scholarly journals A Review of the Use of UHPFRC in Bridge Rehabilitation and New Construction in Switzerland

2021 ◽  
Vol 7 ◽  
Author(s):  
Numa Bertola ◽  
Philippe Schiltz ◽  
Emmanuel Denarié ◽  
Eugen Brühwiler
Keyword(s):  
Case Studies ◽  
High Performance ◽  
Cost Effective ◽  
Dense Matrix ◽  
Construction Costs ◽  
Construction Time ◽  
Existing Structures ◽  
Bridge Rehabilitation ◽  
Effective Interventions ◽  
First Case

Ultra-High-Performance Fibre Reinforced Cementitious Composite (UHPFRC) provides solutions to enhance existing structures and design innovative new structures. Structural UHPFRC offers 3–5 times higher compressive and tensile strengths than ordinary concrete. Due to its strain-hardening behavior and dense matrix, structures made of UHPFRC remain crack-free and waterproof, guaranteeing durability. UHPFRC has been used particularly in Switzerland with more than 280 applications since 2003. A review of UHPFRC applications in the country is proposed in this paper. Ten bridge case studies are presented, including five strengthening of existing structures and five new designs. These structures were chosen to assess the multiple benefits that UHPFRC provides compared to traditional reinforced-concrete structures. Besides structural efficiency, several construction criteria are considered, such as construction costs, material durability, environmental impacts, and construction time. Structural rehabilitation made with UHPFRC leads to cost-effective interventions, and this material also helps to preserve heritage structures. Due to its specific mechanical properties, UHPFRC enables new structures with distinctive aesthetic designs with reduced construction time. The crucial contribution of research to the first case studies is also highlighted. This link between Swiss universities and the construction industry has quickly transitioned UHPFRC Technology from academic studies to real-world applications. Nowadays, the UHPFRC Technology is maturing and applications are common in the country.

Fatigue Life and Reliability Consideration During Field Repair of Coke Drum and Piping

2017 ◽  
Author(s):  
Tej Chadda ◽  
Umakanthan Anand
Keyword(s):  
Fatigue Life ◽  
Case Studies ◽  
Fatigue Cracks ◽  
High Stress ◽  
Cost Effective ◽  
Thermal Operation ◽  
Delayed Coking ◽  
First Case ◽  
Crack Repair

Aging coke drums and their connected overhead piping in delayed coking units experience fatigue cracks which most commonly occur at the skirt junction and high stress pipe welds. This paper presents 2-case studies of this new cost-effective repair methodology with fatigue resistant design upgrade. The first case study applies to coke drum weld build-up solid skirt crack repair and the second for overhead vapor line weld crack repair. This paper presents new field repair methodology which could also improve long term fatigue resistance. It also suggests optimizing the thermal operation & thermal gradients of coke drums for further reliability improvement. Based on FEA, successful field execution and our experience, these case studies demonstrate a long term improvement in reliability and fatigue life of the order of 2.5 to 3 or higher especially if combined with thermal operation optimization.

scholarly journals Cost-Effective High-Performance Concrete: Experimental Analysis on Shrinkage

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2730
Author(s):  
Barbara Kucharczyková ◽  
Dalibor Kocáb ◽  
Petr Daněk ◽  
Ivailo Terzijski
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Setting Time ◽  
Mechanical Strain ◽  
Cost Effective ◽  
Strain Gauges ◽  
Early Age ◽  
Dry Air ◽  
First Case

This paper focuses on the experimental determination of the shrinkage process in Self-Compacting High-Performance Concrete (SCC HPC) exposed to dry air and autogenous conditions. Special molds with dimensions of 100 mm × 60 mm × 1000 mm and 50 mm × 50 mm × 300 mm equipped with one movable head are used for the measurement. The main aim of this study is to compare the shrinkage curves of SCC HPC, which were obtained by using different measurement devices and for specimens of different sizes. In addition, two different times t0 are considered for the data evaluation to investigate the influence of this factor on the absolute value of shrinkage. In the first case, t0 is the time of the start of measurement, in the second case, t0 is the setting time. The early-shrinkage (48 h) is continuously measured using inductive sensors leant against the movable head and with strain gauges embedded inside the test specimen. To monitor the long term shrinkage, the specimens are equipped with special markers, embedded into the specimens’ upper surface or ends. These markers serve as measurement bases for the measurement using mechanical strain gauges. The test specimens are demolded after 48 h and the long term shrinkage is monitored using the embedded strain gauges (inside the specimens) and mechanical strain gauges that are placed, in regular intervals, onto the markers embedded into the specimens’ surface or ends. The results show that both types of measurement equipment give a similar result in the case of early age measurement, especially for the specimens cured under autogenous conditions. However, the early age and especially long term measurement are influenced by the position of the measurement sensors, particularly in the case of specimens cured under dry air conditions. It was proven that the time t0 have a fundamental influence on the final values of the shrinkage of investigated SCC HPC and have a significant impact on the conclusions on the size effect.

scholarly journals Comparison of Conventional and Advanced Concrete Technologies in terms of Construction Efficiency

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Matej Špak ◽  
Mária Kozlovská ◽  
Zuzana Struková ◽  
Renáta Bašková
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Construction Material ◽  
Ultra High Performance Concrete ◽  
Construction Costs ◽  
Construction Time ◽  
Modern Methods ◽  
Precast Elements ◽  
Monolithic Structures ◽  
Construction Efficiency

Nowadays, high-performance concrete (HPC) and ultra-high-performance concrete (UHPC) are ranked among advanced concrete technologies. The application of the mentioned advanced technologies may have potential to improve the construction efficiency from several points of view. For instance, reducing of construction time and construction material, construction quality improving, environmental impact minimizing, and increasing of both durability and lifetime of structures as well as reducing of total construction costs may be obtained. Particular advanced concrete technologies are described and the possibilities of their utilization in both monolithic structures and precast units are presented in the article. The main benefits of modern methods of construction (MMC) based on advanced concrete technologies application in precast elements production are presented. Regarding the selected aspects of construction efficiency assessment, a comparison of conventional and advanced concrete technologies that are applied in monolithic structures and precast units is made. The results of this comparison, estimated in semantic differential scale, are presented in the article. By the results of the comparison, the significance of applying the advanced concrete technologies in modern methods of concrete structures production is demonstrated in order to improve construction efficiency.

VILLAGE SURVEYS FOR TECHNOLOGY UPTAKE MONITORING: CASE OF TILLAGE DYNAMICS IN THE TRANS-GANGETIC PLAINS

2010 ◽  
Vol 46 (3) ◽  
pp. 277-292 ◽  
Author(s):  
OLAF ERENSTEIN
Keyword(s):  
Case Studies ◽  
Technology Use ◽  
Agricultural Research ◽  
Conservation Agriculture ◽  
Cost Effective ◽  
Conventional Tillage ◽  
Gangetic Plains ◽  
First Case ◽  
Northwest India

SUMMARYAgricultural research and development (R&D) would benefit from reliable yet cheap technology uptake indicators to guide decision making. The paper explores the use of village surveys to monitor technology use and illustrates this through two empirical case studies into tillage dynamics in the Trans-Gangetic Plains in northwest India. The first case study is a revisit of 50 communities surveyed earlier in Haryana State. The second case study is a new and wider representative sample of 120 villages across Haryana and Punjab States. The case studies illustrate that after an initial rapid spread of tractor-drawn zero tillage drills for wheat seeding in these intensive systems, the zero + reduced tillage area seems to have stabilized there at between a fifth and a quarter of the wheat area. Conventional tillage for wheat continues to decline, with an increased use of rotavators making up the difference – but its intensive shallow tillage goes against the conservation agriculture tenets. The paper illustrates the potential of village surveys to provide timely and cost-effective feedback to agricultural R&D.

Mineral/microfibrillated cellulose composite materials: High performance products, applications, and product forms

TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 507-515 ◽  
Author(s):  
David Skuse ◽  
Mark Windebank ◽  
Tafadzwa Motsi ◽  
Guillaume Tellier
Keyword(s):  
Composite Materials ◽  
High Performance ◽  
Aqueous Suspension ◽  
Production Capacity ◽  
Cost Savings ◽  
Cost Effective ◽  
New Materials ◽  
Wet Strength ◽  
Product Forms ◽  
Cellulose Composite

When pulp and minerals are co-processed in aqueous suspension, the mineral acts as a grinding aid, facilitating the cost-effective production of fibrils. Furthermore, this processing allows the utilization of robust industrial milling equipment. There are 40000 dry metric tons of mineral/microfbrillated (MFC) cellulose composite production capacity in operation across three continents. These mineral/MFC products have been cleared by the FDA for use as a dry and wet strength agent in coated and uncoated food contact paper and paperboard applications. We have previously reported that use of these mineral/MFC composite materials in fiber-based applications allows generally improved wet and dry mechanical properties with concomitant opportunities for cost savings, property improvements, or grade developments and that the materials can be prepared using a range of fibers and minerals. Here, we: (1) report the development of new products that offer improved performance, (2) compare the performance of these new materials with that of a range of other nanocellulosic material types, (3) illustrate the performance of these new materials in reinforcement (paper and board) and viscosification applications, and (4) discuss product form requirements for different applications.

Parallel Computing for Tire Simulations

2011 ◽  
Vol 39 (3) ◽  
pp. 193-209 ◽  
Author(s):  
H. Surendranath ◽  
M. Dunbar
Keyword(s):  
High Performance ◽  
Effective Means ◽  
Cost Effective ◽  
Turnaround Time ◽  
Careful Consideration ◽  
Rolling Contact ◽  
Element Analysis ◽  
Parallel Solvers ◽  
Design Changes ◽  
Highly Nonlinear

Abstract Over the last few decades, finite element analysis has become an integral part of the overall tire design process. Engineers need to perform a number of different simulations to evaluate new designs and study the effect of proposed design changes. However, tires pose formidable simulation challenges due to the presence of highly nonlinear rubber compounds, embedded reinforcements, complex tread geometries, rolling contact, and large deformations. Accurate simulation requires careful consideration of these factors, resulting in the extensive turnaround time, often times prolonging the design cycle. Therefore, it is extremely critical to explore means to reduce the turnaround time while producing reliable results. Compute clusters have recently become a cost effective means to perform high performance computing (HPC). Distributed memory parallel solvers designed to take advantage of compute clusters have become increasingly popular. In this paper, we examine the use of HPC for various tire simulations and demonstrate how it can significantly reduce simulation turnaround time. Abaqus/Standard is used for routine tire simulations like footprint and steady state rolling. Abaqus/Explicit is used for transient rolling and hydroplaning simulations. The run times and scaling data corresponding to models of various sizes and complexity are presented.

Interpreting Laser-Based Fault Localization Results: Case Studies

2019 ◽  
Author(s):  
Sukho Lee ◽  
John van den Biggelaar ◽  
Marc van Veenhuizen
Keyword(s):  
Case Studies ◽  
Circuit Design ◽  
High Sensitivity ◽  
Failure Behavior ◽  
Process Technology ◽  
Resistance Change ◽  
Voltage Imaging ◽  
Root Cause ◽  
First Case ◽  
Proper Interpretation

Abstract Laser-based dynamic analysis has become a very important tool for analyzing advanced process technology and complex circuit design. Thus, many good reference papers discuss high resolution, high sensitivity, and useful applications. However, proper interpretation of the measurement is important as well to understand the failure behavior and find the root cause. This paper demonstrates this importance by describing two insightful case studies with unique observations from laser voltage imaging/laser voltage probing (LVP), optical beam induced resistance change, and soft defect localization (SDL) analysis, which required an in-depth interpretation of the failure analysis (FA) results. The first case is a sawtooth LVP signal induced by a metal short. The second case, a mismatched result between an LVP and SDL analysis, is a good case of unusual LVP data induced by a very sensitive response to laser light. The two cases provide a good reference on how to properly explain FA results.

A Silicon Debugging Methodology on Customer Prototype for Wafer Foundries

2012 ◽  
Author(s):  
Mai Zhihong ◽  
Ng Tsu Hau ◽  
Dawood M. Khalid ◽  
Tan Pik Kee ◽  
Jeffrey Lam
Keyword(s):  
Case Studies ◽  
Semiconductor Industry ◽  
Full Information ◽  
Limited Information ◽  
Ip Protection ◽  
First Case ◽  
Silicon Debugging ◽  
Failure Location ◽  
Device Chip ◽  
Latch Up

Abstract IP protection is of major importance for a semiconductor company and only limited information is made available for device debugging for the product outsourced to a foundry. In order to position ourselves better in the ever competitive semiconductor industry, with the consideration of IP protection, we have to provide the customers with the Si debugging capability and device/chip verification services in foundry. This paper explores the Si debugging methodology and technique in a foundry. Two case studies are presented and discussed. The first case illustrates the isolation of the failure location by InGaAs microscopy, upon which the failure was identified to be caused by a latch-up issue. In the second case, due to confidentiality considerations from the customer, full information could not be provided to the foundry for silicon debugging. The paper illustrates the ability to effectively debug a failure despite being constrained by limited information from the customer.

THE USE OF CASE STUDY METHOD IN TEACHING THE TERMINOLOGY IN THE FIELD OF AGRICULTURAL MACHINERY

2019 ◽  
pp. 123-130
Keyword(s):  
Case Studies ◽  
High Performance ◽  
Mechanical Engineering ◽  
The United States ◽  
Machine Building ◽  
Soil Tillage ◽  
Case Study Method ◽  
Agricultural Machine ◽  
Manufacturing Machine

The scientific research works concerning the field of mechanical engineering such as, manufacturing machine slate, soil tillage, sowing and harvesting based on the requirements for the implementation of agrotechnical measures for the cultivation of plants in its transportation, through the development of mastering new types of high-performance and energy-saving machines in manufacturing machine slate, creation of multifunctional machines, allowing simultaneous soil cultivation, by means of several planting operations, integration of agricultural machine designs are taken into account in manufacturing of the local universal tractor designed basing on high ergonomic indicators. For this reason, this article explores the use of case studies in teaching agricultural terminology by means analyzing the researches in machine building. Case study method was firstly used in 1870 in Harvard University of Law School in the United States. Also in the article, we give the examples of agricultural machine-building terms, teaching terminology and case methods, case study process and case studies method itself. The research works in the field of mechanical engineering and the use of case studies in teaching terminology have also been analyzed. In addition, the requirements for the development of case study tasks are given in their practical didactic nature. We also give case study models that allow us analyzing and evaluating students' activities.

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