Effect of Biological shells aggregate on the Mechanical properties and sustainability of concrete

Abstract

To solve waste bio-shell and put them into recycle, the researchers proposed using waste bio-shells as aggregate matrix for concrete. In order to determine the substitution amount of shells, the researchers used the orthogonal experimental method, and designed shell concrete experiments with gradient substitution rates at 10%, 30% and 50%, with a total of 78 groups of specimens. By analyzing the tensile, bending and frost resistance of these specimens, the experimental data show that adding shells as aggregate at 10%, 30% or 50% can improve the mechanical properties of the concrete, the maximum flexural strength can be increased by 3.96Mpa, the maximum compressive strength can be increased by 2.5Mpa, but with a degradation of frost resistance. With the investigate of economic performance, it was found that the costs of frame-shear structure, frame structure, and tube-in-tube structure were reduced by 10.2%, 10%, and 10.3% respectively. In the carbon environmental assessment, the carbon reduction of a single specimen with 10%, 30%, and 50% shell addition were 0.003, 0.0010, and 0.0015 kg respectively. In summary, compared with ordinary concrete materials, it is very possible to use waste bio-shells as a substitute for aggregates to develop the sustainable recycling development of concrete materials.