Study on Concrete's Temperature Control Measures for Inverted-Siphons during Construction Period

2012 ◽  
Vol 443-444 ◽  
pp. 792-795
Author(s):  
Xiao Mei Dong ◽  
Yi He ◽  
Jing Chao Sun
Keyword(s):  
Temperature Control ◽  
Concrete Surface ◽  
Control Measures ◽  
Good Effect ◽  
Construction Period ◽  
Inverted Siphon ◽  
Time Space ◽  
North Water ◽  
Water Pipe Cooling

In view of the problem of concrete cracks during construction, the good effect of cracks prevention can be achieved if the timely and reasonable scheme of temperature control is selected. Under the 3-D FEM including water-pipe cooling is adopted to simulate the stresses field of Inverted siphon during construction. Through analyzing the time-space variation law, it is fund that cracks easily appear. In the part of the middle line of the South-North Water Transfer Project£¬the quality of concrete surface of III section in Jiaozuo has been improved obviously through the method of external insulation board.

Study on Concrete's Temperature Control Measures for Inverted-Siphons in Wenxian-Boai I Section

2012 ◽  
Vol 443-444 ◽  
pp. 788-791
Author(s):  
Yi He ◽  
Xiao Mei Dong ◽  
Chen Hui Zheng
Keyword(s):  
Concrete Surface ◽  
Control Measures ◽  
Mass Concrete ◽  
External Temperature ◽  
External Insulation ◽  
Inverted Siphon ◽  
Time Space ◽  
North Water ◽  
The Difference

In view of the problem of mass concrete cracks during construction, the corresponding measures and methods are put forward. Generally speaking, the difference between the internal and external temperature and the basic difference of temperature are considered as the main factors influencing the phenomena. Under the FEM is adopted to simulate the stresses field of Inverted siphon during construction. Through analyzing the time-space variation law, it is fund that cracks easily appear. In the part of the middle line of the South-North Water Transfer Project£¬the quality of concrete surface of ¢ñsection in Jiaozuo has been improved obviously through the method of external insulation board, so it deserves to bepopularized.

Study on Crack Prevention Measures of Mass RCC Dams

2013 ◽  
Vol 743 ◽  
pp. 3-8
Author(s):  
Jian Guo Jing ◽  
Min Zhi Liu ◽  
Shao Jun Zeng ◽  
Lin Xu
Keyword(s):  
Temperature Control ◽  
Control Measures ◽  
Simple Construction ◽  
Prevention Measures ◽  
Construction Period ◽  
The Way

Actually, both simple construction and fast construction are advantages of RCC dams. In view of taking strict temperature control measures, those are turned to be disadvantages instead. The way of fast pouring and the measure of controlling the placing temperature are introduced to RCC dams and 6 cases are analyzed separately to explain the effect of their crack prevention. It is concluded that controlling only the last layer placing temperature of concrete lifts can remarkably decrease the stress of working plane concrete during off period. Furthermore, the pouring way of thick lifts and short off period do not deteriorate the temperature and stress but rather has an impressive effect on crack prevention and construction period contraction.

A New Method for Improving the Stress Status of the Dam

2013 ◽  
Vol 444-445 ◽  
pp. 849-853
Author(s):  
Jian Hua Cui ◽  
Yong Feng Qi ◽  
Jie Su
Keyword(s):  
Temperature Control ◽  
Cooling Water ◽  
Control Measures ◽  
Sensitivity Analyses ◽  
Mass Concrete ◽  
Water Cooling ◽  
Concrete Gravity Dam ◽  
3D Fem ◽  
Construction Period ◽  
Operation Period

Under the action of annual change and sudden drop of air temperature, thermal induced cracking will occur in concrete dam during the operation period. For exploring the temperature control measures for crack prevention, taking a concrete gravity dam section as the research object, sensitivity analyses to the factors which affecting the water-cooling effect are conducted with 3D FEM, some significant suggestions for the water cooling are presented. The results show that, the stresses of the dam surface will decrease to a certain extent after water cooling in the operation period using the cooling water pipe which embedded during construction period, and the cracking risk of the dam will reduce. The study provides a new train of thought for the temperature control and crack prevention of the mass concrete during the operation period.

Influence of Water Pipe Cooling on Thermal Stresses in Mass Concrete

2011 ◽  
Vol 137 ◽  
pp. 12-15
Author(s):  
Xin Li Bai ◽  
Ze Yu Wu ◽  
Wen Liang Ma ◽  
Dan Fei Wang
Keyword(s):  
Temperature Control ◽  
Thermal Stresses ◽  
Early Period ◽  
Control Measures ◽  
Mass Concrete ◽  
Late Period ◽  
Water Pipe ◽  
Effective Measure ◽  
Influence Of Water ◽  
Water Pipe Cooling

Temperature field and stress field of a concrete slab in a ship lock chamber are calculated, considering the influence of layered casting. And the influence of water pipe cooling at the early period of constructing, and at the period after constructing, sunshade, pre-cooled concrete etc are taken into account. The expression of finite difference method considering the effect of water pipe cooling is deducted for temperature analysis. Thermal stress calculation results show that the water pipe cooling at the mid-late period is a comparatively effective measure to reduce tensile stress of chamber mass concrete. And an effective temperature control measure is recommended in summer casting, which is that: sunshade + pre-cooled concrete + water pipe cooling (both at early period and at mid-late period). Mid-late period water pipe cooling must last for three months. Combined with other temperature control measures such as summer cover maintenance, winter cover preservation etc, the concrete cracks can be reduced, and the occurrence of large area run through cracks can be avoided.

Study on Crack Prevention for Concrete Rapid Construction

2011 ◽  
Vol 291-294 ◽  
pp. 1149-1153 ◽  
Author(s):  
Min Zhi Liu ◽  
Sheng Qiang ◽  
Bing Lei Wang ◽  
Zhan Qiang Zhen ◽  
Xiang Rong Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Temperature Control ◽  
Control Measures ◽  
3D Finite Element ◽  
Time Space ◽  
Rapid Construction ◽  
Thin Walled ◽  
3D Finite Element Method ◽  
Element Method

Pier concrete is vulnerable to cracking when using concrete rapid construction after long off period. In order to solve this problem, crack mechanism and effects of several temperature control measures of thin-walled structure concrete is analyzed. Through analyzing the temperature and stress time-space variation using 3D finite element method, it can be found that stress is more sensitive to controlling concrete placing temperature than other measures. It also shows that under the condition of taking other proper temperature control measures, low placing temperature can not be spared.

Simulation Analysis of Plain Sluice Concrete Temperature and Stress

2013 ◽  
Vol 438-439 ◽  
pp. 583-587
Author(s):  
Kai Yun Yang ◽  
Fei Guo ◽  
Lin Hao Li
Keyword(s):  
Temperature Control ◽  
Concrete Structure ◽  
Simulation Analysis ◽  
Model Simulation ◽  
Element Model ◽  
Control Measures ◽  
Construction Period ◽  
Windy Weather ◽  
Cracking Risk ◽  
The Finite Element Model

For sluice concrete structure is more complex due to constrained by the base effect and upper structures, with the purpose of temperature control, we carry out the simulation analysis of temperature and stress during the construction of pier concrete structure. Taking a sluice project as an example, use the method developed by Thermo finite subspace model simulation procedures, the finite element model of pier structure is built with high precision. The results show that the cracking risk is relatively small and prone to surface cracks for baseplate; during construction period, much more attention should be payed to the high temperature difference between day and night, and to the insulation work at cold and windy weather; the key problem is that the middle pier which faces relatively great cracking risk, and necessary temperature control measures should be adopted.

Assessment of quality of life in patients with the effects of transient ischemic stroke

2016 ◽  
pp. 37-39
Author(s):  
A. Babirad
Keyword(s):  
Quality Of Life ◽  
Ischemic Stroke ◽  
Large Scale ◽  
Cerebrovascular Diseases ◽  
Control Measures ◽  
Sociological Research ◽  
Cerebrovascular Events ◽  
Sf 36 ◽  
Angioplasty And Stenting

Cerebrovascular diseases are a problem of the world today, and according to the forecast, the problem of the near future arises. The main risk factors for the development of ischemic disorders of the cerebral circulation include oblique and aging, arterial hypertension, smoking, diabetes mellitus and heart disease. An effective strategy for the prevention of cerebrovascular events is based on the implementation of large-scale risk control measures, including the use of antiagregant and anticoagulant therapy, invasive interventions such as atheromectomy, angioplasty and stenting. In this connection, the efforts of neurologists, cardiologists, angiosurgery, endocrinologists and other specialists are the basis for achieving an acceptable clinical outcome. A review of the SF-36 method for assessing the quality of life in patients with the effects of transient ischemic stroke is presented. The assessment of quality of life is recognized in world medical practice and research, an indicator that is also used to assess the quality of the health system and in general sociological research.

scholarly journals Studies on the Occurrence of Viruses in Planting Material of Grapevines in Southwestern Germany

Viruses ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 248
Author(s):  
Noemi Messmer ◽  
Patricia Bohnert ◽  
Stefan Schumacher ◽  
René Fuchs
Keyword(s):  
Preventive Measures ◽  
Control Measures ◽  
Grapevine Fanleaf Virus ◽  
Arabis Mosaic Virus ◽  
Planting Material ◽  
General Decline ◽  
Grapevine Pinot Gris Virus ◽  
Propagation Material

Viral diseases in viticulture lead to annual losses in the quantity and quality of grape production. Since no direct control measures are available in practice, preventive measures are taken to keep the vines healthy. These include, for example, the testing of propagation material for viruses such as Arabis mosaic virus (ArMV), Grapevine fanleaf virus (GFLV) or Grapevine leafroll-associated virus 1 (GLRaV-1) and 3 (GLRaV-3). As long-term investigations have shown, GLRaV-1 (2.1%) occurs most frequently in southwestern German wine-growing regions, whereas GLRaV-3 (<0.1%) is almost never found. However, tests conducted over 12 years indicate that there is no general decline in virus-infected planting material. Thus, it can be assumed that a spread of the viruses via corresponding vectors still takes place unhindered. Beyond the examinations regulated within the German Wine Growing Ordinance, one-time tests were carried out on Grapevine Pinot gris virus (GPGV). This analysis showed that GPGV was found in 17.2% of the samples.

scholarly journals Research on concrete temperature control measures in deep hole area of super high arch dam

2021 ◽  
Vol 826 (1) ◽  
pp. 012035
Author(s):  
Yuchen Fu ◽  
Yaosheng Tan ◽  
Chunfeng Liu ◽  
Lei Pei ◽  
Yajun Wang ◽  
...  
Keyword(s):  
Temperature Control ◽  
Arch Dam ◽  
Control Measures ◽  
Deep Hole ◽  
High Arch Dam ◽  
Hole Area ◽  
Concrete Temperature

scholarly journals Understanding contributors to quality of care in long-term care and changes under COVID-19

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 960-960
Author(s):  
Sara Luck ◽  
Katie Aubrecht
Keyword(s):  
Quality Of Care ◽  
Long Term Care ◽  
The United States ◽  
Control Measures ◽  
Qualitative Description ◽  
Care Staff ◽  
Term Care ◽  
The Impact

Abstract Nursing home facilities are responsible for providing care for some of the most vulnerable groups in society, including the elderly and those with chronic medical conditions. In times of crisis, such as COVID-19 or other pandemics, the delivery of ‘regular’ care can be significantly impacted. In relation to COVID-19, there is an insufficient supply of personal protective equipment (PPE) to care for residents, as PPE not only protects care staff but also residents. Nursing homes across the United States and Canada have also taken protective measures to maximize the safety of residents by banning visitors, stopping all group activities, and increasing infection control measures. This presentation shares a research protocol and early findings from a study investigating the impact of COVID-19 on quality of care in residential long-term care (LTC) in the Canadian province of New Brunswick. This study used a qualitative description design to explore what contributes to quality of care for residents living in long-term care, and how this could change in times of crisis from the perspective of long-term care staff. Interviews were conducted with a broad range of staff at one LTC home. A semi-structured interview guide and approach to thematic analysis was framed by a social ecological perspective, making it possible to include the individual and proximal social influences as well as community, organizations, and policy influencers. Insights gained will improve the understanding of quality of care, as well as potential barriers and facilitators to care during times of crisis.

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