each corrosion level. A pull-out test was carried out to obtain the bond–slip curves. The test results indicate that the porosity of concrete has a great effect on bond degradation with the increase of the steel corrosion level.

Effect of Casting Position on Mechanical Performance of Ultra-High Performance Concrete.

The mechanical performance of ultra-high performance concrete (UHPC) is a function of fiber distribution and orientation, which are affected by the processing of the fresh material. In this study, the influences of two casting positions (mid-cast and end-cast) on strength and fracture properties of UHPCs with different fiber types and fiber contents were investigated. The results show that mid-cast specimens have higher flexural strength and fracture properties than end-cast specimens, while the compressive strength is almost unaffected by casting position. Compared to specimens with straight fibers, the flexural strength of specimens with hooked-end fibers is more likely to be affected by casting position. The residual load-to-peak load ratio is independent of casting position but affected by fiber type and fiber content.

Top cast effect: Influence of bond length on splitting mode failure

AbstractIt is widely considered that bond strength of bars cast near the top of a pour is weaker than that of bars cast near the bottom. The lesser strength of top cast bars is attributed to: (a)The increase in binder/cement ratio toward the top of a pour due to consolidation of fluid concrete prior to setting. (b)The formation of voids beneath bars as solids in fluid and setting concrete consolidate when the bar is restrained from vertical movement. The difference in bond strength bars cast near the top of a pour and those cast near the bottom varies widely between individual studies, with little difference reported in some studies and reductions in excess of 50% reported in others. A markedly greater top bar effect observed in pullout type specimens with short bond lengths compared to that in studies based on conditions more representative of practical construction. Through a simple analytical model of behavior of a lapped joint based on the local bond slip model in fib Model Code 2010, it is shown that the casting position effect diminishes as bond length increases. This influence is supported by analysis of trends in the top cast section of the ACI408 bond test database. Conclusions demonstrate the casting position factor in current design Codes significantly overestimates the top cast effect and justifies a casting position factor of 1.0 for laps designed to develop the full design strength of Grade 500 bars. Increased bond lengths would still be required for top cast laps designed for lower bar stresses.

Exploring Gender and Caste Intersectionality among Muslims: A Sociological Study

Aim Caste studies conducted among Muslims in India generally focus on establishing the existence of caste system among Muslims but they seldom talk about different types of oppression and inequalities faced byMuslim women.This empirical study exploreshow gender and caste identities and their mutual intersectionality impact education,occupation and income choices and actual attainments of Muslim women. Methods This study is part of a larger study conducted among Muslims of Kashmir in India.Primary datawas collected from 704 eligible respondents (Male=392, Female=312) using mixed methods. Three layers of ‘caste like’ and ‘caste’ groups existing in the research area are identified and gender situation within these groups are comparatively examined. Results Each of the ‘caste like’ and ‘caste’ groupshas patriarchal caste capital.Higher professions within the government and private services are largely acquired by upper caste male Muslims or other male and female Muslims having rich cultural and social capital. There is preponderance of lower caste male Muslims in low income self-employment but lower caste Muslim females seldom find say in family based business and compelled to join low paid private jobs. More than fifty percent educated Muslim females are unemployed. Conclusion Although patriarchy is the general rule here, not all women face discrimination and inequality in the same way. Upper caste Muslim women often witness so called benevolent restriction of choices whereas lower caste women are the most excluded and marginalised section of the society who face double discrimination due to patriarchy and interwoven caste positions which severely impacts their educational as well as employment choices and attainments.

Flow distance induced variation analysis of digitally segmented steel fibers in UHPFRC

Ultra-high performance fiber-reinforced concrete (UHPFRC) is a construction material with outstanding mechanical properties and durability. The degrees of dispersion and orientation of included steel fibers are known to have a decisive effect on UHPFRC’s material properties. In this study, UHPFRC specimens with different volumes of fibers were prepared to investigate the variation of spatial information of steel fibers in UHPFRC. Each sample was scanned individually through micro-computed tomography (micro-CT) to analyze the three-dimensional fiber statistics. To enhance the accuracy of the analysis, bundled fibers were digitally segmented through reliability-based maximum likelihood estimation (MLE) and a watershed algorithm. It was quantitatively found that the number of contact areas of bundled fibers decreased and fibers tended to be aligned more horizontally as flow distance increased. However, at the casting position and the opposite region, there was irregular distribution, which has the potential to affect the designed material properties of UHPFRC.

Casting Position for Distal Radius Fractures Changes Radiocarpal Joint Forces: A Cadaveric Study

Nonsurgical distal radius fracture treatment requires immobilization and classical teaching suggests varying cast positions. We investigated the effect of cast position on the force and pressure experienced by the articular cartilage in the scaphoid and lunate fossae. Ten fresh-frozen cadaveric specimens were used. A standardized extra-articular distal radius fracture was made. Force sensors were affixed to the articular cartilage of the scaphoid and lunate fossae. Baseline data were obtained. Specimens were then placed into a short arm cast with the wrist either neutrally aligned or flexed and ulnarly deviated (FUD). Specimens had a standard load applied, and a force profile was obtained. The cast was removed and the other cast type was placed and measurements were repeated. Overall force and pressure values were compared between baseline data and the 2 cast types. Additionally, differences in volar and dorsal scaphoid and lunate fossa forces and pressures were compared pairwise within the 2 cast types. The relative force and pressure values across cast types were also compared. Both cast types significantly reduced the median force and pressure experienced by the radiocarpal joint compared with no cast. In the FUD cast, the volar and dorsal lunate fossa experienced significantly greater force, and the dorsal lunate fossa experienced significantly greater pressure compared with the dorsal scaphoid fossa. There were no differences for any fossae in the neutral cast. When comparing between casts, the volar lunate fossa experienced a significantly greater relative force in the FUD cast compared with the neutral cast. Casting a distal radius fracture decreases the forces and pressures in the radiocarpal joint. Placing the wrist in a FUD position results in greater forces and pressures on the lunate fossa compared with the scaphoid fossa. When immobilization is needed, we advocate for the placement of patients in a relatively neutral short-arm cast with minimal FUD to avoid this increased pressure.

Spalling of concrete cover induced by reinforcement

This paper investigates the phenomenon of cover spalling in reinforced concrete induced by bond or by the action of an inner pressure. This research is based on an experimental programme comprising a series of bond tests and a series of tests with inner-pressure on cylindrical openings. The inner-pressure test series (aimed at representing the conditions occurring for instance due to corrosion of reinforcement) was performed with hydraulic inflator devices embedded within concrete openings near to the free concrete surface. By means of detailed surface measurements performed with Digital Image Correlation, the mechanisms triggering spalling failures and the associated resistance are discussed and analysed thoroughly. This series investigates in addition a number of phenomena relevant to spalling failures, such as the influence of the casting position, group and size effects. The observed response, analysed by means of a mechanical analogy, is later used to investigate a series of structural tests performed on pull-out specimens. This analysis highlights the analogies and differences between the two types of tests (subjected to an imposed pressure or to bond stresses). On that basis, a comprehensive approach for treatment of bond-related cases failing by cover spalling is proposed, showing consistent agreement to the experimental evidence.

In Search of Progress: Caste and the Modernity of the Left in Manik Bandyopadhay’s Short Stories of the Bengal Famine of 1943

This paper aims to explore the crucial import of caste in defining the modernity of the left. By examining Manik Bandyopadhyay’s three short stories of the Bengal Famine of 1943, it argues that idioms of left modernity gained a definitive articulation through left political and left cultural movements during the Famine by reducing intricacies of caste struggle into just articulations of class conflict. The discourse of the Famine wrought by artistic and literary practices of the left intellectuals, articulated through realism, represented the Famine as a revolutionary time by formulating a critique of the classist politics of nationalist elites; thereby the discourse of the left recreated class hierarchy in a more complex way than nationalist politics. By constituting the lower castes as an ambiguous monolithic peasant class, however, the middle-class intelligentsia of the left reconfigured the rhetoric of modernity animated by their own caste position within the language of class.