Concrete is one of the most widely used building materials. It makes very strong and robust constructions which last for years and centuries. Although it has low tensile strength, it’s commonly strengthened using steel. Besides clear benefits, concrete has some significant and also lesser known disadvantages when used in construction. It has been recently suggested that concrete isn’t in fact as strong as we would expect. This is due to climate change and its effect on concrete deterioration. Roman Colosseum has lasted for centuries, however, modern reinforced concrete is not likely to survive for as long. Main reasons for decays are acid rains, CO2 in the atmosphere and changes in temperatures, all negatively impacting steel structure. On the other hand, concrete also has a significant impact on the environment, such as contribution to CO2 concentration. Luckily, there is plenty of other, greener, building materials that are promising alternatives.
Straw Bale Construction
Straw bale houses are cost-efficient, walls have high insulation and straw is an agricultural by-product. Moreover, straw is readily available and in close proximity to most European and US locations. Straw buildings are unique and beautiful, what isn’t usually the case for concrete buildings. If you’re looking for a house that is cool in the summer and keeps warmth in the winter, straw is one of the materials worth looking into.
Although grasscrete doesn’t eliminate use of concrete, its significant benefit is reduction of quantity of concrete. It is a method of laying floors, parking lots, paves and pavements in such a way to allow grass or other plants to grow through the open spaces. Concrete makes up 47% of the Grasscrete and remaining 53% constitutes of grass in holes. Alternatively, when grass isn’t a desirable filling component, other materials can fill up the holes. These include crushed stone and seashells. Grasscrete has a great advantage of allowing quicker and more efficient absorption of water.
Rammed Earth Technique
Rammed Earth is a technique in which raw materials, including chalk, lime, soil and earth constitute building materials for construction of houses and walls, amongst other applications. Although its tensile strength is lower than that of concrete, rammed earth materials can be safely used in construction of houses. Reinforcement with rebar, bamboo or wood helps prevent building failure caused by earthquakes and heavy snowfalls. It has great advantage of absorbing and storing heat and releasing it when the temperature falls, which reduces the need for heating and air conditioning. Even better, this is probably one of the building materials with lowest environmental impact – and we all want to switch to greener and leaner solutions.
Ferrock promises even stronger and more durable constructions than those made with concrete. What’s more, this alternative is a way greener option. Its name reflects its composition: it’s an iron-rich ferrous rock. It is made of steel dust left over from industrial processes. Another element is silica from glass. Iron carbonate forms in the reaction of iron from steel with CO2. Ferrock is not only 5 times stronger than Portland cement, but is also more flexible. Those characteristics make it ideal for use in seismic zones. Being a carbon-negative material, it also absorbs and binds CO2 instead of emitting it. It is a very promising approach and hopefully is a step towards a more sustainable future with building materials based on improved technologies.