DID YOU KNOW THAT CEMENT CAN BE MANUFACTURED FROM THE BONE OF OLIVES?
A group of researchers from the Polytechnic University of Valencia, in coordination with experts from the State University of São Paulo of Brazil, have developed a new type of cement, more sustainable and economical, from olive ash and slag from blast furnaces.
"The approach is to use this bone ash in the preparation of new cements, called alkaline activation, of great mechanical performance," explains Jordi Payá, a researcher at the Institute of Science and Technology of Concrete of the Polytechnic University of Valencia.
The researchers have managed to find this type of cement, more sustainable than the traditional one but also cheaper. For its manufacture, the combustion residue of the bones and slag from blast furnaces, which in their corresponding doses is mixed with water, is ground. According to the tests carried out by the Polytechnic University of Valencia, cement contains approximately 20% of olive stone ash and 80% of slag residues.
The alkaline activation cement manufactured by the researchers of the Polytechnic University of Valencia and the State University of São Paulo of Brazil also presents very good mechanical performance. Thus, it allows to obtain sufficiently high resistances for its application in construction (about 300 kilos per square centimeter with compression), especially in prefabricated elements.
Among its novelties, the researchers highlight the substitution of the synthetic chemical reagent (of high price and with a significant carbon footprint) necessary in other alkaline activation cements investigated previously, by the olive stone ash.
In addition, the preparation of these cements does not require high temperatures, as occurs with Portland cement, where temperatures higher than 1,400 degrees Celsius are necessary.
The development of this new product (at laboratory scale) is the last result of the work that for almost ten years has been carried out by the research group in Chemistry of the Building Materials of the Institute of Science and Technology of Concrete of the Polytechnic University of Valencia.
"This is the first example worldwide in which an alkaline activation cement has been manufactured where only materials from waste are required," stresses the researcher at the Polytechnic University of Valencia.
"Our work now focuses on improving the formulation to obtain better mechanical performance and study its durability and application options," adds Payá.
There is no doubt that the reuse of waste represents a very important environmental advantage in terms of CO2 emissions. So much so that with this new construction material emissions can be reduced up to 20%, according to the calculations of the Institute of Science and Technology of Concrete.
SOURCE: Materials Letters.