INGENIEUR
INGENIEUR
challenges. Earthen homes are generally best suited to hot and dry climates, since earth is a thermal mass and responds well to daily and seasonal changes in temperature. Structurally, earth has good load-bearing and compressive strength, but is much weaker when it performs in tension. Additive materials like straw( used to make cob) will enhance tensile capacities while structural frames made from wood or bamboo( used for rammed earth and adobe) can absorb perpendicular forces. Tensile and structural reinforcement also improves resistance to certain climatic challenges such as strong winds and earthquakes though generally earth may not be the best choice in disaster prone areas.
Different types of earth constructions have varying abilities to tolerate humidity and water. Long roof overhangs, finishing materials such as cement or plaster and high foundations will all help to protect earth structures from water. For all kinds of earth construction is it important that the quality of the soil be assessed before using it. Mineralogical composition, grain shape and size, and particle distribution all affect soil quality and the overall durability of the finished structure.
Responsible sourcing of soil, sand and clay should be considered since extracting from certain sites such as riverbeds can have negative environmental impacts like increasing erosion.
MCKINSEY & COMPANY
The McKinsey Global Institute estimates that the world will need to spend US $ 57 trillion on infrastructure by 2030 to keep up with global GDP growth. This is a massive incentive for players in the construction industry to identify solutions to transform productivity and project delivery through new technologies and improved practices.
Disrupting construction- Five big ideas All five ideas are grounded in innovations that are applicable to the construction sector and that are either being deployed or prototyped. In short, they are practical and relevant. Moreover, they are designed to work together to deliver greater impact:
1. Higher-definition surveying and geolocation- Rapid digital mapping and estimating
2. Next generation 5-D building information modelling – Design platform for the future
3. Digital collaboration and mobility – Moving to paperless projects, from the office to the workforce.
4. The Internet of Things and advanced analytics – Intelligent asset management and decision making
5. Future-proof design and construction – Designing with materials and methods of the future.
Building materials represent a US $ 1 trillion global industry; materials usually account for more than half the total cost of projects. Traditional materials such as concrete, cement, and asphalt make up most of this demand. But new and better construction materials are also required due to several trends:
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Green construction. There is an immense push to adopt materials and technologies with lower carbon footprints.
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Cost efficiency. Given substantial cost pressures, there is a need for structural change in the choice of materials, in addition to incremental lean efforts.
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Supply-chain agility. Transporting heavy materials and equipment has massive implications on supply-chain costs and time, especially because many new projects are located in remote or dense areas.
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Improved durability and strength. With capital costs rising and land growing scarce in many markets, owners are insisting that projects have longer commercial lives.
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Off-site construction. Assembling lighter, easier-to-handle materials off-site can improve project efficiency, address onsite space constraints, and create the conditions for crews to improve their skills.
There has been a wave of innovation in construction materials over the past few decades, developed with specific uses in mind. There are dozens; here are a few that are particularly interesting: Self-healing concrete. This uses bacteria as a healing agent to close cracks on concrete; it is currently at the proof-ofconcept stage. Concrete canvas. Take a layer of“ concrete cloth,” then add water and allow to set. This innovation typically is used for drains,
76 VOL 69 JANUARY-MARCH 2017