Low Carbon Concrete Admixture (LCCA) formula optimization and multicriteria decision: strategy and example (C.Sarta)

The huge amount globally production of concrete (more than 30 Gton/year) makes this material one of the major sources of CO2 emissions (2.5 Gton/year), accounting for about 7-8 % of the total CO2 emissions from energy production and industrial processes (36.8 Gton in 2022).

Most actions adopted to achieve the carbon neutrality of concrete by 2050 have been addressed to reduce the carbon footprint of cement, the main ingredient. Among these, the reduction of clinker in cement can play an important role (estimated -9% of CO2 to achieve Net-zero emissions by 2050). To reduce the clinker content, supplementary cementitious materials (SCMs) are needed. SCMs are already extensively used to produce blended cements at a global scale. SCMs react slower compared to clinker and can affect the strength development of the blended material. Under such premises, the desired reduction of the clinker-to-cement ratio to produce sustainable Low Carbon Concrete (LCC) might be hardly achievable. 

Recently, the new class of Low Carbon Concrete Admixtures (LCCAs), coming alongside the already well-known building admixtures, has been claimed to increase the final strength of LCC, standing their specific purpose is the maximization of cement hydration degree. 

LCCAs are formulations of many different ingredients, such as nanocomposites of polycarboxylate-ether superplasticizers (PCEs), retardants, accelerators and other.

Because of the complexity of the matter and the variety of possible materials and parameters to be optimized, multivariate analysis techniques need to be chosen to define LCCA formulations.

Thus, our talk will be related to formula optimization through a mixture experimental design and a multicriteria decision taking strategy.