Seismic design of reinforced concrete frames for minimum embodied CO2 emissions

Optimum structural design of reinforced concrete (RC) frames has been the focus of extensive research. Typically, previous studies set economic cost as the main design objective despite the fact that RC structures are major contributors of CO2 emissions. The limited number of studies examining optimum design of RC frames for minimum CO2 emissions do not address seismic design considerations. However, in many countries around the world, including most of the top-10 countries in CO2 emissions from cement production, RC structures must be designed against earthquake threat. To bridge this gap, the present study develops optimum seismic designs of RC frames for minimum cradle to gate embodied CO2 emissions and compares them with optimum designs based on construction cost. The aim is to identify efficient design practices that minimize the environmental impact of earthquake-resistant RC frames and examine the trade-offs between their cost and CO2 footprint. To serve this goal, an RC frame is optimally designed according to all ductility classes of Eurocode 8 and for various design peak ground accelerations (PGAs), concrete classes and materials embodied CO2 footprint scenarios. It is found that the minimum feasible CO2 emissions of RC frames strongly depend on the adopted ductility class in regions of high seismicity, where low ductility seismic design can generate up to 60% more CO2 emissions than designs for medium and high ductility. The differences reduce, however, as the level of seismicity decreases. Furthermore, CO2 emissions increase significantly with the design PGA. On the other hand, they are less sensitive to the applied concrete class. It is also concluded that, for medium to high values of the ratio of the unit environmental impact of reinforcing steel to the respective impact of concrete, the minimum CO2 seismic designs are very closely related to the minimum cost designs. However, for low values of the same ratio, the minimum cost design solutions can generate up to 13% more emissions than the minimum CO2 designs

Modularisation Strategies for Individualised Precast Construction—Conceptual Fundamentals and Research Directions

Modular precast construction is a methodological approach to reduce environmental impacts and increase productivity when building with concrete. Constructions are segmented into similar precast concrete elements, prefabricated with integrated quality control, and assembled just-in-sequence on site. Due to the automatised prefabrication, inaccuracies are minimised and the use of high-performance materials is enabled. As a result, the construction process is accelerated, and the modules can be designed to be lightweight and resource-efficient. This contribution presents the fundamentals of modular constructions made from precast concrete components. Then, to elaborate the requirements of a contemporary modular precast construction, the historic developments are described. Further, concepts and technical processes–comprehensible to non-expert readers–are introduced to formalise the discussion about the current state-of-the-art methods. Three case studies treating ongoing research are introduced and related to the conceptual fundamentals. The research is evaluated with regard to current barriers and future directions. In conclusion, modular precast construction is able to reduce emissions and increase productivity in the sector if researchers and firms coordinate the development of suitable technologies that bring value to critical stakeholders

Advancements in geospatial monitoring of structures

The need for advancements in geospatial monitoring of structures has evolved naturally as structures have become larger, more complex, and technology has continued to rapidly develop. Greater building heights generally lead to greater challenges for surveyors, limiting the practical use of traditional measurement methods. For this reason, a new complimentary method was developed and implemented to support elevation monitoring activities during construction of the Salesforce Tower in San Francisco, California. While some studies have explored the use of strain gauges to monitor strain development within individual members, the primary contribution of this work is that it presents a practical and proven to be implementable approach to estimating elevation changes throughout a multi-story reinforced concrete core wall tower during construction while utilizing strain measurements acquired at intermittent levels. Construction in urban landscapes has the potential to impact existing infrastructure. Identifying and mitigating any associated construction impacts is critical to public safety and construction progress. The development of Automated Motorized Total Stations (AMTS) has provided an effective means to monitor deformations in structures adjacent to construction activity. AMTS provides real time results so that movements may be immediately identified and addressed. However, the design, implementation, management, and analysis of these systems has frequently been problematic. Inadequate monitoring specifications have led to systems that fail to perform as intended even when project requirements were satisfied. A collection of monitoring specifications and AMTS projects have been reviewed to identify why certain problems have occurred and recommendations have been made to increase the probability of success on monitoring projects. A deformation monitoring approach that defines location specific threshold values based on a statistical analysis of baseline measurements is also presented in this dissertation. Identifying potential causes for monitoring specifications to fail to perform as intended and a deformation monitoring approach that defines location specific threshold values are secondary contributions of this dissertation

Challenges of Car Pack Design in Nigeria

Problems of parking space in urban towns and in all places of large congregation is becoming a common issue around the world. Over the years engineers and architects have come up with a lot of solutions finding a way to create more parking spaces within minimum size of land by the design and construction of multi-storey car parks. This is line with the trend in modern cities all over the world of developing high-rise buildings as to overcome the challenges of urban over population, for optimal use of scarce land resources, as status symbol, etc. Standing on the advances made so far and the frequent problematics verified on existing multi-storey car parks, this research presents the design of a multi-storey car park for the mitigation of traffic challenges in public areas using Canaan land, Ota Nigeria as a case study. Canaan land, the seat of Faith Tabernacle in Ota, Ogun State of Nigeria is used as a case study because of the amount of vehicles that compete for parking space on Sundays or on other days of events. The research consist of the creation of the architectural drawings of the multi-storey car park with AutoCAD drafting and the modelling, structural analysis and design using the software Orion R16. The structural analysis and design were challenging but good results were obtained, approach for more innovative multi-storey car park identifie

Challenges of Car Pack Design in Nigeria

Problems of parking space in urban towns and in all places of large congregation is becoming a common issue around the world. Over the years engineers and architects have come up with a lot of solutions finding a way to create more parking spaces within minimum size of land by the design and construction of multi-storey car parks. This is line with the trend in modern cities all over the world of developing high-rise buildings as to overcome the challenges of urban over population, for optimal use of scarce land resources, as status symbol, etc. Standing on the advances made so far and the frequent problematics verified on existing multi-storey car parks, this research presents the design of a multi-storey car park for the mitigation of traffic challenges in public areas using Canaan land, Ota Nigeria as a case study. Canaan land, the seat of Faith Tabernacle in Ota, Ogun State of Nigeria is used as a case study because of the amount of vehicles that compete for parking space on Sundays or on other days of events. The research consist of the creation of the architectural drawings of the multi-storey car park with AutoCAD drafting and the modelling, structural analysis and design using the software Orion R16. The structural analysis and design were challenging but good results were obtained, approach for more innovative multi-storey car park identified

Monitoring the axial displacement of a high-rise building under construction using embedded distributed fibre optic sensors

The floor-to-floor axial shortening of vertical load-bearing elements is an important factor in the design and construction of high-rise buildings. Contractors need to allow for the expected final compression of columns and walls due to superimposed load, concrete creep and shrinkage, particularly when installing finishes and partitions in lower floors, while the building has not yet been completed. An added complication arises from the differential shortening between elements of different stiffness. This axial shortening is predicted by designers using empirical models, in advance of construction. However, in practice, the shortening at every level cannot be measured continuously using traditional surveying measurement techniques during construction. Therefore, a monitoring system using distributed fibre optic sensors (DFOS) measuring strain and temperature, is being installed during the construction of Principal Tower, a 50-storey reinforced concrete building in London. DFOS sensors are being embedded inside two columns and two walls as the construction progresses. Using the strain and temperature data acquired from this system, the axial deformation relative to the ground level can be calculated along the whole height of the completed elements, at any time during the construction. Thus, the engineers and contractors are able to verify their predictions and adjust their assumptions if necessary. A selection of the data acquired during the construction of the first 17 levels of the building is presented. These data have shown that the amount of shortening experienced by a member is influenced by the member’s stiffness and size. The monitoring data have also revealed that thermal movement has a significant effect on the overall axial displacement of the building

A Qualitative Method for Assessing the Impact of ICT on the Architectural Design Process

During the last thirty years or so, we have witnessed tremendous developments in information and communication technology (ICT). Computer processing power doubles each 18 months, as Gordon Moore predicted during the mid-1960s. The computer and communications world has been revolutionised by the invention of the Internet. It has changed the way of exchanging, viewing, sharing, manipulating and storing the information. Other technologies such as smartphones, wearable computers, tablets, wireless communications and satellite communications have made the adoption of ICT easier and beneficial to all its users. ICT affects the productivity, performance and the competitive advantage of a business. It also impacts on the shape of the business process and its product. In architectural design, ICT is widely used throughout the design process and its final product. The aim of this research, therefore, is to explore the key implication of using ICT in architectural design and what new changes and forms have occurred on buildings as a result of ICT developments and use by architecture practitioners. To achieve this aim, a qualitative research approach was adopted using a narrative review of ICT usage in the design of buildings. The literature found was subjected to a thematic analysis of how ICT adoption affected the architectural design process. The findings of this research indicate that there is a continuous change in the design process and its final products (buildings) as the technology evolves. The framework proposed provides a foundation for gathering evidence from case studies of the impact of ICT adoption by architectural designers. The research proposes that future empirical work has to be conducted to test and refine the relevance, importance and applicability of each of the components of the framework, in order to detect the impact of ICT on the building design process and its final product

Üretim Mimarisi Üzerine Bir Araştırma: İmalathanelerden Makine Bölgelerine

Anthropocene is the present geological epoch in which human-built infrastructures dominate the resources of the world and highest levels of human intrusion to the ecosystems have been accumulated since the Industrial Revolution. Utilisation of the steam engine initiated change in energy sources and extraction of raw materials that altered the existent means of production and led to the hegemony of industrial activities. The spread and growth of industry prevailed onto the practice of architecture to construct rapidly developing bases of production, storage, and distribution. Therefrom, physical embodiments of these bases as an overall system enable to relate energy, labour, and technology as fundamental elements of industry with the discourse of architecture. Hence, this thesis studies three determined architectural typologies -mills, daylight factories, machine landscapes- for the evolution of production by a historical literature survey and comparative analysis of multiple cases with the compiled architectural documentation including photographs, drawings, and diagrams. Chronologically organised cases from different industrial periods reflect the altering nature of energy, labour, and technology regarding means of production, construction techniques, and materials. Acting as design parameters through the spatial transformation from mills to daylight factories, and now to machine landscapes, these relations indicate the interdependency between architecture and industry, and allow to formulate further spatial entities for production.Antroposen, insan yapımı altyapıların Dünya kaynaklarına hâkim olduğu ve Sanayi Devrimi'nden bu yana ekosistemlere en yüksek düzeyde insan müdahalesinin biriktiği mevcut jeolojik çağdır. Buhar makinesinin kullanımıyla başlayan enerji kaynaklarında ve hammaddelerin çıkartılmasındaki değişim, mevcut üretim araçlarının farklılaşmasına ve endüstriyel faaliyetlerin hegemonyasına yol açtı. Endüstrinin yayılımı ve büyümesi, hızla gelişen üretim, depolama ve dağıtım temellerini inşa etmek için endüstriyi mimarlığın uygulanma aşamasına yönlendirdi. Bu noktadan yola çıkarak, genel bir sistem halinde bu temellerin somutlaştırılmış düzenlemeleri, endüstrinin temel unsurları olan enerji, emek ve teknolojiyi mimarlık söylemiyle ilişkilendirmeyi mümkün kılar. Bu nedenle, bu tez, üretimin evrimi için belirlenmiş üç mimari tipolojiyi -imalathaneler, gün ışığı fabrikaları, makine bölgeleri- tarihsel bir literatür taraması ve birçok örneğin mimari belgesi olan fotoğrafları, çizimleri ve diyagramları aracılığıyla karşılaştırmalı analizi üstünden çalışır. Farklı endüstriyel dönemlerden seçilmiş ve kronolojik olarak organize edilmiş bu örnekler, enerji, emek ve üretim araçları, inşaat teknikleri ve malzemelerle ilgili olarak teknolojinin değişen doğasını yansıtır. Tasarım parametreleri olarak imalathanelerden gün ışığı fabrikalarına ve güncel olarak da makine bölgelerine doğru mekânsal dönüşümü sağlayan bu ilişkiler, mimari ve endüstri arasındaki karşılıklı bağlılığı gösterir ve üretim için daha fazla mekânsal varlıkları formüle etmeye izin verir.M.Arch. - Master of Architectur

A 5D Building Information Model (BIM) for Potential Cost-Benefit Housing: A Case of Kingdom of Saudi Arabia (KSA)

The Saudi construction industry is going through a process of acclimatizing to a shifting fiscal environment. Due to recent fluctuations in oil prices, the Saudi construction sector decided to adjust to current trade-market demands and rigorous constitutional regulations because of competitive pressures. This quantitative study assesses and compares existing flat design vs. mid-terrace housing through cost estimation and design criteria that takes family privacy into consideration and meets the needs of Saudi Arabian families (on average consisting of seven members). Five pilot surveys were undertaken to evaluate the property preference type of Saudi families. However, Existing models did not satisfy the medium range family needs and accordingly a 5D (3D + Time + Cost) Building Information Modelling (BIM) is proposed for cost benefiting houses. Research results revealed that mid-terrace housing was the best option, as it reduced land usage and construction costs. While, 5D BIM led to estimate accurate Bill of Quantities (BOQ) and the appraisal of construction cost