Reactive-transport evaluation for alteration of granite under alkaline conditions

Kirino, Yusuke*; Nakashima, Satoru*; Yokoyama, Tadashi*; Sasamoto, Hiroshi   

Cementitious grout materials will be used to reduce groundwater inflow during excavation and construction of drifts for deep geological disposal of high lever radioactive waste. High alkaline solution derived from cementitious materials could alter the host rock surrounding the engineered barriers. In the present study, the experiments of interactions between the alkaline solution and the granitic rock (10 10 5 mm block sample) were conducted to understand the evolution of rock properties. The surface of granitic block sample is assumed the fresh fracture surface and the inside of block sample is regarded as rock matrix. Evolution and distribution of alteration products were estimated by both the accelerated laboratory experiments and the computer simulations considering reactive-transport processes.