On the use of limestone calcined clay cement (LC3) in high-strength strain-hardening cement-based composites (HS-SHCC)

Abstract High-strength strain-hardening cement-based composites (HS-SHCC) demonstrate excellent mechanical and durability properties. However, high cement content typical to HS-SHCC results not only in high carbon footprint, but also in excessive hydration heat and severe autogenous shrinkage. In this investigation, Limestone Calcined Clay Cement (LC3) was used to produce sustainable HS-SHCC. The LC3 substitution resulted in higher energy consumption during mixing and in shorter setting times of the fresh, plain matrices. Although the LC3 substitution slightly reduced the compressive strength, the formation of highly polymerized C-A-S-H gel and abundant ettringite benefited the flexural strength of the plain matrices. Additionally, single-fiber pullout experiments showed that the use of LC3 led to increased fiber-matrix bond strength and pullout energy. Finally, the replacement of Portland cement by LC3 resulted in HS-SHCC with similar mechanical performance to the reference composite, indicating a high potential for using LC3 in high-performance cement-based composites.