The effect of carbon nanofibers on fresh and mechanical properties of lightweight engineered cementitious composite using hollow glass microspheres

Hollow glass microsphere (HGM) according to the preferred embodiments may be used as fillers in composite materials, where they impart properties of cost reduction, weight reduction, improved processing performance enhancement, improved machinability and/ or improved workability. More specifically, the HGMs may be used as inorganic cementitious materials, concrete systems, and ceramics. On the other hand, carbon nanofibers (CNFs) are becoming domination in the market of nanomaterials because of its unique properties and its potential to reinforce cementitious materials. To take advantage of both the low density of HGMs and the high mechanical performance of CNFs, this study aims to develop lightweight engineered cementitious composite (LWECC) by adopting a novel material combination of HGMs and CNF. By replacing 40% of fly ash with HGMs, this study successfully developed LWECC mixes with desirable workability and density due to the smooth surface, spherical shape and low density of HGM. Due to the extra reinforcement effect of CNF, the developed LWECC composite is able to achieve lightweight without disturbance of mechanical strength compared to normal weight ECC. The newly developed LWECC is able to achieve a density less than 1820 kg/m(3) with compressive and flexural strength up to 48 MPa and 8 MPa, respectively.