Department of Civil and Environmental Engineering Researchers at Idaho State University have gone on to conduct a recent study that goes on to reveal that by replacing a segment of the cement that gets typically used in concrete with precipitated calcium carbonate- PCC which happens to be a byproduct of refining sugar beets into refined sugar, it is indeed possible to maintain the strength of the concrete at a level comparable to that of traditional concrete. PCC happens to be chemically inseparable from its naturally occurring counterpart, which is limestone. As of now, cement manufacturers go on to produce cement by heating a mixture of limestone, clay, as well as other materials and thereby subsequently grinding them into a fine powder. As per a 2018 report by the think tank Chatham House, the production of cement happens to be responsible for approximately 8% of global carbon dioxide emissions.
Associate professor in the Department of Civil and Environmental Engineering and an expert in structural engineering, Mustafa Mashal, stated that he went on to acquire knowledge on precipitated calcium carbonate from Joe Shurtleff, who happens to be an undergraduate civil engineering student. There has already been a recent effort made to investigate eco-friendly alternatives to decreasing the amount of cement which is used in concrete. This prompted Mashal to consider exploring this particular material as a potential partial replacement when it comes to cement.
So as to test the hypothesis, the research team went on to conduct a series of small-scale tests in case of samples of concrete. Each sample had varied amounts of PCC, and there also happened to be control samples of conventional concrete included in the study. It has been discovered that up to 30% of the cement that is used in concrete can be substituted with precipitated calcium carbonate, and that too at the same time meeting the standards set by the American Society for Testing and Materials.
It is well to be noted that the research team not only explored greener possibilities for cement but also investigated the use of upcycled concrete aggregate as an alternative to the commonly used sand or crushed stones as aggregates as well. Upcycled concrete aggregate refers to concrete pieces that have been previously used as well as crushed to the desired sizes for a particular project. The results indicated that it is indeed possible to replace up to 100% of the aggregates with upcycled concrete without even compromising its strength. The report released in 2020 by the Environmental Protection Agency states that concrete accounts for 381 million tons, which is almost equal to two-thirds of all demolition debris found in the US.
A graduate student studying civil engineering and the lead author of the study, Kabiraj Phuyal, stated that conventional concrete production results in major carbon emissions and requires substantial raw materials worldwide. Addressing environmental concerns happens to be crucial when it comes to exploring greener as well as more sustainable options for concrete production. Furthermore, the concrete that has been tested has the potential to offer builders a more cost-effective choice due to its utilization of upcycled as well as recycled materials.
Though the outlook for greener concrete looks promising indeed, it still has to undergo further testing. Interestingly, researchers will continue testing this new environmentally conscious concrete mix so as to evaluate its resistance to freeze-thaw conditions, surface hardness, along with other factors. The idea is to determine its complete durability and also assess its ability to withstand real-world conditions.
Mashal went on to state that they do have intentions to expand their research and delve into more aspects of this environmentally friendly concrete. These aspects utilize recycled materials and by-products that they happen to have developed at ISU. They are currently working in collaboration with industry partners so as to identify potential applications for these concrete mixes.
Working on this project happens to be an exhilarating as well as fulfilling experience, and it was a fantastic opportunity to apply the knowledge and skills he has gone on to acquire in the field of eco-friendly construction, said Phuyal.
