Study on long-term leaching behavior of low alkaline cement

Hitomi, Takashi*; Iriya, Keishiro*; Nakayama, Masashi ; Sato, Haruo

Leaching procedure is studied on Low alkaline 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 Low alkaline cement (HFSC) by the immersion examination with Horonobe simulated ground 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.