A least invasive method to estimate the residual strain capacity of steel reinforcement in earthquake-damaged buildings.

Capacity design and hierarchy of strength philosophies at the base of modern seismic codes allow inelastic response in case of severe earthquakes and thus, in most traditional systems, damage develops at well-defined locations of reinforced concrete (RC) structures, known as plastic hinges. The 2010 and 2011 Christchurch earthquakes have demonstrated that this philosophy worked as expected. Plastic hinges formed in beams, in coupling beams and at the base of columns and walls. Structures were damaged permanently, but did not collapse. The 2010 and 2011 Christchurch earthquakes also highlighted a critical issue: the reparability of damaged buildings. No methodologies or techniques were available to estimate the level of subsequent earthquakes that RC buildings could still sustain before collapse. No repair techniques capable of restoring the initial condition of buildings were known. Finally, the cost-effectiveness of an eventual repair intervention, when compared with a new building, was unknown. These aspects, added to nuances of New Zealand building owners’ insurance coverage, encouraged the demolition of many buildings. Moreover, there was a perceived strong demand from government and industry to develop techniques for assessing damage to steel reinforcement bars embedded in cracked structural concrete elements. The most common questions were: “Have the steel bars been damaged in correspondence to the concrete cracks?”, “How much plastic deformation have the steel bars undergone?”, and “What is the residual strain capacity of the damaged bars?” Minimally invasive techniques capable of quantifying the level and extent of plastic deformation and residual strain capacity are not yet available. Although some studies had been recently conducted, a validated method is yet to be widely accepted. In this thesis, a least-invasive method for the damage-assessment of steel reinforcement is developed. Based on the information obtained from hardness testing and a single tensile test, it is possible to estimate the mechanical properties of earthquake-damaged rebars. The reduction in the low-cycle fatigue life due to strain ageing is also quantified. The proposed damage assessment methodology is based on empirical relationships between hardness and strain and residual strain capacity. If damage is suspected from in situ measurements, visual inspection or computer analysis, a bar may be removed and more accurate hardness measurements can be obtained using the lab-based Vickers hardness methodology. The Vickers hardness profile of damaged bars is then compared with calibration curves (Vickers hardness versus strain and residual strain capacity) previously developed for similar steel reinforcement bars extracted from undamaged locations. Experimental tests demonstrated that the time- and temperature-dependent strain-ageing phenomenon causes changes in the mechanical properties of plastically deformed steels. In particular, yield strength and hardness increases, whereas ductility decreases. The changes in mechanical properties are quantified and their implications on the hardness method are highlighted. Low-cycle fatigue (LCF) failures of steel reinforcing bars have been observed in laboratory testing and post-earthquake damage inspections. Often, failure might not occur during a first seismic event. However, damage is accumulated and the remaining fatigue life is reduced. Failure might therefore occur in a subsequent seismic event. Although numerous studies exist on the LCF behaviour of steel rebars, no studies had been conducted on the strain-ageing effects on the remaining fatigue life. In this thesis, the reduction in fatigue life due to this phenomenon is determined through a number of experimental tests

THE EFFECTS OF FOOD AESTHETICS ON CONSUMERS. VISUAL STIMULI AND FOOD MARKETING

In this study we analyze how the visual impact influences consumers, in particular considering the way a food is presented, exploring in this way how food marketing is also a question of food appearance. Do we eat firstly with our eyes? And if yes, which are the consequences of this process on food marketing strategies? Literature highlights that the way food is presented produces effects from a celebral and a physiological point of view, but also how it affects taste. In the first part of this research literature has been explored, paying attention in particular on hunger as a process which begins from eyes and, secondly,on how neatness makes food more desiderable. The second part of the study shows our experiment on consumers. Specifically 71 subjects were involeved, divided into four groups, that had to observe and evaluate some plates of fruit and bresaola, once arranged neatly, once disorderly. Data have been gathered and analyzed, in particular highlighting consumers’ expectation about the tastiness of the food and how much they would have spent to eat that food. Finally we discuss about the findings, in particular underlining how neatness counts in the presentation. From the point of view of managerial implications, these findings may be useful to understand the role of appearance to implement a winning food marketing strategy

THE EFFECTS OF FOOD AESTHETICS ON CONSUMERS. VISUAL STIMULI AND FOOD MARKETING

In this study we analyze how the visual impact influences consumers, in particular considering the way a food is presented, exploring in this way how food marketing is also a question of food appearance. Do we eat firstly with our eyes? And if yes, which are the consequences of this process on food marketing strategies? Literature highlights that the way food is presented produces effects from a celebral and a physiological point of view, but also how it affects taste. In the first part of this research literature has been explored, paying attention in particular on hunger as a process which begins from eyes and, secondly,on how neatness makes food more desiderable. The second part of the study shows our experiment on consumers. Specifically 71 subjects were involeved, divided into four groups, that had to observe and evaluate some plates of fruit and bresaola, once arranged neatly, once disorderly. Data have been gathered and analyzed, in particular highlighting consumers’ expectation about the tastiness of the food and how much they would have spent to eat that food. Finally we discuss about the findings, in particular underlining how neatness counts in the presentation. From the point of view of managerial implications, these findings may be useful to understand the role of appearance to implement a winning food marketing strategy

monotonic and low cycle fatigue properties of earthquake damaged new zealand steel reinforcing bars the experience after the christchurch 2010 2011 earthquakes

Abstract The 2010 and 2011 Christchurch seismic events have highlighted the limitations of the current knowledge in assessing the residual capacity of earthquake-damaged reinforced concrete (RC) buildings. An important challenge during the assessment phase was determining the residual ductility and the remaining low-cycle fatigue life of damaged rebars. Low-cycle fatigue is a possible failure mechanism of steel reinforcing bars when subjected to large-amplitude cyclic loads, such as due to earthquakes. While a single seismic event may not cause rebar failure, the low-cycle fatigue life will be reduced due to plastic strain. Also, New Zealand (NZ)-manufactured Grade 300E is prone to strain ageing. This phenomenon causes a change in mechanical properties, such as increase in yield and ultimate tensile strength, return of a discontinuous yield point, reduction in ductility and rise in the ductile/brittle transition temperature, and must be considered in damage assessment. This paper discusses the effects of strain ageing on the monotonic and cyclic steel mechanical properties. Low-cycle fatigue tests were conducted on Grade 300E steel rebars. Reinforcing bar samples were subjected to constant and fully-reversed strain amplitude cycles. Strain amplitudes ranged from 0.5% to 3%. The strain-fatigue life curve for the un-aged steel was determined. The strain ageing effects on the fatigue life of Grade 300E were then investigated. Specimens were cyclically tested up to the 33% and 66% fatigue life previously determined and "artificially" aged at 100°C. Finally, they were cyclically tested until failure. The experimental data were analyzed and low-cycle fatigue models were calibrated using the Coffin-Manson empirical relationship. Fatigue lives of the un-aged and aged samples were then compared. Preliminary observations suggested that strain-ageing triggers a premature crack initiation which propagates until failure

On the Effectiveness of Using Virtual Reality to View BIM Metadata in Architectural Design Reviews for Healthcare

This article reports on a study that assessed whether Virtual Reality (VR) can be used to display Building Information Modelling (BIM) metadata alongside spatial data in a virtual environment, and by doing so determine if it increases the effectiveness of the design review by improving participants’ understanding of the design. Previous research has illustrated the potential for VR to enhance design reviews, especially the ability to convey spatial information, but there has been limited research into how VR can convey additional BIM metadata. A user study with 17 healthcare professionals assessed participants’ performances and preferences for completing design reviews in VR or using a traditional design review system of PDF drawings and a 3D model. The VR condition had a higher task completion rate, a higher SUS score and generally faster completion times. VR increases the effectiveness of a design review conducted by healthcare professionals

Immersive multi-performance parametric framework to enhance low-damage timber buildings design

In order to face the increasing challenges resulting from climate change and catastrophic events, the built environment has to deal with multi-performance requirements. The well-recognised dependency between seismic performance and environmental footprint calls for advanced technological solutions together with integrated (multi-)decision-making approaches, able to handle multiple and sometimes conflicting domains in building design. Combining sustainability with high seismic performance, the use of the timber low-damage post-tensioned structural system, also known as Pres-Lam, represents a viable strategy to design more resilient buildings. The components modularity enables also the proper adaptive capacity to meet changes in user demands over time. Nevertheless, to address the multiple potentials of this technology and to guide decision-makers towards the optimal solution, an integrated building design methodology is needed. Such an approach inherently leads to Multi-Objective Optimization (MOO) problems due to the conflictual nature of the goals involved. This paper proposes a parametric framework for the multi-performance optimization and evaluation of adaptive Pres-Lam buildings, through a comprehensive model within the Rhino-Grasshopper platform. The MOO is carried out through the evolutionary algorithm inside the Octopus component for Grasshopper. The aim is to reduce embodied and operational carbon emissions, while ensuring the proper seismic capacity of the post-tensioned timber frames and the maximum flexibility of the internal space. The effective seismic performance of the selected Pareto optimal solutions is then assessed through a probabilistic approach. Besides the use of a multi-comprehensive and easy-to-handle model, visualization plays an important role in building design. In this respect, architectural modelling radically evolved over the last decades towards increasing use of Virtual Reality (VR) along the design process. Despite this, VR is mostly used for the end visualization of 3-dimensional software-based models. This study aims to address the challenge of bringing the parametric modelling capability of Grasshopper within the immersive environment of VR. The designer has thereby the chance to directly modify the calculations input from within and to have real-time feedback of the model generated by the multi-performance integrated framework for low-damage timber buildings

Luigi Pirandello, Saggi 1: Suoni e sviluppi fonetici della parlata di Girgenti, a cura di Michele Loporcaro e Luca Pesini; Arte e scienza, a cura di Giuseppe Langella e Davide Savio; L'umorismo, a cura di Giuseppe Langella e Davide Savio

La tesi di laurea di Pirandello in linguistica romanza (scritta in tedesco e discussa a Bonn nel 1891) è qui riproposta in una nuova traduzione che ne pone in risalto il metodo scientifico, sorretto dalla competenza nativa dell'autore. Nella seconda sezione del volume, Arte e scienza e L'umorismo, nella princeps del 1908, vengono per la prima volta messi in dialogo, come le due facce di un'unica riflessione in materia di estetica e di poetica

Performance of road bridges during the 14 November 2016 Kaikoura earthquake

he transport infrastructure was majorly affected by the 14lh November 2016 Kaikōura Earthquake. Severe vertical and horizontal peak ground accelerations generated high inertial forces, land-slides, and liquefaction. Most of the bridges in the Hurunui, Malborough and Kaikōura districts were critical nodes to the railway and road networks. In total, 904 road bridges across those districts were affected. Two reached the life safety limit state, suffering severe damage, however, most of the affected bridges experienced only minor to moderate damage. This paper describes the structural performance of the most severely damaged bridges based on observations made from site inspections. In addition to this, several performance issues have arisen from this event and are posed in this paper, hopefully to be addressed in the near future