Sustainability has and will continue to grow within every industry especially the construction industry as we head into a future wrought with uncertainties. One of our greatest concerns as a global collective is the uncertainty of natural resources moving forward. According to P.K. Mehta’s ‘Concrete: Microstructure, Properties and Materials’, moving forward we need to build sustainably by using products and materials that don’t put a drain on our dwindling resources, harm our ruptured environment and will last the treacherous sands of time.
Sustainable concrete
As can be seen with a keen eye on any major city in the world, concrete is used everywhere. In fact, According to the World Business Council, concrete is the most used man made material in the world; furthermore, it is used twice as much as all other building material combined. Concrete is used so much because no other building material can match it in terms of effectiveness, price and performance. According to ‘The Concrete Conundrum’ published by Chemistry World, cement generates 1.5 billion tons of CO2 per year, which accounts for 5-percent of the total CO2 production in the world. Concrete also uses 1-billion tons of water. Add to that the 9-billion tons of aggregate used for concrete, which has a depletion effect on our natural resources, and we can surmise that concrete properties themselves are not going to save the environment. However, buildings need to be built and we need to use materials to build them. The solution is to build as wisely as we can keep sustainability at the heart of construction. Sustainability is the capacity to endure and maintain. As per the U.N. Brundtland Commission’s in ‘Our Common Future’, Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs. This means building sustainably, but to do so we must build durably. Concrete by nature is a durable material, but, as evidenced by deteriorating structures worldwide, does have enemies thwarting a full life. The most adverse influence on concrete durability involves the transport of fluid through the matrix. Concrete does have water resistant qualities, but is at risk without the proper precautions being taken. One of the options available is an external surface applied membrane, which come with inherent drawbacks:
There are a number of situations with which an external membrane will fail, most stemming from design errors, installation mistakes, and material limitations and defects. This of course begs the question: why not make the concrete the waterproofing barrier?
Integral crystalline waterproofing
The basic idea behind integral crystalline waterproofing (ICVV) is to prevent the movement of water by plugging or blocking the natural pores, capillaries, and cracks present in concrete. Over the service life of the structure, concrete without any admixture is expected t0 develop micro cracks that may develop into macro cracks. These cracks will allow free passage t0 mcisture, which will eventually reduce the service life 0f the structure. However, when crystalline technology is used, the passive admixture in the matrix gets activated as soon as it comes in contact with moisture in the pores and micro cracks of concrete. On activation, this admixture starts crystallization and develops a microstructure that is needle like (crystals) in concrete.
Benefits of ICW
The addition of the IOW self-sealing water—protection system transforms concrete into a powerful water-resistant barrier. The crystalline technology turns porous concrete into an impermeable barrier. The result is a structure with reduced cracking, seIf-sealing and waterproofing abilities that provide a powerful defense against water damage and corrosion of reinforcing steel. These attributes lead a concrete structure to being more durable, and are able to withstand tear and decay throughout its service life. The longer a service life can be stretched for a material or product, the more sustainable that product is. The
more sustainable a product is, the better it is for the environment, and if we institute this thinking when using a material that is readily available, less harm is caused to the environment.
Alireza Biparva
B.Sc., M.A.Sc., LEED Associate
Research & Development Manager/
Concrete Specialist
Kryton Internatienal Inc.
E-mail: alireza@kryton.com
Web: www.kryton.com
Source: Arab Water World
