Are you looking for sustainable building materials that will bring your building costs down significantly and improve energy efficiency? If you are a contractor, architect, or real estate developer, you want to meet today’s green building construction standards while improving performance, foamed glass aggregate may be the right solution for you. Foamed glass aggregate is becoming a modern construction material that is meeting the need in the modern building industry for more lightweight, thermally efficient, and sustainable building products.
What is Foamed Glass Aggregate
Foamed glass aggregate is a lightweight, cellular glass product produced by heating recycled glass at 800–1000°C with a foaming agent to create millions of tiny, closed air cells within the glass. This process turns a waste product like glass into a superior construction material, with unique insulating qualities and incredible durability.
The manufacturing process creates a unique cellular arrangement that gives each glass particle thousands of microscopic air cells, so it is incredibly lightweight, while maintaining a remarkable strength-to-weight ratio. These closed-cell structures provided a phenomenal thermal insulation with thermal conductivities as low as 0.07–0.08 W/mK. The end product is a granulated material with the appearance of lightweight gravel but with greatly improved performance in construction applications.
Properties of Foamed Glass Aggregate
Lightweight
Foamed glass aggregate weighs approximately 160-200 kg/m³, making it around 7 to 8 times lighter than regular concrete aggregates. This weight reduction can also decrease general structural loading on the foundations and supporting elements, which can lead to cost savings for labour and equipment.
Excellent Thermal Insulation
A closed-cell structure gives foamed glass aggregate some very good thermal insulation characteristics with values of R-2.5 to R-4.0 per inch of thickness. This insulation performance, along with the proper design, can achieve some very high-performance energy-efficient building envelopes that result in reductions in heating and cooling energy use with consistent results over time.
Compressive Strength
Foamed glass aggregate is extremely lightweight; however, it has compressive strengths of 0.7 to 4.0 MPa depending on the grade and application, and withstands typical construction loads and trafficking during installation without crushing or deforming. Thus, foamed glass aggregate can be used in load-bearing situations.
Non-combustible & Fire Resistant
Foamed glass aggregate cannot burn in a building fire. A building fire may exceed 600°C, but foamed glass aggregate will not suffer structural degradation from this exposure.
Chemically Inert & Non-toxic
This composition makes foamed glass aggregate fully chemically inert, which means it will neither chemically react with other building materials nor with environmental conditions. With this chemical stability, there is no chance of concerns with indoor air quality due to chemical vapors or leaching any harmful substances into the environment over time.
Rodent, Insect, and Bacteria Resistant
The inorganic glass provides total resistance to biological attack, including rodents, insects, and bacteria. While organic insulation materials sometimes offer a habitat for pests to nest, foamed glass aggregate will not foster a nesting environment for unwanted organisms and will not degrade over time in terms of actual effectiveness.
Dimensionally and Age-stable
This recycled construction material will never shrink, expand, or settle. The dimensional stability will not change throughout the life of the building, which also means there will be no need to replace it or to supplement the material.
Environmentally Friendly
Foamed glass aggregate is made from 100% recycled glass waste and diverts massive amounts of waste from landfills while creating a high-performance building material. The fact that waste is recycled into a product is an example of circular economy principles. The enclosed environmental aspects of an initial production process contribute to significantly less energy consumption.
Reusable
Foamed glass aggregate can be readily reclaimed and reused in new construction projects without any performance deterioration at the end of the lifecycle of the building. The reusability of foamed glass aggregate adds to its environmental benefits and economically benefits demolition and reconstruction developments.
Easy to Handle and Install
Being granular and lightweight aggregates, it has very easy handling and moves easily with standard construction tools and techniques. Installation is easy, doesn’t require complicated methods or extended cure times, thus permitting the construction schedule to flow.
Benefits of Foamed Glass Aggregate
- Cost Saving: The lightweight features allow thinner foundation walls and thus less structure; all of which can translate to significant savings in materials and labour costs. Additionally, the superior thermal performance of the product reduces the overall heating and cooling costs that will be incurred over the lifetime of the building for the building owner.
- Improved Building Performance: The product shows excellent insulation values while maintaining structural integrity, enabling construction envelopes that will use significantly less energy, which meets or exceeds modern standards for green construction. This can eventually help the building obtain LEED certifications, possibly improving the property’s value and marketability.
- Efficient Installation: Being lightweight and easy to handle reduces installation times, minimising the need for cranes and heavy equipment, and simplifies logistics. Together, this translates to reduced construction time and overall costs while obtaining superior building performance.
Application of Foamed Glass Aggregate
- Foundation Systems: Commonly utilized in foundation insulation systems, where it functions as a thermal barrier and a drainage layer while supporting the structural loads. Its best attributes for below-grade applications are evident in basement wall backfill, under-slab insulation, and perimeter foundation insulation.
- Roof and Infrastructure: Provides lightweight insulating fills in insulation systems, together reducing structural needs alongside providing thermal performance and drainage. Used in infrastructure projects, foamed glass aggregate can provide a lightweight fill for bridge approaches, retaining wall backfill, and slope stabilization.
- Specialized Applications: Provides an excellent insulating layer and drainage layer for green roof systems with its lightweight properties, reducing structural loads. It is also used as foamed glass aggregate in precast concrete production to create lightweight, insulating concrete elements for continued use in construction applications.
How to Manufacture Foamed Glass Aggregate
- Raw Material Preparation: At the start of the manufacturing process, recycled glass is collected and sorted. It will then be crushed to specified sizes and cleaned of any contaminants including metals, plastics, and organic matter. Once cleaned, the glass cullet is then mixed with controlled amounts of foaming agents, usually carbon-based materials that will give off gas when heated.
- Foaming Process: The glass mixture is then fed into high-temperature furnaces, in the order of approximately 800 to 1000°C. Once in the furnace, the glass will start to soften and the foaming agents will give off the expanding gases needed to create the characteristic cellular structure. Careful control of the temperature and timing will yield the most optimal cell formation while still maintaining the structure of the glass matrix.
- Final Processing: Once foaming is completed, the foamed material is then cooled under controlled conditions to avoid thermal shock or cracking before it is crushed and screened in order to achieve the desired particle size distributions for various applications. Quality control testing is completed throughout production to ensure consistent properties such as density, compressive strength, thermal conductivity, and size distribution.
Conclusion
Foamed glass aggregate is an innovative, sustainable building product, allowing building professionals to improve performance while achieving sustainability goals in regard to the environment. At Brick & Bolt, we recognise the critical role of innovation and understand that foamed glass aggregate would be a significant advantage in modern construction. Please reach out to our technical experts to learn more about how you can get foamed glass aggregate in your next building project to improve performance, sustainability, and affordability.
Apoorva H P Achar