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The purpose of this paper is to describe sustainability of hollow and solid blocks in sub-Saharan Africa.

Indicators of stakeholder value are proposed for measuring block sustainability based on comparisons of user building value price and carbon emissions. Block manufacturing processes in Tanzania and Uganda are described and assessed in this context.

The results from Uganda indicate that there are economic and environmental advantages in using hollow blocks as long as they are produced to statutory compliance levels. However, where blocks are not produced to standard requirements, the results indicate that it is better to use solid blocks. This surprising result seems to indicate that blocks prepared using low additions of cement might have sufficient functional quality for simple residential building applications even though they might not meet current standard strength requirements and have low cement productivity. These results also indicate that the improvement potential indicated previously cannot be realised when hollow blocks are used for simple construction needs.

Clear benchmarks for the best practical level of cement block sustainability seem to be missing. The first reasons is that the lowest acceptable compressive strength has not been defined since standard requirements might not be relevant in the studied context. The second one is that the lowest possible practically achievable cement content with acceptable cement productivity has not been established.

Understanding sustainability can be very difficult and substantial work needs to be done to introduce operational sustainability indicators.

The results contribute to the discussion of understanding, defining and measuring sustainability.

The purpose of this paper is to present information on the construction technology used to build Dublin City Council’s (DCC’s) housing stock, with an emphasis on wall construction.

The methodology applied was a mix of literature review and archival research. The research was undertaken as part of PhD research exploring the energy upgrade of a housing stock.

The research uncovered details of the construction technology used in the construction of DCC’s housing stock, especially wall construction. These details disprove perceptions and assumptions made on the evolution of construction technology in Dublin and Ireland.

The research is limited in that it primarily focused on the period between 1887 to the introduction of the 1991 Building Regulations. Further research is required on both DCC’s housing stock and the Irish housing stock to identify the specific changes in construction technology.

It is hoped this research will be a foundation for further research on the evolution of house construction technology, and housing stock asset intelligence in Ireland.

This research provides information for researchers and professionals with an interest in the evolution of Irish house construction technology. This is an area which has not received significant attention in Irish built-environment research.

Breakthrough improvement requires management decisions, which indicates that making sense of existing opportunities is important. This is a particular challenge when the improvement is a possibility and not a problem. The purpose of this paper is to propose the practice of doing an Opportunity Study as the way to create a sense of management urgency for realising dormant possibilities.

A process-based Opportunity Study is presented consisting of a Diagnosing-Analysing-Solving (DAS) approach. Benchmarks are defined and compared with the actual performance resulting in a quantifiable improvement potential (D). Main causes are analysed (A), which leads to proposed solutions (S). The Opportunity Study practice is applied to a cement milling process, a cement plant and a supply network for cement-based building products.

Results indicate that applying DAS methodology highlights realisable opportunities in all of the studied cases. This seems to be a necessary, but not sufficient criterion to create a sense of urgency for facts based change.

The results indicate that there is need for further research for looking at the process of sense making and to what extent facts alone can drive change initiatives.

Results indicate that by a simple review, focusing on what a system can do instead of which the problems are, valuable opportunities for improvement could be detected.

The paper highlights the value of focusing on opportunities.

The need to design buildings with due consideration for bioclimatic and passive design is central to promoting sustainability in the built environment from an energy perspective. Indeed, the energy and atmosphere considerations in building design, construction and operation have received the highest consideration in green building frameworks such as LEED and BREEAM to promote SDG 9: Industry, Innovation and Infrastructure and SDG 11: Sustainable Cities and Communities and contributing directly to support SDG 13: Climate Action. The research literature is rich of findings on the efficacy of passive measures in different climate contexts, but given that these measures are highly dependent on the prevailing weather conditions, which is constantly in evolution, disturbed by the climate change phenomenon, there is pressing need to be able to accurately predict such changes in the short (to the minute) and medium (to the hour and day) terms, where AI algorithms can be effectively applied. The dynamics of the weather patterns over seasons, but more crucially over a given season means that optimum response of building envelope elements, specifically through the passive elements, can be reaped if these passive measures can be adapted according to the ambient weather conditions. The use of representative mechatronics systems to intelligently control certain passive measures is presented, together with the potential use of artificial intelligence (AI) algorithms to capture the complex building physics involved to predict the expected effect of weather conditions on the indoor environmental conditions.

Understanding the thermal performance of sandcrete hollow block walls in the tropic is very essential for occupants' well-being, productivity and efficiency, due to its widespread application in buildings in the study area. Lokoja, in Nigeria, lies in the warm humid zone with its attendant's high temperatures all year round. Thus, providing an acceptable walling material that will control the high indoor air temperature becomes imperative. This paper assessed sandcrete hollow blocks as a walling material used in Lokoja, to determine the thermal performances for effective thermal comfort of the residents.

It involves the construction of a habitable model building with the commonly available sandcrete hollow blocks in the area. One unit of Cryopak iMINI Temperature and Relative Humidity Data Logger called new generation intelligent iMINI with Serial Number and Product Code MX-CI-145–0009 and MX-HE-S-16-L was installed, to record the indoor air temperature and relative humidity data at an interval of one hour, for 12 months covering dry and wet seasons. The results of the recorded data were downloaded to an excel spread sheet for assessment and analysis throughout the seasons. The values were computed using the temperature–humidity index (THI) equation, with a view to determine the indoor thermal comfort level category.

The study revealed that sandcrete hollow block walls provide thermal discomfort of the indoor environment for both seasons, with attendant adverse effects in the comfort of the occupants. The paper concludes that proper orientation of buildings, planting of trees, use of low absorbing or reflective surface materials, application of cavity walls to receive insulation materials in between the hollow spaces provided, instead of the single walling as well as providing shading device elements, can improve users' comfort and also ameliorate the heat effect on the external surface of building transferred into the interior by conduction, radiation or convection within the area and in the tropics at large. Other thermally eco-friendly wall materials available in Lokoja includes timber, stabilized laterite–cement blocks, burnt bricks and earth-mud bricks which can be used to replace sandcrete hollow block walls. These alternative wall materials are used for construction of residential and office buildings by the colonial government of Sir Fredrick Lugard in the study area.

The application of sandcrete hollow blocks as a wall material is in vogue, not minding its thermal discomfort to the users and the environment; this is due to its availability and ease of production. The acceptability of this walling material requires holistic study to unravel the best way to reduce the thermal discomfort inherent in its application.

The author succeeded in revealing the thermal performance of sandcrete hollow blocks as walling material in Lokoja, the study area. It is a first attempt at understanding the performance for human comfort in the area. This will greatly assist the resident and other researchers to improve on the application of sandcrete hollow blocks as walling material towards ensuring that maximum indoor thermal comfort is achieved.

Traditional Iranian houses, were built of heavy, voluminous building materials resulting in massive bearing wall structures. Such buildings had fixed architectural spaces, with defined boundaries and dimensions. However, the need for adaptability was fulfilled through creating multifunctional spaces, seasonal or even daily movements in the horizontal and vertical directions of house areas, and subdivision or expansion of the primary spaces. Urbanization in Iran is leading to gradual replacement of individual houses by residential complexes and apartments in which, the use of traditional design principles was lost, while solutions to enhance adaptability in the internal layouts have not yet developed.

The paper concludes that open building may provide practical tools to enhance spatial variations in the new conditions. However, to take the first step towards this approach in Iran, some major issues such as "legal framework", "changing needs of Iranian families", "Iranian life styles" and "situation of industrial building production in Iran" have to be analyzed. Considering the mentioned factors, some recommendations for architectural design are proposed.

Life cycle assessment (LCA) has considerably contributed to increasing the environmental friendliness of buildings in developed countries. However, it is hard to find evidence on the application of LCA for buildings in developing countries; particularly, Sri Lanka. There is a lack of research to compare the status of LCA of buildings in developed countries vs developing countries. In this context, the purpose of this study aims to examine the status of LCA implementation for buildings between developed countries and Sri Lanka, a developing country.

The exploratory research was adapted, and in-depth interviews were held with LCA professionals from Sri Lanka and developed countries, respectively.

Relatively less attention has been paid to the implementation of LCA for buildings in Sri Lanka compared to the developed countries due to the time and effort required to collect life cycle inventory data and limited stakeholder understanding of the LCA. Hence, this study proposed improvements, including the development of LCA databases containing region-specific data and conducting programmes to raise stakeholders' awareness to address the gaps in Sri Lanka.

The identified LCA implementation process for buildings could be used as a guide for first-time LCA users, and it equally makes a valued reference for experienced practitioners.

A limited number of the studies formulate a comparison between the LCA for building in developed countries and developing countries. This research attempts to address this knowledge gap.

Hollow blades b for air‐screws are constructed from a metal block provided with a blind coaxial bore c first by forging, stamping or rolling to produce the requisite elongation of the block and to impart a cross‐section of desired shape. Secondly, by producing a deformation of the block wall by means of pressure exerted from the inside or from the outside, and finally to form the end a of the blade in a manner suitable for attachment to the propeller hub. When an external pressure is used the interior is filled with plastic material or fluid under pressure. Alternatively, a former or core is introduced having the desired inner shape of the blade. In another method the hollow block is placed in a mould having the required external form of the blade. Preferably the root a of the blade which is hollow is provided with a thread whereby it may be screwed on to radial pins on the hub block

Recycled concrete is an economical and environmentally friendly green material. The shear performance of recycled concrete load-bearing masonry is studied, which is great of significance for its promotion and application and also has great significance for the sustainable development of energy materials.

In total, 30 new load-bearing block masonry samples of self-insulating recycled concrete are subjected to pure shear tests, and 42 samples are tested subjected to shear-compression composite shear tests. According to the axial design compression ratio, the test is separated into seven working conditions (0.1–0.8).

According to the test results, the recommended formula for the average shear strength along the joint section of recycled concrete block masonry is given, which can be used as a reference for engineering design. The measured shear-compression correlation curves of recycled concrete block masonry are drawn, and the proposed limits of three shear-compression failure characteristics are given. The recommended formula for the average shear strength of masonry under the theory of shear-friction with variable friction coefficient is given, providing a valuable reference for the formulation of relevant specifications and practical engineering design.

Simulated elastoplastic analysis and finite element modeling on the specimens are performed to verify the test results.

Heat gain in buildings occurs due to heat transfer through the building fabric or envelope, especially the walls and roof. The purpose of this paper is to identify and recommend the suitable wall materials for better thermal performance in buildings in warm and hot climatic zones of India. As India lies between the tropic of cancer and the equator, the solar radiation from the sun falls more on the walls than the roofs of the buildings. Thus, it is imperative to protect the walls from heat gain to promote thermal comfort in naturally ventilated buildings and reduce the energy loads due to artificial cooling systems in air-conditioned buildings.

In this paper, an investigation of heat flow characteristics in steady-state and the transient state for five different uninsulated wall structures using computational fluid dynamics (CFD) software has been carried out. The climate conditions at Madurai, India have been considered for this study.

The findings of the study revealed that aerated autoclaved concrete (AAC) and hollow clay blocks (HCB) for external walls in naturally ventilated buildings in warm climatic regions could improve the building’s thermal performance index and reduce peak indoor operative temperature by about 6°C–7°C. The results of steady-state and transient state analysis were found to be in good agreement with the results of the reviewed literature.

Over the past few decades, only very few architects and builders have been successful in influencing their clients to accept alternate materials such as AAC blocks, HCB, stabilized earth blocks, adobe blocks, fly-ash bricks as an alternate to conventional bricks in an attempt of highlighting their benefits, such as; materials that are easily available, more energy-efficient, can withstand the extreme weather conditions, promote thermal comfort and cost-effective. This paper provides strong evidence that AAC and HCB blocks are the most appropriate materials for improving the thermal performance of envelope walls in regions where the outdoor temperatures are above 40°C.

This paper has made an attempt to identify the appropriate wall materials for effective thermal performance in warm and hot climates. A comparative analysis between five different wall types under the existing solar conditions has been analyzed using CFD simulation study in steady-state and transient conditions under summer conditions and the appropriate wall materials have been suggested. There has been no attempt carried out so far to analyze the thermal performance of different walls using 24 h transient approach in CFD.