Analytical and Experimental Evaluation of Precast Sandwich Wall Panels Subjected to Blast, Breach, and Ballistic Demands

Due to heightened security concerns federal as well as many public facilities require some level of blast design, whether it be intentional or accidental. In addition, with the increasing cost in utilities and continuous rise in global warming, a movement has begun to streamline the construction process and limit the environmental footprint of every building. In response, the federal government now requires that all government buildings not only be designed for blast loads, but also sustainability.Insulated wall panels are capable of meeting both the blast and sustainable requirements due to the inherit strength of a reinforced concrete slab and the thermal resistance provided from the insulating layer; however, limited experimental testing is available to prove that insulated wall panels are an ideal system for both blast and sustainability. The objective of this research is to develop the tools to design a blast and ballistic resistant insulated wall panel system. As part of this research, experimental tests were conducted on insulated panels to validate models developed to predict panel behavior observed. Using the results of the research an approach was developed to create a 1) Thermally efficient, 2) Blast Resistant, 3) Spall/Breach Resistant and 4) Ballistic Resistant panel.Insulated wall panels are inherently thermally resistive due to the insulating foam located between the two layers of concrete. Parametric studies were performed via analytical calculations to determine the efficiency of the wall system. The calculations indicated that the insulating layer is fundamental to the resistance of the panel; an 8in. solid concrete panel had a thermal resistance of less than 10% of a panel 2in. of insulation sandwiched between two 3in. concrete wythes. Additionally, the parametric study indicated that the shear connectors located between the interior and exterior wythes can have a significant effect on the overall panel thermal resistance due to the thermal bridging phenomenon. Three panels were modeled with identical layout and wythe connectors with identical dimensions but different material: concrete, steel, and low-conductive material. The panel with concrete and steel wythe connectors saw a reduction in thermal resistance compared to the low-conductive material of nearly 78% and 62%respectively. Thus, to decrease the panel resistance while maintaining strength, a strong thermally resistive material must be used as a shear connector.To improve the response to far-field detonations, experimental tests were performed on small solid panels as well as larger insulated panels. Locally unbonding the small solid panels allowed the panel to reach support rotations past the 10° specified by the United States Army Corps of Engineers as the highest threat level while the bonded panels reached less than 5° before softening. Additionally, testing of insulated wall panels revealed that the panel behavior is highly dependent on the shear tie constitutive property and location along the span. A numerical model was created to predict the behavior of an insulated and as a result, a new shear tie was developed to improve the flexural response of the panel while at the same time, decreasing the production cost.To assess the response of insulated wall panels to close-in detonations, experimental tests and numerical models were conducted. The tests revealed that the insulation results in a detriment to panel performance as a panel with 2in. of insulation sandwiched between two 3in. thick concrete wythes breaches the exterior wythe while a 6in. thick solid concrete panel does not breach under the same demand. As the insulating layer thickness is increased, the panel does not breach due to the increased standoff created by the additional thickness. Additionally, the empirical formulas developed by the Unified Facilities Criteria for solid panels were shown to be inaccurate when used for insulated wall panels, while numerical simulations were able to bound the response of an insulated wall panel.To investigate the performance of insulated wall panels to ballistic and fragment demands, a probabilistic method was developed. The method results in the creation of fragility curves allowing a designer to assess the probability of perforation and residual velocity for a given threat at any wall thickness. Additionally, the likelihood of injury occurring to personnel behind the wall panel was assessed by using organ threshold tolerances provided in literature. Using the method developed, engineers can design the thickness of an insulated wall panel to achieve an acceptable probability of occurrence for injury.Finally, all of the material learned through the first four stages were combined to create a comprehensivedesign example. An 8in. thick panel with 2in. of insulation was designed using the newly designed shear tie as well as a ductile shear tie with the same strength, and then subjected to the demands reviewed throughout the research project. The tie system allowed the wall to reach a support rotation of 10° while behaving in a moderate to heavy damage level when subjected to the far-field detonation demand. From the conclusions of the close-in detonation study, the panel is known to breach under the load prescribed. Ballistic fragility curves were developed showing that the panel stops a low threat ballistic with 100% certainty, but under a high ballistic threat the projectile has an 86.5% chance of perforating the wall system. For the fragmenting munition considered in the study, the wall system has a 15.4% chance of causing injury to personnel behind the wall. Finally, by using the new shear tie system developed, the wall system results in a reduction of less than 3% in the total R-value when compared to an insulated panel without thermal bridges due to the low thermal conductivity of the shear tie material

Technology and Management for Sustainable Buildings and Infrastructures

A total of 30 articles have been published in this special issue, and it consists of 27 research papers, 2 technical notes, and 1 review paper. A total of 104 authors from 9 countries including Korea, Spain, Taiwan, USA, Finland, China, Slovenia, the Netherlands, and Germany participated in writing and submitting very excellent papers that were finally published after the review process had been conducted according to very strict standards. Among the published papers, 13 papers directly addressed words such as sustainable, life cycle assessment (LCA) and CO2, and 17 papers indirectly dealt with energy and CO2 reduction effects. Among the published papers, there are 6 papers dealing with construction technology, but a majority, 24 papers deal with management techniques. The authors of the published papers used various analysis techniques to obtain the suggested solutions for each topic. Listed by key techniques, various techniques such as Analytic Hierarchy Process (AHP), the Taguchi method, machine learning including Artificial Neural Networks (ANNs), Life Cycle Assessment (LCA), regression analysis, Strength–Weakness–Opportunity–Threat (SWOT), system dynamics, simulation and modeling, Building Information Model (BIM) with schedule, and graph and data analysis after experiments and observations are identified

A Roadmap for a SUstainable integrated REtrofit of CONcrete buildings: Proceedings of the SAFESUST2 - SURECON Workshop

The Joint Research Centre is contributing to the formulation, implementation and promotion of European policies on strengthening the internal market for buildings and building products. This includes the development and adoption of innovative materials, construction technologies and design methods for safe, resilient and resource-efficient buildings across their lifecycle. This activity is developed within the Project SAFE&CLEAN-CONSTRUCT (Safe and Cleaner Technologies for Construction and Buildings). In particular, the Workpackage SAFESUST (Impact of Sustainability and Energy Efficiency Requirements on Building Design and Retrofit) is aiming at developing a holistic design method, for assessing the global performance of buildings in terms of safety, energy efficiency and environmental impact. This method, named Sustainable Structural Design (SSD) method, or simply SAFESUST method, considers both environmental and structural parameters in a life cycle perspective, and the results are expressed in purely economic terms, so that it can be potentially used by all categories of stakeholders. In developing this approach, the necessary Roadmap is being drafted with the contribution of experts from different disciplines, and this is the aim of the SAFESUST workshop series. A first SAFESUST workshop was held in Ispra in 2015 and was devoted to the definition of a “Roadmap for the improvement of earthquake resistance and eco-efficiency of existing buildings and cities”. That Workshop had the participation of experts from different areas of expertise, namely Architecture and City Planning, Energy, Materials and Structures, as well as Financial. The Workshop was organized in technical sessions, with keynote lectures, technical presentations and discussions based on the syntheses produced by the rapporteurs, and was said to be a success. A similar scheme is being proposed for this SAFESUST 2 - SURECON Workshop “A Roadmap for the sustainable integrated retrofit of concrete buildings”. In this workshop efforts will be paid to extend the roadmap for integrated retrofit of existing buildings to include actions other than earthquakes. The collaboration with the University of Leeds, with which the Workshop is being co-organized, has been instrumental to the definition of important case studies, such as the multi-storey concrete panel buildings, which proved to have both insufficient thermal performances and insufficient robustness, and badly need a holistic approach for their renovation.JRC.E.4-Safety and Security of Building

Proceedings of the 1st International Workshop on Resilience

Built environment constitutes the fundamental layer for many services and functions of our society. Many physical infrastructures are vulnerable to natural hazards (e.g. earthquakes, floods, tornados) as well as man-made hazards, and the risk of catastrophic damage due to hazardous events continues to increase worldwide. Considerable progress has been made towards risk management and mitigation, however, in particular the earthquake engineering community still faces many new challenges. Focusing principally on seismic resilience, the objectives of the workshop have centred on (i) how we use resilience-based engineering to steward our built environment and make it safer, resilient and sustainable, and (ii) how to assess and develop strategies to improve community resilience against a major disruptive event. The workshop has comprised presentations and discussion sessions. The state of knowledge regarding disaster resilience has first been examined in the light of the lessons learnt from recent major earthquakes. Then the views and approaches were solicited with contributions from Japan, Asia, Europe, North and South America on the new directions for Resilience-Based Design (RBD) in an effort towards catalysing and elaborating a comprehensive, collective and integrated approach to resilience. Currently running research projects on resilience, funded by the EU, were also presented.JRC.E.4-Safety and Security of Building

Resilience of critical structures, infrastructure, and communities

In recent years, the concept of resilience has been introduced to the field of engineering as it relates to disaster mitigation and management. However, the built environment is only one element that supports community functionality. Maintaining community functionality during and after a disaster, defined as resilience, is influenced by multiple components. This report summarizes the research activities of the first two years of an ongoing collaboration between the Politecnico di Torino and the University of California, Berkeley, in the field of disaster resilience. Chapter 1 focuses on the economic dimension of disaster resilience with an application to the San Francisco Bay Area; Chapter 2 analyzes the option of using base-isolation systems to improve the resilience of hospitals and school buildings; Chapter 3 investigates the possibility to adopt discrete event simulation models and a meta-model to measure the resilience of the emergency department of a hospital; Chapter 4 applies the meta-model developed in Chapter 3 to the hospital network in the San Francisco Bay Area, showing the potential of the model for design purposes Chapter 5 uses a questionnaire combined with factorial analysis to evaluate the resilience of a hospital; Chapter 6 applies the concept of agent-based models to analyze the performance of socio-technical networks during an emergency. Two applications are shown: a museum and a train station; Chapter 7 defines restoration fragility functions as tools to measure uncertainties in the restoration process; and Chapter 8 focuses on modeling infrastructure interdependencies using temporal networks at different spatial scales

Life Cycle Assessment on Green Building Implementation

Greenhouse-gas emissions have become one of the most impacting environmental issues in today’s society. A rapidly increasing trend in global CO2emissions particularly since the early nineties (23.64% since 1990) has led to the generation of about 50,000 million tons of CO2–equivalent (eqv) worldwide in 2010. According to mainstream climate experts, the increasing concentration of greenhouse-gases is having a warming effect on the world climate. To slow down global warming, there is a global focus on reducing greenhouse-gas emissions. Life cycle assessment in green building implementation is the focus of this Special Issue

Science for Disaster Risk Reduction

This thematic report describes JRC's activities in support to disaster management. The JRC develops tools and methodologies to help in all phases of disaster management, from preparedness and risk assessment to recovery and reconstruction through to forecasting and early warning.JRC.A.6-Communicatio