New Eco-Friendly Mortar Reduces Heat Loss and Plastic Waste

Newcastle University researchers have created a revolutionary cement mortar mix that is more insulating and helps to combat plastic waste. The new, innovative product, which is produced using recycled PET plastic and silica aerogel, slashes heat loss in buildings by a dramatic amount, potentially cutting heating and cooling costs. Scientists show in research published in Construction and Building Materials that the green mortar is robust enough for masonry construction but makes buildings more energy-efficient.

Changing Building Construction with Greener Materials
The building trades have long pursued environmentally friendly options to replace standard materials for lower environmental effects. Standard mortar in masonry construction causes heat loss through thermal bridging—uninsulated cracks between bricks that allow heat escape. Researchers produced a low-mass, high-performance replacement material by substituting sand with recycled PET plastic and silica aerogel.

Silica aerogels due to their excellent thermal insulation property find usage in diverse areas of the building and aerospace industry. To be used in laboratory tests, different combinations of the new paste of mortar have been tested by researchers to assess how the mixture of the mortar responds in a manner to delay the thermal conductivity at the cost of its strength. 

Major Outcomes of Thermal and Strength Tests
Seven various formulations were compared to reference mortar. The best mixture was a combination of 7% untreated silica aerogels and 3% recycled plastic PET. This mixture lowered thermal conductivity by as much as 55% from that of conventional mortar.

The PET plastic utilized in the research was recycled from shredded plastic bottles, which were washed, dried, and added to the mortar mixture. The scientists tested for major characteristics such as:

Setting time – allowing the mortar to be utilized properly for construction.
Flowability – measuring workability for use in construction in building construction.
Density and strength – providing the material of the intended quality of construction.
The new mortar, being light in nature, complied with international standards of masonry, i.e., BS-EN 413-1:2011, ASTM C270-10, and AS 1012/AS 3700. This implies that it can be utilized in practical application for use in green building techniques.

Implications for Sustainable Building Practices
Production of the green mortar has profound implications for the building industry. The product is not only made more energy-efficient but also gives a plastic waste management solution. Use of PET plastic reduces the environmental impact of plastic bottles, which contribute greatly to pollution across the world.

Through enhancing thermal insulation, the mortar is capable of reducing heating and cooling expenses, and buildings can become more energy efficient. This will be advantageous for homeowners, builders, and regulators who aim to achieve net-zero energy.

Subsequent Steps: Large-Scale Testing and Collaboration with Industry
Although laboratory tests look promising, the next step will be to pilot-test the material on large-scale building projects. The researchers want to partner with building firms to raise capital and construct demonstration buildings with the new mortar mix. Field tests will give hard evidence of energy savings and whether using this green alternative is cost-effective.

Newcastle University's study is a leap in the use of recycled materials in conventional building. If used on a large scale, this technology has the potential to make construction greener and lower the environmental impact of new buildings.

Conclusion
The invention of mortar using recycled PET plastic and silica aerogel is the most significant achievement in green construction. Under this study, it was established that new materials can decrease the loss of heat, lower energy demands, and help end plastic waste globally. With additional testing and collaboration with industry partners, the green mortar may be a fundamental piece in building low-energy buildings and curbing one of the biggest environmental issues of our time.

Source and Credits
The article has been prepared using the study "New environmentally-friendly mortar reduces heat loss," published on February 18, 2025, in Construction and Building Materials by researchers at Newcastle University.