Influence of the Aggregate Type on the Properties of Dolomitic Lime-Based Mortars

2016 ◽  
Vol 722 ◽  
pp. 343-350 ◽  
Author(s):  
Martin Vyšvařil ◽  
Tomáš Žižlavský ◽  
Patrik Bayer
Keyword(s):  
Positive Impact ◽  
Total Porosity ◽  
Strength Properties ◽  
Carbonation Reaction ◽  
Dolomitic Lime ◽  
Limestone Aggregate ◽  
Lime Mortars ◽  
Restoration Work ◽  
Limestone Fines

Considering the requirement of numerous restoration work on historical buildings with dolomitic lime-based mortars, a research of the applicability and suitability of various types of plasters for repairing the historical plasters have been developed. This work presents the applicability of limestone aggregate and limestone fines to dolomitic lime-based mortars. The role of aggregates on the properties of dolomitic lime mortars was examined by comparing pure quartz sand and limestone aggregate and its quantity in the mortar. Limestone aggregate and limestone fines accelerated the carbonation reaction in the mortars, but the positive impact of limestone aggregates to strength properties of mortars was not observed. Mortars with limestone aggregate showed higher total porosity and water absorption than those with quartz aggregate. Similar results was obtained for mortars with limestone fines. It was found that limestone aggregate and limestone fines, used in this work, is not so suitable and applicable to the dolomitic lime-based mortar as to the aerial lime-based mortars.

The Effect of Aggregate Type on the Properties of Lime Mortars

2016 ◽  
Vol 861 ◽  
pp. 141-148 ◽  
Author(s):  
Martin Vyšvařil ◽  
Tomáš Žižlavský ◽  
Patrik Bayer
Keyword(s):  
Mechanical Properties ◽  
Absorptive Capacity ◽  
Building Materials ◽  
Historical Buildings ◽  
Limestone Aggregate ◽  
Lime Mortars ◽  
Restoration Work ◽  
Limestone Fines ◽  
Dramatic Growth

Lime mortars represent indispensable building materials that have been used for centuries in civil engineering. Considering the necessity of numerous restoration work on historical buildings, a research of the applicability and suitability of various types of plasters for repairing the historical plasters has been developed. This work presents the applicability of limestone aggregate and limestone fines to aerial lime-based mortars. The role of aggregates on the properties of lime mortars is examined in this paper by comparing pure quartz sand and limestone aggregate and its quantity in the mortar. It was found that limestone aggregate produced the comparable or higher mortar strengths than quartz aggregate and slightly increased porosity, water absorptive capacity and carbonation rate of the mortars. Partially replacement of aggregate by limestone fines has caused dramatic growth in strength, especially in mortars with high content of binder. The applied limestone aggregate is convenient to lime-based mortars and the addition of limestone fines contributes to better mechanical properties of lime mortars.

scholarly journals Towards a better understanding of hot-mixed mortars for the conservation of historic buildings: the role of water temperature and steam during lime slaking

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Cecilia Pesce ◽  
Martha C. Godina ◽  
Alison Henry ◽  
Giovanni Pesce
Keyword(s):  
Water Temperature ◽  
Water Retention ◽  
Strength Properties ◽  
X Ray Diffraction ◽  
Mineralogical Characteristics ◽  
Slaked Lime ◽  
Lime Mortars ◽  
Restoration Work ◽  
Material Evidence

AbstractAccording to various historic accounts and material evidence, the practice of producing lime mortars by mixing the quicklime with the sand (i.e. hot-mixing) before first slaking it with water was much more common in the past centuries than appreciated by most contemporary academics, conservation professionals and craftsmen. However, in the last 10 years, there has been resurgence in interest in hot-mixing. In such systems, the steam developed during the mixing is supposed to be crucial in determining the superior characteristics of the mortars, but in-depth investigations on the role of steam in hot-mixing are very few. This study reports the results of some experimental work investigating the effects of water temperature and steam used for lime slaking on the characteristics of lime and related mortars. In these tests, calcic quicklime was slaked in water at 20 and 75 °C, and with steam at 90 °C. Microstructure and mineralogical characteristics of the hydrates were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Mortars produced with these limes were tested for fresh (water retention and flowability) and hardened (compressive and flexural strength) properties. Carbonation was assessed using SEM, XRD and phenolphthalein tests. Results show that steam-slaked lime is characterised by portlandite crystals with smaller crystallite size and significantly different microstructure compared to that of water-slaked lime. Results also show that mortars made with steam-slaked lime have higher water retention and flowability than the mortars produced with water-slaked lime. Under conditions of comparatively low relative humidity (c 40–50%), carbonation is slower in the steam-slaked lime mortar due to the lower water content compared to water-slaked lime mortars. Overall, these results confirm anecdotal reports of better workability and water retention and suggest that this production technology, which is only rarely used nowadays, can produce mortars with improved characteristics, and provide a means by which to match the performance of some historic mortars, and create compatible materials for conservation and restoration work.

Effect of Aggregate Type on Properties of Natural Hydraulic Lime-Based Mortars

2017 ◽  
Vol 908 ◽  
pp. 35-39 ◽  
Author(s):  
Martin Vyšvařil ◽  
Tomáš Žižlavský ◽  
Štěpán Zimmermann ◽  
Patrik Bayer
Keyword(s):  
Frost Resistance ◽  
Total Porosity ◽  
Hydraulic Lime ◽  
Limestone Aggregate ◽  
Natural Hydraulic Lime ◽  
Detailed Characteristic ◽  
Restoration Practice ◽  
Limestone Fines ◽  
Mechanical Strengths

In the current restoration practice, the mortars based on aerial or hydraulic lime with siliceous aggregate are used on repair / reconstruction of historical plasters. The resulting properties of lime mortars do not depend only on the type of aggregate, but also on its contamination, origin and a degree of hardening. For this reason, it is needed to know a detailed characteristic of the aggregate and the results obtained for the particular aggregate cannot be generally applied for the similar type of aggregate. This work presents the applicability of Czech local crushed limestone aggregate and limestone fines as a filler to natural hydraulic lime-based mortars. The role of aggregate and limestone fines on the properties of mortars is examined by comparing the mechanical strengths, porosity and frost resistance of the mortars with pure quartz sand and limestone aggregate and its quantity in the mortar. It was found that the limestone aggregate has produced lower strengths, higher total porosity of natural hydraulic lime-based mortars. It has resulted in low frost resistance of the mortars.

SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

1977 ◽  
Vol 35 ◽  
pp. 308-309
Author(s):  
K. W. Robinson
Keyword(s):  
Tension Wood ◽  
Wood Fiber ◽  
Strength Properties ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Pure Cellulose ◽  
Short Rotation ◽  
Hardwood Trees ◽  
Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

Potential effect of pharmaceutical care to improve outcomes in patients with chronic kidney disease-mineral bone disorder in Sulaimani dialysis centers

2020 ◽  
pp. 82-94
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Pharmaceutical Care ◽  
Biochemical Parameters ◽  
Positive Impact ◽  
Potential Effect ◽  
Care Group ◽  
Mineral Bone Disorder ◽  
Bone Disorder

Objective: the present study was aimed to evaluate the role of pharmaceutical services in improving the outcome of mineral bone disorder in patients with advanced chronic kidney disease. Methodology: One hundred and twenty patients with chronic kidney disease-mineral bone disorder (CKD-MBD) screened for eligibility, seventy-six patients enrolled in the study and randomly allocated into two groups: pharmaceutical care and usual care, both groups interviewed by the pharmacist using specific questionnaire for assessing the quality of life (QoL). All the drug related problems (DRPs) including drug-drug interactions (DDIs) were recorded by the pharmacist. Blood samples were collected and utilized for analyzing the levels of vitamin D, phosphorous, calcium, albumin and parathyroid hormone at baseline and three months after. The pharmaceutical care group received all the educations about their medications and how to minimize DRPs; improve the QoL. Additionally, the pharmaceutical intervention included correcting the biochemical parameters. Results: Pharmaceutical care significantly improved patients QoL and minimized DRPs and DDIs. It was also effective in improving the biochemical parameters. Conclusion: Pharmaceutical care has a positive impact on improving the outcome of patients with CKD-MBD through attenuating DRPs, improving the biochemical parameters and the QoL.

Strategic Role of Zakat in Multidimensional Quality of Life in Sijunjung, Indonesia

2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal
Keyword(s):  
Quality Of Life ◽  
Positive Impact ◽  
Wealth Distribution ◽  
Absolute Poverty ◽  
Before And After ◽  
The Status ◽  
Being There ◽  
The Impact

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.

Employees’ Motivation for Creating International Business Venture: The Role of Perceived Competence and Job Satisfaction

2020 ◽  
Vol 25 (2) ◽  
Author(s):  
Anh D. Pham ◽  
Men T. Bui ◽  
Dung P. Hoang
Keyword(s):  
Job Satisfaction ◽  
International Business ◽  
Structural Equation ◽  
Positive Impact ◽  
Entrepreneurial Intention ◽  
Perceived Competence ◽  
Equation Model ◽  
Network Building ◽  
Perceived Desirability

This research investigates the determinants of entrepreneurial intention among Vietnamese employees, a crucial segment of potential entrepreneurs yet mostly neglected in previous studies. Given the focus on intention to create an international business venture and the working segment, we expand the entrepreneurial event theory by supplementing perceived competence and job satisfaction as determinants of entrepreneurial intention while testing the mediation of perceived feasibility and perceived desirability in such relationships correspondingly. Three focus groups on 27 Vietnamese employees were conducted to explore the specific relevant competences and develop the conceptual model. Afterwards, data from an empirical survey on 567 Vietnamese employees was analysed using a partial least squares structural equation model to test the hypothesised relationships. The empirical results indicate that perceived competences, viz. administrative competence, communication skills, network building competence, and international business expertise have a positive impact on entrepreneurial intention. The relationships between either administrative competence, network building capacity or international business expertise, and entrepreneurial intention are totally mediated by perceived feasibility. The study also reveals a noteworthy finding about the negative direct effect of overall job satisfaction on entrepreneurial intention and the partial mediating role of perceived desirability in this relationship.

scholarly journals The Prognostic and Predictive Role of Somatic BRCA Mutations in Ovarian Cancer: Results from a Multicenter Cohort Study

Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 565
Author(s):  
Angela Toss ◽  
Claudia Piombino ◽  
Elena Tenedini ◽  
Alessandra Bologna ◽  
Elisa Gasparini ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Positive Impact ◽  
Progression Free Survival ◽  
Molecular Testing ◽  
Wild Type ◽  
Brca Mutations ◽  
Multicenter Cohort Study ◽  
Advanced Stages ◽  
Predictive Role

Previous research involving epithelial ovarian cancer patients showed that, compared to germline BRCA (gBRCA) mutations, somatic BRCA (sBRCA) mutations present a similar positive impact with regard to overall survival (OS) and platinum and PARP (poly (ADP-ribose) polymerase) inhibitor sensitivity. Nevertheless, molecular testing in these studies did not include copy number variation (CNV) analyses of BRCA genes. The aim of this study was to explore the prognostic and predictive role of sBRCA mutations as compared to gBRCA mutations in patients who were also tested for CNVs. Among the 158 patients included in the study, 17.09% of patients carried a pathogenic or likely pathogenic gBRCA variant and 15.19% of patients presented pathogenetic or likely pathogenic sBRCA variants and/or CNVs. Overall, 81.6% of the patients included in this study were diagnosed with a serous histotype, and 77.2% were in advanced stages. Among women diagnosed in advanced stages, gBRCA patients showed better progression-free survival and OS as compared to sBRCA and wild-type patients, whereas sBRCA patients did not show any advantage in outcome as compared to wild-type patients. In this study, the introduction of CNV analyses increased the detection rate of sBRCA mutations, and the resulting classification among gBRCA, sBRCA and wild-type patients was able to properly stratify the prognosis of OC patients. Particularly, sBRCA mutation patients failed to show any outcome advantage as compared to wild-type patients.

scholarly journals Resident-Tourist Value Co-Creation in the Intangible Cultural Heritage Tourism Context: The Role of Residents’ Perception of Tourism Development and Emotional Solidarity

2021 ◽  
Vol 13 (3) ◽  
pp. 1369
Author(s):  
Tianning Lan ◽  
Zhiyue Zheng ◽  
Di Tian ◽  
Rui Zhang ◽  
Rob Law ◽  
...  
Keyword(s):  
Cultural Heritage ◽  
Positive Impact ◽  
Heritage Tourism ◽  
Tourism Development ◽  
Intangible Cultural Heritage ◽  
Mediating Role ◽  
Local Residents ◽  
Emotional Solidarity ◽  
Cultural Heritage Tourism

The value co-creation behavior of residents can contribute to the sustainable development of intangible cultural heritage (ICH) tourism. This paper aims to provide a theoretical framework that uses “cognition–affection–behavior” theory to explain how the two variables of tourism development perception and emotional solidarity affect the value co-creation participation behavior of the local residents in the context of intangible cultural heritage tourism while considering the mediating role of emotional solidarity. This study empirically investigates Meizhou Island in Fujian Province, China as an example by using a structural equation model (SEM). Results show that the perception of local residents toward the benefits of tourism development has a significant positive impact on their emotional solidarity and value co-creation participation behavior, whereas their perception toward the costs of tourism development has a significant negative impact. In addition, the emotional solidarity of these residents has a significant positive impact on their value co-creation participation and plays a mediating role in the relationship between the tourism development perceptions of local residents and their value co-creation participation behavior. This study has important theoretical and practical significance for the management of ICH tourist destinations.

scholarly journals Exploring the Relationship between Communication and Success of Construction Projects: The Mediating Role of Conflict

2021 ◽  
Vol 13 (8) ◽  
pp. 4513
Author(s):  
Summaira Malik ◽  
Muhammad Taqi ◽  
José Moleiro Martins ◽  
Mário Nuno Mata ◽  
João Manuel Pereira ◽  
...  
Keyword(s):  
Project Success ◽  
Negative Impact ◽  
Positive Impact ◽  
Construction Project ◽  
Project Team ◽  
Relationship Conflict ◽  
Team Members ◽  
Mediating Role ◽  
The Impact

The success of a construction project is a widely discussed topic, even today, and there exists a difference of opinion. The impact of communication and conflict on project success is an important, but least addressed, issue in literature, especially in the case of underdeveloped countries. Miscommunication and conflict not only hinder the success of a project but also may lead to conflicts. The focus of this paper was to examine the impact of communication on project success with the mediating role of conflict. By using SPSS, demographics, descriptive statistics and correlation were determined. Smart PLS version 3.0 was used for confirmatory factor analysis (CFA), internal accuracy and validity estimates, hypothesis checking and mediation testing. The results showed that formal communication has a negative impact on the success of a construction project, resulting in conflicts among project team members, whereas informal communication and communication willingness have a positive impact on project success because people tend to know each other, and trust is developed. Task, process and relationship conflicts were used as mediating variables. It was found that task conflict effects the relations positively because project team members suggest different ways to do a certain task, and, hence, project success is achieved. On the contrary, process conflict and relationship conflict have a negative impact on communication and project success. Both of these conflicts lead to miscommunication, and project success is compromised. Hence, it is the responsibility of the project manager to enhance communication among project team members and to reduce the detrimental effects of process and relationship conflict on project success.

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