OPTIMAL DESIGN OF LOW-CARBON CONCRETE CONTAINING FLY ASH AND LIMESTONE POWDER

Fly ash and limestone powder are common admixtures in environmentally friendly concrete production. This paper proposes an optimal design method for low-carbon concrete containing fly ash and limestone powder. This design method considers the influence of strength (30, 40, and 50 MPa) and carbonization service life (50 and 100 years). The genetic algorithm was utilized to determine the optimal global solution, which satisfies different constraints and can find the decisive factor of the concrete mixture design. The analytical results are as follows: When the carbonization service life is 50 years, for ordinary-strength concrete (30 MPa), carbonation durability is the decisive factor in the mixture design, while for medium-(40 MPa) and high-strength (50 MPa) concrete, strength is the decisive factor. When the carbonation service life is 100 years, for ordinary- (30 MPa) and medium-strength (40 MPa) concrete, carbonation durability is the decisive factor for the mixture design, while for high-strength (50 MPa) concrete, compressive strength is the decisive factor. Furthermore, the CO2 emissions, compressive strength, and water–binder ratio of the optimized concrete design results are in line with the actual project, which proves the effectiveness of the proposed method.