Study on long-term leaching behavior of low alkaline cement

Leaching procedure is studied on low alkaline cement (HFSC: Highly Fly-ash contained Silica fume Cement) in which pozzolanic reaction is used for decreasing pH of pore water of cement hydrate to avoid influence on rock and other materials. Leached depth of HFSC by the immersion examination with simulated groundwater in Horonobe URL was smaller than depth of ion-exchanged Water. water exchanging is smaller than that of Ordinary Poltland Cement (OPC) with the same water binder ratio, since soluble Portlandite was not produced and dissoluble Calcium Silicate components were mainly produced. Although simulated groundwater in Horonobe URL was used for immersion examination, the low alkaline cement hydrates is more durable for leaching degradation than OPC. For all cements, groundwater showed tendency of accelerate leaching compared to ion exchanged water. This study shows that HFSC has higher durability for leaching degradation to groundwater than OPC.