Mix design and properties assessment of Ultra-High Performance Fibre Reinforced Concrete (UHPFRC)

This paper addresses the mix design and properties assessment of an Ultra-High Performance Fibre Reinforced Concrete (UHPFRC). The design of the concrete mixtures is based on the aim to achieve a densely compacted cementitious matrix, employing the modified Andreasen & Andersen particle packing model. One simple and efficient method for producing the UHPFRC is utilised in this study. The workability, air content, porosity, flexural and compressive strengths of the designed UHPFRC are measured and analyzed. The results show that by utilizing the improved packing model, it is possible to design a type of UHPFRC with relatively low binder amount. Additionally, the cement hydration degree of UHPFRC is calculated. The results show that, after 28 day of curing, there is still a large amount of unhydrated cement in the UHPFRC matrix, which could be further replaced by fillers to improve the workability and cost efficiency of UHPFRC

COVID-19 and informal settlements – implications for water, sanitation and health in India and Indonesia

Informal settlements are home to over 1 billion people worldwide and are characterised by high population densities and poor environmental conditions. The authors identify the impact of COVID-19 on existing water and sanitation practices and potential pathways for the transmission of COVID-19 in informal settlements in India and Indonesia. In the short term, there is an urgent need for mobile and contactless hand washing, washing/bathing facilities and toilets. In the long term, COVID-19 provides an opportunity to invest in centralised water and sanitation networked solutions appropriate for high-density settings to integrate those settlements into cities and improve environmental conditions and health in these cities.</jats:p