Enhanced Ductility and Toughness of Desert Sand Engineered Cementitious Composites

Economical desert sand engineered cementitious composites (DS-ECCs) using a mixture of cement, fly ash, local desert sand, water, low-cost PVA fibers, and chemical additives were developed, aiming for a further enhancement in ductility and toughness. The mechanical behavior of DS-ECCs for two sand samples (from Mu Us and Tengger deserts, China) was determined using uniaxial tension/compression tests and three-/four-point bending tests. The results showed that desert sand-based ECCs with the designed mix ratios had better mechanical properties than the river sand-based ones. Compared with the river sand-based ECCs at 28 and 56 day, the DS-ECCs presented superior ultimate tensile and comparable compression strengths. The excellent ductility was characterized by ultimate tensile and compression strains of 3-7% and over 1%, respectively. Meanwhile, the DS-ECCs showed improved flexural properties with outstanding fracture and bending strengths (4-9 kN and 21-30 kN) and toughness. The findings of this study will further strengthen the mechanical performance of DS-ECCs and broaden their engineering applicability.