An overview of historical and contemporary concrete shells, their construction and factors in their general disappearance

Only through understanding why concrete shells’ loss in popularity over the course of modern history can designers be equipped with the skills to create and apply this type of construction. Through modifications to design processes, construction stages, material understanding and relevant formwork improvements will architects and designers be able to meet the demands of the 21st century and beyond. To understand why concrete shells are no longer commonly built is to understand its construction process. An amorphous material, the fundamental relationship between formwork and the resultant concrete shell needs to be raised, appreciated, understood and analyzed for a holistic understanding of concrete shells. Through understanding this, issues and factors affecting concrete shells can be tackled and designed out in reviving this type of structures because they can be efficient in structural performance, economical in cost and provide high aesthetic value. This paper discusses concrete shells as an architectural solution by asking the question to what constituted their popularity and factors that led to their demise in the modern age of technological advancement, construction process and environmental concerns. This paper presents a cultural perspective and an overview of seminal, historical and contemporary concrete shells so as to bring about a renaissance of such structures in our built environment once again because of all the benefits it can offer.</p

Prototipos cerámicos – diseño, computación y fabricación digital

Research in ceramic material systems at Harvard University has introduced a range of novel applications which combine digital manufacturing technologies and robotics with imaginative design and engineering methods. Prototypes showcase the new performative qualities of ceramics and the integration of this material in today’s construction culture. Work ranges from daylight control systems to structural applications and a robotic tile placement system. Emphasis is on integrating novel technologies with tried and true manufacturing methods. The paper describes two distinct studies – one on 3D print-ing of ceramics, the other on structural use of large format thin tiles.Las investigaciones de la Universidad de Harvard en sistemas de material cerámico han introducido una gama de aplicaciones novedosas que combinan tecnologías de fabricación digital y robótica con diseños imaginativos y métodos de ingeniería. Los prototipos muestran las nuevas prestaciones de la cerámica y la integración de este material en la cultura de la construcción actual. Los trabajos van desde sistemas de control de luz natural a aplicaciones estructurales y un sistema de colocación de tejas robóticas. Se hace hincapié en la integración de nuevas tecnologías con métodos de fabricación probados y reales. El documento describe dos estudios distintos: uno sobre la impresión 3D de cerámica y el otro sobre el uso estructural de baldosas delgadas de gran formato

Social norms and groups structure safe operating spaces in renewable resource use in a social-ecological multi-layer network model

Social norms are a key socio-cultural driver of human behaviour and have been identified as a central process in potential social tipping dynamics. They play a central role in governance and thus represent a possible intervention point for collective action problems in the Anthropocene, such as natural resource management. A detailed modelling framework for social norm change is needed to capture the dynamics of human societies and their feedback interactions with the natural environment. To date, resource use models often incorporate social norms in an oversimplified manner, as a robust and detailed coupled social-ecological model, scaling from the local to the global World-Earth scale, is lacking. Here we present a multi-level network framework with a complex contagion process for modelling the dynamics of descriptive and injunctive social norms. The framework is complemented by social groups and their attitudes, which can significantly influence the adoption of social norms. We integrate the modelling concept of norms together with an additional individual social learning component into a model of coupled social-ecological dynamics with a closed feedback loop, implemented in the copan:CORE framework for World–Earth modelling. We find that norms generally bifurcate the behaviour space into two extreme states: one sustainable and one unsustainable. Reaching a sustainable (i.e. safe) state becomes more likely with low thresholds of conforming to sustainable norms, as well as lower consideration rates of own resource harvesting success. Modelling both descriptive and injunctive norms independently and dynamically introduces additional intermediate states, e.g. when there are countervailing norms. The shape of the bifurcation depends on the number of groups and members and thus on the social network topology. Where groups are very inert in changing their attitudes and thus consistently convey the same norm, multiple stable basins for sustainability levels are found. Groups influence the dynamics by facilitating or inhibiting the contagion of sustainable behaviour by communicating their norms. The success of a generic social norm intervention is also found to be highly dependent on the group topology. Our findings suggest that explicitly modelling social norm processes together with social groups enriches the dynamics of social-ecological models and determines safe operating spaces. Consequently, both should be taken into account when representing human behaviour in coupled World–Earth models.1 Introduction 1.1 Social norms & social groups 1.2 Coupled natural resource management 1.3 Social norm modelling framework 1.4 The Nexploit model 2 Model description 2.1 Biophysical component: resource growth 2.2 Social-metabolic component: harvesting 2.3 Socio-cultural component: social norm framework 2.3.1 Agent layer 2.3.2 Descriptive norm 2.3.3 Group layer 2.3.4 Injunctive norm 2.3.5 Social update 3 Results 3.1 Groups & group memberships 3.1.1 Analysis of micro dynamics 3.1.2 Fixed group attitude 3.2 Thresholds 3.3 Timescales 3.4 Group attitude intervention 3.5 Discussion 4 Conclusions Limitations & outloo

Social norms and groups structure safe operating spaces in renewable resource use in a social–ecological multi-layer network model

Social norms are a key socio-cultural driver of human behaviour and have been identified as a central process in potential social tipping dynamics. They play a central role in governance and thus represent a possible intervention point for collective action problems in the Anthropocene, such as natural resource management. A detailed modelling framework for social norm change is needed to capture the dynamics of human societies and their feedback interactions with the natural environment. To date, resource use models often incorporate social norms in an oversimplified manner, as a robust and detailed coupled social–ecological model, scaling from the local to the global world–Earth scale, is lacking. Here we present a multi-level network framework with a complex contagion process for modelling the dynamics of descriptive and injunctive social norms. The framework is complemented by social groups and their attitudes, which can significantly influence the adoption of social norms. We integrate the modelling concept of norms together with an additional individual learning component into a model of coupled social–ecological dynamics with a closed feedback loop, implemented in the copan:CORE framework for world–Earth modelling. We find that norms generally bifurcate the behaviour space into two extreme states: one sustainable and one unsustainable. Reaching a sustainable (i.e. safe) state becomes more likely with low thresholds of conforming to sustainable norms, as well as lower consideration rates of own resource harvesting success. Modelling both descriptive and injunctive norms independently and dynamically introduces additional intermediate states, e.g. when there are countervailing norms. The shape of the bifurcation depends on the number of groups and members and thus on the social network topology. Where groups are very inert in changing their attitudes and thus consistently convey the same norm, multiple stable basins for sustainability levels are found. Groups influence the dynamics by facilitating or inhibiting the contagion of sustainable behaviour by communicating their norms. The success of a generic social norm intervention is also found to be highly dependent on the group topology. Our findings suggest that explicitly modelling social norm processes together with social groups enriches the dynamics of social–ecological models and determines safe operating spaces. Consequently, both should be taken into account when representing human behaviour in coupled world–Earth models.</p

From farm to planet: the InSEEDS World-Earth Model for simulating transitions to regenerative agriculture

Industrialised agriculture and its externalisation of environmental costs have contributed to accelerating ecological degradation and the transgression of planetary boundaries. Vice versa, agriculture is increasingly affected by ecological pressures such as climate change. While sustainable approaches like Regenerative Agriculture offer promising alternatives, most studies focus on the biophysical impacts of individual practices and overlook the complex dynamics underlying their large-scale adoption. In particular, the roles of social-ecological feedbacks, tipping dynamics, and transformative change remain underexplored. To address this gap, we introduce the InSEEDS integrated World-Earth model – a novel co-evolutionary approach to simulating agricultural transitions that couples a process-based vegetation model (LPJmL) with an agent-based model of farmer decision-making. InSEEDS integrates socio-cultural, social-ecological, and biophysical dynamics and can be applied from local to global scales. Distinguishing between a traditionalist and pioneer farmer types, we analyse the adoption dynamics of conservation tillage as a key practice of Regenerative Agriculture. We find that social networks, ecological heterogeneity, and decision-making inertia play a critical role in determining transition dynamics. Adoption of conservation tillage yields overall positive effects on soil carbon and crop yield, though outcomes are strongly context-dependent. InSEEDS provides a foundational tool that opens up avenues for understanding complex human-environment interactions in land-use transformations and advancing the next generation of World-Earth models.1 Introduction 2 InSEEDS model description 2.1 Environmental taxon: conservation tillage as a RA practice 2.2 Socio-cultural and metabolic taxa: social-ecological dynamics of management changes 3 Simulation experiments with the InSEEDS model 3.1 Model parametrisation 3.2 Simulation experiments and simulation protocol overview 3.3 Sensitivity analysis 4 Results 4.1 Parameter sensitivity 4.2 Coupled, co-evolutionary model dynamics across scales 4.2.1 National scale 4.2.2 Local / cell scale 5 Discussion 6 Limitations and Future Directions 7 Conclusion

Gridshell as Formwork: Proof of Concept for a New Technique for Constructing Thin Concrete Shells Supported by Gridshell as Formwork

This paper documents an empirical experiment conducted in August 2014 as proof of concept for a new method of constructing concrete shells. An idea initially presented by the first author in 2012, it uses redeployable gridshells onto which fabric is midstressed and concrete applied. Primarily, this system addresses key issues that led to their decline in use: construction methods/formwork systems were not reusable, nor were they easily customizable to create different shapes. Employing 27 man-hours over seven days, two concrete shells were achieved using the same reusable and reconfigurable formwork. Lightweight (0.6 kg) PVC gridshell formwork supported 106.92 kg of concrete to create a concrete shell that covered 1.11 m2 (floor area). The construction verifies a low-cost (£6.06/m2) efficiency and material utilization in the construction of very strong wide-spanning thin concrete structures. Detailed analysis of formwork behavior during construction and detailed measurements of resultant shell results prove this new method of deployable gridshells as a reusable and reconfigurable formwork to construct very strong concrete shells very quickly. Whilst the emphasis of the research focused on the construction process, the vaults were tested and sustained a failure load of 4.2 kN (4.32 times their deadweight), applied as a point load at the crown

Synthesis of phosphonate-functionalized polystyrene and poly(methyl methacrylate) particles and their kinetic behavior in miniemulsion polymerization

Phosphonate-functionalized polymer nanoparticles were synthesized by free-radical copolymerization of vinylphosphonic acid (VPA) with styrene or methyl methacrylate (MMA) using the miniemulsion technique. The influence of different parameters such as monomer and surfactant type, amount of vinylphosphonic acid on the average particle size, and size distribution was studied using dynamic light scattering and transmission electron microscopy. Depending on the amount and type of the surfactant used (ionic or non-ionic), phosphonate-functionalized particles in a size range from 102 to 312 nm can be obtained. The density of the phosphonate groups on the particle surface was higher in the case of using MMA as a basis monomer than polystyrene. The kinetic behavior of VPA copolymerization with styrene or MMA using a hydrophobic initiator was investigated by reaction calorimetry. Different kinetic curves were observed for miniemulsion (co)polymerization of styrene- and MMA-based nanoparticles indicating different nucleation mechanisms