Performance of Self-Consolidating Engineered Cementitious Composite under Drop-Weight Impact Loading

This study assessed the impact resistance of self-consolidating engineered cementitious composite (SCECC) using the American Concrete Institute (ACI) Committee 544's repeated drop-weight impact test and flexural impact loading test. The investigation also evaluated the compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity of the tested mixtures. Fly ash (FA), which is typically used in common SCECCs, was partially replaced by slag (SL), silica fume (SF), and/or metakaolin (MK). Also, the microsilica sand (SS), which is the primary aggregate used in SCECCs, was replaced by crushed granite sand (CS) of different sizes to develop different SCECC mixtures. Standard SCECC mixture (made with only FA), vibrated engineered cementitious composite mixture, and traditional self-consolidating concrete (SCC) made with 10 mm coarse aggregate were tested for comparison. The results indicated that combining SL, SF, or MK with FA in SCECC mixtures can create composites with improved mechanical properties, adequate ductility, and enhanced impact resistance. The highest improvement in the impact resistance in both drop-weight and flexural impact loading tests was obtained when 15% to 20% MK was combined with FA. SCECC containing CS provided comparable performance with that of SCECC made with SS, indicating promising potentials for developing cost-effective composites. The impact resistance results in both drop-weight and flexural impact loading tests also indicated that SCECC mixtures exhibited significantly higher impact resistance compared with their SCC counterpart mixtures with comparable compressive strengths.