As a key input into concrete, the most widely used construction material in the world, cement is a major contributor to climate change. The chemical and thermal combustion processes involved in the production of cement are a large source of carbon dioxide (CO2) emissions. Each year, more than 4 billion tonnes of cement are produced, accounting for around 8 percent of global CO2 emissions. To bring the cement sector in line with the Paris Agreement on climate change, its annual emissions will need to fall by at least 16 per cent by 2030. Steeper reductions will be required if assumptions about the contribution from carbon capture and storage (CCS) technologies prove to be optimistic.
Yet at the same time, cement is expected to play a vital role in the expansion of the built environment, especially in emerging economies. On a ‘business as usual’ trajectory, global cement production is set to increase to over 5 billion tonnes a year over the next 30 years. Therefore the way forward is innovation in cement usage and technologies.
Given below are some highlighted innovation cement usage and technologies across the globe
Specially Shaped Concrete Blocks
The Block ARMO system allows builders to create concrete structures that are as strong as any other, but it reduces total building time by as much as 50 percent. Funded by the Mexican Council for Science and Technology, the single-module blocks can be assembled without any binders or mixtures, and their design is so intuitive that there is no need for skilled labor when using them.
Block ARMO blocks consist of six different pieces shaped similarly to jigsaw puzzle pieces. But while jigsaw puzzles are notorious time-killers, Block ARMO is just the opposite. Each piece intuitively fits into the next, with different pieces for corners, straight walls, et cetera. The only addition on top of the blocks themselves are metal rods that get inserted into the blocks’ holes every 80 centimeters.
Geometric cement residence
Haus H36 by German architecture studio Matthias Bauer MBA/s is a 3 storey villa that is located in the heart of Stuttgart. The home is constructed using an unexpected material, a type of ultra-light cement that adorns its layered facade.
“Manufactured by Tecnhopor, the concrete mix uses foam glass ballasts as their aggregate – instead of traditional gravel – so that air voids make up 25% of its matrix.”
This modernist home boasts walls that are 45 centimeters thick and requires no added padding or insulation during construction. The use of cement as a building medium ensures this home’s inhabitants are comfortable in winter and summer months.
Fusing cement with geometric glass and wood panels, Haus H36 embraces modern minimalism with its striking design.
Concrete shower drain
Looking like a shower drain that has sprouted a shrub, the Haisui planter container is designed to help highlight the resilient nature of plant life. Designed by the Mortar – Pull+Push design firm, the Haisui planter is handcrafted by Nobuhiro Sato and is intended to be placed on a desktop or anywhere else one desires.
When filled with soil, seeds and water, the Haisui planter will enable the sprouts to grow upward through the drain grates to show how a plant can overcome man made obstacles. The Haisui planter container is crafted from concrete and a steel drain cover. This makes it a beautiful but pricey addition to a modern workstation.
Facade Design is a White Concrete Lattice
The new John Lewis shopping center in Leeds, England is meant to instill in potential shoppers a sense of luxury and extravagance. The striking facade, designed by the architecture firm Acme, is made from intersecting columns of white concrete that create diamond-shaped windows throughout the exterior.
The white concrete on the facade of the new John Lewis shopping center is etched and patterned. The spaces between the concrete hold curved, diamond-shaped windows, but in spaces where the architecture does not allow for glass, the concrete facade features intricate concave or convex concentric designs.
The interior of the building maintains the same white diamond motif. It is also accented by granite parquet flooring that alternates between slate and off-white stone. The center is lit by geometrically truncated golden chandeliers.
Circular Pavilion Designs
Designed for the 2016 Venice Biennale, Pezo Von Ellrichshausen’s Vara circular pavilion is meant to represent a normal building that instills a sense of curiosity.
The circular pavilion is a deep green color and was made with “steel, cement, and painted plaster.” The fact that the structure lacks a roof makes it look more like an art piece than a pavilion, as it lacks the intended purpose that comes along with most pavilions. The structure is made up of 10 overlapping circles and has open doorways that the viewer can walk through — making it necessary for the viewer to find their way out of the pavilion much as they would a maze.
The circular pavilion is not intended to be functional but works as a unique art piece that was created to have an “unintelligible capacity to become something more than what it seems to be.”
Strong Bendable Cement
ConFlexPave is a brand new building material that trumps traditional concrete in every way. While concrete is an incredibly strong material when it comes to compression, it has a very low tolerance for flexion — in other words, it is a strong but brittle material that cracks easily if twisted. ConFlexPave is not only stronger that traditional concrete, but it is infused with polymer microfibers that allow it to bend and flex when twisted, eliminating the brittleness that plagues its older kin.
Typically, people don’t think of things made of concrete as being subjected to much twisting. Buildings and sidewalks, for example, seem quite still to the average person. However, flex-resistance is important for building materials. If a tall building sways even a few inches due to wind or seismic activity, for example, it puts tremendous pressure on the structure. ConFlexPave could potentially create safer, stronger buildings.
Glow in the dark cements
Dr. José Carlos Rubio is a scientist from the University of San Nicolas Hidalgo in Mexico who’s responsible for creating glow-in-the-dark cement.
As ‘Curbed’ reports, coming up with the design was no easy task, as the opaque nature of traditional cement isn’t capable of storing energy from light. After nine years of testing and perfecting however, Dr. José Carlos Rubio has successfully developed his own patented technology which is likely to transform how many commercial buildings are constructed.
Not only does the glow-in-the-dark cement have the ability to light public areas in a highly sustainable manner, but it can remain illuminated for up to 12 hours. In addition, the glow-in-the-dark cement is considered capable of possessing this virtue for as long as 100 years
Sound Amplifying cylindrical towers
An Occupation of Loss’ is a sonic and visual performance art installation by Taryn Simon, a conceptual artist who focuses on the power and structure of secrecy. Her new exhibit, on display at the Park Avenue Armory in New York City, is a series of 11 cement cylindrical columns with hollows in the middle that leave space for people to enter. Due to the columns’ acoustic qualities, they act as echo chambers that amplify the noise within.
Over the course of two weeks, Simon’s Occupation of Grief will bring 30 professional mourners to the columns and, each day at sunset, the mourners will express professional grief from within the stacks. The objective of the exhibit is to help observers consider the “the intricate systems that we devise to contend with the irrationality of the universe.”
Robot crafted concrete molds
The discovery of concrete allowed for a drastic reduction in building costs compared to its predecessor, brick, however, before ‘Mesh Mould Metal,’ concrete could only be molded into relatively regular shapes for use in load-bearing buildings. With Mesh Mould Metal, though, Gramazio Kohler Research has created a system that gives architects far more flexibility in designing concrete structures.
The system uses a robotic extrusion process to construct a polymer mesh that can house concrete. Through research into how concrete binds, the Mesh Mould Metal system’s polymer mesh is shaped in order to maximize the load-bearing capacity of concrete that sets around it. As such, architects can input complex, irregular shapes into the robotic process and remain confident that the completed concrete slab will have structural integrity.
Programmable Cement
Rice University Scientists have decoded the kinetic properties of cement and developed a way to “program” the microscopic, semicrystalline particles within. This turns particles from disordered clumps into regimented shapes (cubes, spheres, etc.) that combine to make the material less porous and more durable. The programmable cement will lead to stronger structures that require less concrete, thus reducing concrete production and, in turn, carbon emissions.
It stems from better packing of the cubic particles, which leads to stronger microstructures. The other is that it will be more durable. Less porosity makes it harder for unwanted chemicals to find a path through the concrete, so it does a better job of protecting steel reinforcement inside.
Old clothes and carpets fuel cement plants
Cement manufacturing is energy-intensive, and Cemex has been pushing the use of alternative fuels, which now account for 58% of its UK production. Climafuel uses household waste, including shredded paper, carpet, textiles and plastics. Cemex is also replacing cement through use of fly ash and GGBS in mixes, while byproducts of the production process – cement kiln dust and bypass dust – are being developed for use as replacements for cement in soil stabilisation applications.
Self-Healing Concrete
It’s the bane of every engineer and construction professional’s existence: concrete cracks. Once a concrete project cracks – which all will at some point – leakage can occur, disrupting the integrity of the material. Scientists at the Netherlands’ Delft University of Technology have invented bioconcrete. This is concrete that is mixed using the same techniques as traditional concrete except that it also contains specific bacteria. These bacteria generate crystals that enclose their cells. When mixed with other secretions, such as proteins and sugar, a glue-like substance is generated. When the concrete cracks, these bacteria are activated and form either limestone or calcite, a process that seals the gaps.
Recycled Aggregate and Fly Ash Concrete Mix
A new concrete mix that combines recycled materials with a tiny amount of portland cement is this year’s winner of the American Society of Civil Engineers’ (ASCE) Charles Pankow Award for Innovation. The team that developed this concrete, and was presented with the award, was St. Paul, Minn.-based American Engineering Testing Inc. (AET), and Cemstone, Mendota Heights, Minn.
The mix these companies developed features 2% portland cement—82 pounds in a 3875 pound/cubic yard mix. The rest of the mix consists of fly ash, slag, crushed recycled concrete for both coarse aggregate and sand, recycled concrete water, and admixtures. The air-entrained mix, with a water-cement (w/c) ratio of 0.45, attained an ultimate compressive strength exceeding 4000 psi and reasonable early strength.
Since 2007, Cemstone Products has worked with AET to progressively create a mix design that uses the largest practical amount of recycled materials. They started with mass concrete mixes, designing a mix with supplementary cementitious material (SCM) to control heat generation. In the construction of AET’s X-ray vault—a 3-foot-thick structure completed and put to use in 2008—the mix included additional recycled materials, such as reclaimed water and aggregates from recycled concrete. A somewhat modified mix was later used for construction of several bridges.
Conclusion
There are a number of solutions for reducing the emissions associated with cement production; all will need to be deployed at scale to meet the decarbonization challenge. Some of these solutions are well recognized and common to other sectors: for instance, the energy efficiency of cement plants can be increased, fossil fuels can be replaced with alternatives, and CO2 emitted can be captured and stored. For decision-makers, more insight is needed into the potential for scalable, sustainable alternatives to traditional carbon-intensive cement and concrete
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