Don Hawkridge’s AggreBind; Sustainable Alternative to Cement
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As products are developed to be internationally used, it is important that they can be made from local products, wherever they are needed, affordable in those locations, and sustainable in all aspects. Many of these products take years to develop but are a necessity for the future of underdeveloped and overdeveloped areas. One such product, [...]
As products are developed to be internationally used, it is important that they can be made from local products, wherever they are needed, affordable in those locations, and sustainable in all aspects. Many of these products take years to develop but are a necessity for the future of underdeveloped and overdeveloped areas.
One such product, invented by Don Hawkridge, is AggreBind. AggreBind is a unique, environmentally friendly, cross-linked, water based, styrene acrylic polymer with proprietary tracers. More simply stated, it is product used to bind all types of soil, including sand, into structurally sound, sealed building products used for things such as the construction of rural roads and affordable housing.
Don Hawkridge began experimenting with solutions in 1983 after being asked to find an alternative to the ingredient cement in the construction of roads and affordable housing in South Africa. Cement is the binding, fine powder agent used in products such as concrete. The need to find an alternative was due to its cost and availability in third world countries.
Many alternatives for road construction were tested over the years, including:
- Fertilizer-based solutions
- High clay content solutions
- Bitumen-based solutions
- Polymer-based solutions
And for affordable housing:
- Wood and timber framed structures
- Glass Reinforced Cement (GRC) Panels
Each was tested but only Polymer-based solutions were further developed for road used because all the others failed in different areas. Fertilizer-based binding solutions were not successful because of the high odors released and the high heat accelerant that caused it to dry or cure too quickly. High clay content binding solutions were useful except that clay is not always a locally found product. Bitumen-based binding solutions were not further evaluated because they are not sustainable and not found on-site.
Building products were born out of necessity with the use of desert sand and fly-ash to make bricks and roads in Botswana. Whereas wood and timber structures were rejected by the local population because they felt that the structures were not safe and GRC panels failed because there were jointing issues caused from the temperatures of the internal to external components.
The research on Polymer-based solutions began in the late 1980’s and early 1990’s. Hawkridge continued his research and after returning to the UK in 1997, began working with a chemist to produce a polymer product that improved load bearing capabilities of all soils and would also increase the soil’s tensile strength, which had been an issue with polymers in the past. They developed AggreBind and also were able to produce non-fired clay bricks that meet or exceed international strength standards.
Currently research testing is being conducted to offer the manufacturing of bricks, blocks and roofing tiles from waste materials with the polymer binding agent.
“AggreBind can be used to treat and stabilize waste material including waste plastic and fly-ash, as well as oil contaminated sands. These materials are rendered inert when treated with AggreBind and can be repurposed into viable and durable construction related products.”
AggreBind is offered in a variety of colors to fit in with cultural preferences. The roads are easily constructed and service can be done by locals with hand tools and pedal-power transportation, offering employment opportunities and also reducing the cost of maintenance.
Assistant Professor, Mark McKinney of IIT stated,
“…with AggreBind, there exists the possibility to explore sustainable, cost-effective ways of building that can benefit 3rd world countries while being sophisticated, flexible and relevant enough to also be used in 1st world countries.”
Products, like AggreBind, are important for sustainable purposes, not only because they can be locally sourced but because they will not have detrimental impacts to the environment in the future.
Hawkridge experienced first-hand what the products needed to be in order to be useful to the development of third world countries:
- On-hand or insitu products must be used.
- Affordable housing to live in and raise a family must be available.
- Rural roads to move goods to market, children to school and people to medical care facilities must be available.
He emphasized that these should not be luxuries and that people deserve these very simple commodities. While keeping these three simple demands in mind he developed a product that now can be used internationally as a sustainable, affordable alternative to cement in structural products.
This kind of dedication, research and experimentation is what makes construction and new products exciting. Products that are easily found, made and implemented into all locations and that do not have negative sustainable impacts, like AggreBind, are the future in the design and construction fields.