CONCRETE TECHNOLOGY
URBAN CONCRETE - REQUISITES AND REMEDIES by Shivram B Bagade, Regional Business Development Manager, BASF South East Asia Pte Ltd, Singapore The current world population of 7.6 billion is expected to reach 8.6 billion in 2030, 9.8 billion in 2050 and 11.2 billion in 2100, according to a recent United Nations report, with roughly 83 million people being added to the world’s population every year. We are witnessing rapid urbanisation and there will be major relocation of populations to urban areas in the near future. Urbanisation brings with it a lot of challenges, with a thrust on basic needs such as food supply, transport, utilities, shelter and infrastructure. With shelter and infrastructure being among the basic requirements, construction industry professionals need to be innovative in meeting this increasing demand, and in this process, concrete plays an important role. The concrete industry, by and large, is still ‘hand-crafted’ and depends heavily on manual work and on-site construction, which leads to large amount of material wastage and workforce inefficiency. Hence, we must look at newer, energy-efficient, environment-friendly materials and technologies that minimise skill inputs and deliver faster results at affordable prices. The swift shift in the dynamics of concrete, in recent years, has posed a lot of challenges for concrete technologists and concrete professionals across the globe. In the process of making modern concrete, one needs to pay greater attention not only to aspects such as the mix design but also to its performance with respect to handling, pumping, placing, finishing and curing. Durability and sustainability are the buzz words in the world of modern concrete. Durability is at the forefront in the making of modern concrete. Hence, it is essential to have better know-how on concrete-making materials, such that one can extract the best potential from these ingredients. For obvious reasons, concrete has been different in the past and is in the present, and will be in the future. Emerging trends in construction and construction practices, such as the use of alternative aggregates, demand a holistic approach by various stakeholders in the construction industry for successfully specifying and making urban concrete. Poor rheology, stickiness, workability retention, pumpability and placement of modern concrete are some of major pain points which need immediate attention. Advancements in concrete technology due to newly developed materials, such as chemical admixtures, have assisted in improving the properties of concrete and address most of the above-mentioned pain points. This article will set out to explain the requisites for making urban concrete and the remedies for overcoming challenges in this effort. INTRODUCTION Infrastructural development, urbanisation and demographic changes are some of megatrends globally and they will bring with them enormous challenges in the immediate future. Whilst an estimated population of 11.2 billion by 2100 on Planet Earth is seen as a challenge by most of us, on the other hand, this can also be considered as an opportunity for many sectors such as agriculture, construction, electronics, finance, and so on. Seventy percent of the world’s population is expected to
stay in cities. This will create a demand for more smart megacities. Currently, America and Asia have the most megacities and it is interesting to note that by 2100, Asia and Africa will have the most megacities, as we estimate 80% of world’s population will be based in Asia and Africa. The future megacities are expected to be much larger and smarter than the current megacities. Infrastructure is one of the important elements of the economy, for a community or country to function competitively and to improve the standard of living of THE SINGAPORE ENGINEER July 2020
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