Developing a very high-strength low-CO2 cementitious matrix based on a multi-binder approach for structural lightweight aggregate concrete

Abstract

Structural lightweight aggregate concrete (LWAC) requires a high-strength cementitious matrix to counteract the low strength of the lightweight aggregates. This article combines synergistic SCMs and optimized mix packing densities to the cementitious matrix to simultaneously achieve high-strength and low-CO2. Metakaolin, silica fume, nano-silica, and fly ash were used in binary, ternary, and quaternary systems. The results revealed that it is possible to develop a compressive strength above 150 MPa, reducing CO2-emissions up to 43%. By combining SCMs with packing modeling, it was possible to achieve a high-strength, low-CO2 cementitious matrix that can be used in high-performance LWAC in the future.