Cement, Energy and Environment

The Nano cement produced is tested in terms of soundness, se ng mes, fineness and mechanical strength. A channel of experts shall be there to test the comprehensive quality control (QC) program. The Specific surface area (SSA) of Nano cement was proposed to be 6 2 3.5x10 cm /g while Ordinary Portland Cement SSA = 3112 cm2/g [17]. Alterna vely Nano cements can also be produced from ordinary Portland cements (OPC) converted to nano-sized par cles as shown in Figure 5(a). Smaller cement par cles will result in be er hydra on process and creates less large e ringites and calcium hydrates. The conversion of cement was conducted by the use of the planetary ball milling instrument (PBM). The PBM grinds the par cles due to the use of steel balls that undergo a rota onal movement within the PBM container or milling bowl. This grinding process produces considerable energy, as the steel balls come in impact with the inner wall of the vial (milling bowl). The effec ve centrifugal force produced during the rota on of the suppor ng disc and autonomous turning of the vial act on the milling charge (balls and powders) can reach up to twenty mes the gravita onal accelera on. Since the turning direc ons of the suppor ng disc and the vial are opposite, the centrifugal forces are synchronized. Therefore, the milling media and the charged powders alterna vely roll-on the inner wall of the vial, and are li ed and thrown off across the bowl at high speed [6]. Figure 5(a) Planetary Ball Mixing Concept [6] (b) Nanocement usage in a Russian Church [18] 71 Movement of the suppor ng disc Centrifugal force Rota on of mixing bowl The church “of All Saints”, built in 2005 in Dubana, Russia using nano cement grade 90, K-82.5 in thin (40 mm) domes structures.