The feasibility of using electromagnetic waves in determining membrane failure through concrete

Concrete flat roof defects such as water leakage present a significant and common problem in large buildings, particularly in tropical countries, where rainfall is high. To monitor this condition, effective non-destructive test methods are required to detect problems at an early stage, especially hidden defects within the concrete roof, which are critical. This paper presents the potential use of electromagnetic (EM) waves for determining possible leakage of the concrete flat roof as a result of failure of the waterproof membrane layer. This study was assessed, experimentally by investigation of the propagation of EM waves through the roof and their interaction with water. Novel Microwave sensors described in the paper operate in the 6 GHz to 12 GHz frequency range using a Marconi 6200A microwave test set. A range of existing methods was reviewed and analysed. Results of experimental tests confirmed that microwaves could be used as an alternative non-destructive method for identifying water ingress caused by membrane failure into the concrete roof surface

Sustainable Construction Technologies: Life Cycle Assessment.

The building and construction industry has become the focus of environmental impact reduction in the aftermath of the global resolution to reduce its adverse effect and make the built environment more sustainable. This chapter examines the place of materials in sustainable building construction generally and from the perspective of life cycle assessment and reduction of environmental impact. Hence, specific approaches to sustainable construction from the perspective of materials such as improved material production processes, recycling, materials substitution, innovative construction methods, deconstruction, use of innovative materials, and use of eco-friendly materials are explained from the life cycle impact perspective. The implications of the approaches for improved uptake of sustainable construction practices are also examined with particular reference to the role of policy framework and legislatio

An Investigation of Lightly Profiled Sandwich Panels Subject to Local Buckling and Flexural Wrinkling Effects

Sandwich panels exhibit various types of failure modes depending on the steel face used. For the flat and lightly profiled sandwich panels, flexural wrinkling is an extremely important design criterion as the behaviour of these panels is governed mainly by flexural wrinkling. However, in the lightly profiled panels, when the depth or spacing of the ribs increases, flat plate buckling between the ribs occurs leading to the failure of the entire panel due to the interaction between local buckling and flexural wrinkling modes. Current design formulae for sandwich panels do not consider such interactive buckling effects. To obtain a safe design solution, this interactive buckling behaviour should be taken into account in the design of lightly profiled sandwich panels. Therefore a research project was undertaken to investigate the interactive buckling behaviour of lightly profiled panels with varying depths and spacings of the ribs using a series of experiments and finite element analyses. A new improved design formula was developed for the safe and economical design of lightly profiled panels that takes into account the interaction between local buckling and flexural wrinkling. This paper presents the details of this investigation, the results and the new design formula

Appendix 7 to "The Status of Biological Invasions and their Management in South Africa in 2022"—The Species List for the Prince Edward Islands

<p>SANBI and CIB 2023. Appendix 7 to "The Status of Biological Invasions and their Management in South Africa in 2022"—The Species List for the Prince Edward Islands.  South African National Biodiversity Institute, Kirstenbosch and DSI-NRF Centre of Excellence for Invasion Biology, Stellenbosch. http://dx.doi.org/10.5281/zenodo.8217229</p> <p> </p> <p>For more details see: http://iasreport.sanbi.org.za<br> For the report itself see: http://dx.doi.org/10.5281/zenodo.8217182</p&gt

Appendix 2 to "The Status of Biological Invasions and their Management in South Africa in 2022"—The species list

<p>SANBI and CIB 2023. Appendix 2 to "The Status of Biological Invasions and their Management in South Africa in 2022"—The species list. South African National Biodiversity Institute, Kirstenbosch and DSI-NRF Centre of Excellence for Invasion Biology, Stellenbosch. http://dx.doi.org/10.5281/zenodo.8217197</p> <p>For more details see: http://iasreport.sanbi.org.za</p> <p>For the report itself see: http://dx.doi.org/10.5281/zenodo.8217182</p&gt