toughness index
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2022 ◽  
Vol 1048 ◽  
pp. 345-358
Author(s):  
A. Kumar Suresh ◽  
M. Muthukannan ◽  
A.D.K.B. Irene ◽  
K. Kumar Arun ◽  
A. Chithambar Ganesh

The flexural behavior of Incinerated Bio-Medical Waste Ash (IBWA) – Ground Granulated Blast Furnace Slag (GGBS) based Reinforced Geopolymer Concrete (RGPC) beams with Waste Glass Powder (WGP) as fine aggregate is explored in this research. The fine aggregate (M-Sand) is substituted by varying the waste glass powder as 0 percent, 5 percent, 10 percent, 15 percent, 20 percent, 25 percent, 30 percent, 35 percent, 40 percent, 45 percent, and 50 percent, and the mixture is cured under atmospheric curing. The impact of the WGP weight percentage on the flexural behavior of GPC beams is analyzed. The conduct of RGPC beams varies from that of ordinary Portland Concrete (OPC) beams, which is defined and examined. Deflection, ductility factor, flexural strength, and toughness index were measured as flexural properties for beams. In contrast to the reference beams, the RGPC beams containing 50% Waste Glass Powder as fine aggregate demonstrated a major increase in cracking resistance, serviceability, and ductility, according to the experimental finding. The RGPC beam without WGP ended in failure with a brittle manner whereas those beams with WGP encountered ductile failure. The RGPC beams' load ability improved by up to 50% as the weight percentage of WGP was enhanced.


2022 ◽  
Vol 1048 ◽  
pp. 333-344
Author(s):  
K. Kumar Arun ◽  
M. Muthukannan ◽  
R. Raja Abinaya ◽  
A. Kumar Suresh

On the demand of reducing the global warming due to cement production which is used as main constituent in the production of concrete and minimizing the environmental impact caused by the waste and its disposal methods, this study was aimed. This study looked in to detail insight view on effective utilization of waste wood ash in the production of geopolymer concrete beams and columns to alternate the conventional reinforced concrete elements in construction industry. Waste wood ash is a waste by product produced in the nearby hotel and factories by burning the waste wood collected from timber industries and the ash are thrown in to land which creates a major environmental pollution. Geopolymer is a novel inorganic eco-friendly binding agent derived from alkaline solution that stimulates aluminosilicate source material (such as metakaolin, fly ash and GGBS). In this research, behaviour of beams in deflection, ductility factor, flexural strength and toughness index and columns in load carrying ability, stress strain behaviour and load-deflection behaviours were examined for three types of concretes (30% WWA – 70% Fly ash Geo-polymer concrete, Fly ash Geo-polymer concrete and Reinforced Cement Concrete). The results showed that inclusion of waste wood ash in geopolymer concrete helped in enhancing the load carrying capacity of beam and column by 42% and 28%. Further, the behaviour of structural elements in stiffness, ductility and toughness were also improved with the replacement of waste wood ash.


2022 ◽  
Vol 1048 ◽  
pp. 321-332
Author(s):  
A. Kumar Suresh ◽  
M. Muthukannan ◽  
R. Kanniga Devi ◽  
K. Kumar Arun ◽  
Ganesh A. Chithambar

This study aims to analyze the use of Incinerated Bio-Medical Waste Ash (IBWA) in reinforced concrete structural member with ground granulated blast furnace slag (GGBS) as an alternate building ingredient instead of cement. Biomedical waste was produced from various medical resources such as hospitals, medical institutes and research centres. GGBS is the waste generated from the steel plant. The climate is now being affected by the release of CO2 (global warming) from the Portland cement industries. Therefore, greater attention must be paid to study efforts to use geopolymer concrete. Geopolymer is a novel inorganic eco-friendly binding agent derived from an alkaline solution that stimulates aluminosilicate source material (GGBS, Rice Husk Ash, Quartz Powder, metakaolin, fly ash and Silica Fume). In this research, laboratory tests for Reinforced Geopolymer Concrete (RGPC) beams (deflection, ductility factor, flexural strength and toughness index) and columns (load-carrying ability, stress-strain behaviour and load-deflection behaviour) were conducted for three types of proportions using [30% IBWA – 70% GGBS Geopolymer concrete, GGBS Geopolymer concrete and Reinforced Cement Concrete. The experimental findings revealed that the performance of reinforced 30% IBWA – 70% GGBS geo-polymer beams and columns worked more effectively than reinforced cement concrete beams and columns.


2021 ◽  
Vol 12 (1) ◽  
pp. 63
Author(s):  
Ahsan Afraz ◽  
Majid Ali

Currently, banana fiber composites have received wide attention because of their ecofriendly properties. The overall aim of this study is to prove banana fiber as an eco-efficient construction material by checking the behavior of banana fiber-reinforced concrete during flexural loading. The length of fiber is kept 50 mm and a fiber content of 5% by the weight of cement was used for preparing banana fiber reinforced concrete. It is shown from the results that the flexural toughness index (FTI) that has a vital role in sustainable concrete increased while the modulus of rupture (MOR) of banana fiber reinforced concrete decreased as compared to ordinary concrete.


2021 ◽  
Vol 13 (19) ◽  
pp. 10748
Author(s):  
Nayara Malheiros Caruzzo ◽  
João Ricardo Nickenig Vissoci ◽  
Andressa Ribeiro Contreira ◽  
Aryelle Malheiros Caruzzo ◽  
Lenamar Fiorese

For a long time, competitive sport has focused only on aspects related to performance. However, studies in social psychology have indicated the importance of focusing on the human development of athletes, which can occur through training environments that promote psychological well-being. Thus, this study aimed to analyze the impact of the coach-athlete attachment style, mediated by the coach’s leadership style, on the mental toughness of athletes in the world beach volleyball context. Elite beach volleyball athletes (n = 65), participants of the World Tour 2018, were part of the study. The Coach-Athlete Attachment Scale (CAAS), Mental Toughness Index (MTI) and Leadership Scale for Sport (LSS) were used as instruments. For data analyses we used polychoric correlation and a bias-corrected factor score path analysis. Path analysis showed that perceived secure attachment was positively associated with athletes’ mental toughness (0.24; 0.31; 0.25), but leadership styles did not mediate this relationship. For athletes with anxious attachment profiles, the perception of autocratic leadership style was associated with athletes’ mental toughness (1.01; p = 0.03), when their interaction style is focused on coaching-instruction. It concludes that the secure attachment relationship can bring increases in levels of athletic mental toughness, whereas for athletes with insecure attachment, the autocratic style was shown to be associated with the highest levels of mental toughness.


Retos ◽  
2021 ◽  
Vol 43 ◽  
pp. 643-650
Author(s):  
Andreas Stamatis ◽  
Grant B. Morgan ◽  
Pedro Julián Flores ◽  
Lenin Tlamatini Barajas Pineda ◽  
Adriana Isabel Andrade Sánchez ◽  
...  

 La fortaleza mental (MT) es un tema ampliamente indagado y relacionado con profesiones, personalidades y la actividad deportiva. El trabajo del psicólogo del deporte es apoyar en el manejo de emociones, el afrontamiento a estresores y establecimiento de metas, haciendo uso de las características multiculturales de los deportistas. Se examinó la invariancia de MT entre atletas estadounidenses y mexicanos a través de la prueba de invarianza, mediante análisis factorial confirmatorio de grupos múltiples con modelos cada vez más restrictivos. El ajuste de los datos del modelo en ambas muestras fue satisfactorio (CFI mexicano = .988, RMSEA mexicano = .085; CFI US = .998, RMSEA US = .032). El modelo de invariancia escalar se seleccionó como el mejor ajuste (escalar CFI = .981, escalar RMSEA = .077). Los resultados implican que el significado del constructo es igual en ambas culturas y sus puntajes pueden compararse directamente.  Abstract. Mental toughness (TM) is a widely investigated topic related to professions, personalities and sports activity. The work of the sports psychologist is to support the management of emotions, coping with factors and setting goals, making use of the multicultural characteristics of athletes. The invariance of TM was examined between American and Mexican athletes through the invariance test. It was performed by confirmatory factor analysis of multiple groups with increasingly restrictive models. The fit of the model data in both samples was very good (Mexican CFI = .988, Mexican RMSEA = .085; US CFI = .998, US RMSEA = .032). The scalar invariance model was selected as the best fit (CFI scalar = .981, RMSEA scalar = .077). The results imply that the meaning of the construct is the same in both cultures and its scores can be directly compared.


Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3169
Author(s):  
Hu Feng ◽  
Yang Wang ◽  
Aofei Guo ◽  
Xiangyu Zhao

In this study, the compressive test and four-point flexural test were carried out to explore the water stability as well as mechanical properties of high ductility magnesium phosphate cement-based composites (HDMC). The effects of ambient curing age (7 d and 28 d), water immersion age (7 d, 28 d, and 56 d), water/binder ratio (W/B), and magnesium oxide/potassium dihydrogen phosphate ratio (M/P) on the mechanical properties (compressive strength, first-crack strength, ultimate flexural strength, ductility index, and toughness index) and water stability of the HDMC were examined. The results showed that the 28-day ambient curing could lead to higher retention rates of strength, ductility, and toughness than 7-day ambient curing, indicating better water stability; however, it did not result in significant improvement in the mechanical properties of the HDMC. As the water immersion age increased, the mechanical properties of the HDMC with 7-day ambient curing showed an obvious downward trend; the mechanical properties of the HDMC with 28-day ambient curing did not show an obvious decrease and even could be increased in many cases, especially when the water immersion age was 56 days; and the change of water stability was consistent with that of the mechanical properties. If all indexes and their corresponding retention rates were considered comprehensively, the W/B ratio of 0.16 and the M/P ratio of 5 seemed to be the optimum values for the HDMC. The scanning electron microscopy analysis confirmed that the water immersion had a large adverse effect on the HDMC and thus reduced their mechanical properties.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1257
Author(s):  
Shuling Gao ◽  
Guanhua Hu

An improved hydraulic servo structure testing machine has been used to conduct biaxial dynamic compression tests on eight types of engineered cementitious composites (ECC) with lateral pressure levels of 0, 0.125, 0.25, 0.5, 0.7, 0.8, 0.9, 1.0 (the ratio of the compressive strength applied laterally to the static compressive strength of the specimen), and three strain rates of 10−4, 10−3 and 10−2 s−1. The failure mode, peak stress, peak strain, deformation modulus, stress-strain curve, and compressive toughness index of ECC under biaxial dynamic compressive stress state are obtained. The test results show that the lateral pressure affects the direction of ECC cracking, while the strain rate has little effect on the failure morphology of ECC. The growth of lateral pressure level and strain rate upgrades the limit failure strength and peak strain of ECC, and the small improvement is achieved in elastic modulus. A two-stage ECC biaxial failure strength standard was established, and the influence of the lateral pressure level and peak strain was quantitatively evaluated through the fitting curve of the peak stress, peak strain, and deformation modulus of ECC under various strain rates and lateral pressure levels. ECC’s compressive stress-strain curve can be divided into four stages, and a normalized biaxial dynamic ECC constitutive relationship is established. The toughness index of ECC can be increased with the increase of lateral pressure level, while the increase of strain rate can reduce the toughness index of ECC. Under the effect of biaxial dynamic load, the ultimate strength of ECC is increased higher than that of plain concrete.


PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244579
Author(s):  
Andreas Stamatis ◽  
Paul J. Deal ◽  
Grant B. Morgan ◽  
Jeffrey S. Forsse ◽  
Zacharias Papadakis ◽  
...  

Recent tragic events and data from official NCAA reports suggest student-athletes' well-being is compromised by symptoms of mental health (MH) disorders. Self-compassion (SC) and mental toughness (MT) are two psychological constructs that have been shown effective against stressors associated with sports. The purpose of this study was to investigate SC, MT, and MH in a NCAA environment for the first time and provide practical suggestions for MH best practice No.4. In total, 542 student-athletes participated across Divisions (Mage = 19.84, SD = 1.7). Data were collected through Mental Toughness Index, Self-Compassion Scale, and Mental Health Continuum–Short Form. MT, SC (including mindfulness), and MH were positively correlated. Males scored higher than females on all three scales. No differences were found between divisions. SC partially mediated the MT-MH relationship, but moderation was not significant. Working towards NCAA MH best practice should include training athletes in both MT and SC skills (via mindfulness).


Author(s):  
Samiullah Qazi

The plastic existence in abundance and its low biodegradability affect the environment. In recent years, researchers have tested numerous recycling techniques. However, each has its demerits. One such technique is recycling plastic as aggregates in concrete. It improves the concrete thermal insulation but depreciates its compressive and tensile strength, which is its core property in the construction industry. The objective of this research work is to efficiently utilize the plastic aggregate in concrete without deteriorating its strength with the use of steel fibers. In total eight concrete mix configurations were studied in this research. The result discussion includes compressive strength, split tensile test, and toughness index. The steel fiber used in the concrete mix with recycled plastic as fine aggregates improved the concrete strength. Its effects increase with an increase in % vol replacement of plastic aggregates with fine aggregates from 5 to 20.


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