The use of concrete in civil engineering already very widespread, not only on land but also the concrete used for structure directly contactedwith water. The important point is about durability of concrete. Durability of concrete is affected by permeability and absorption. Permeability is the speed of the liquid to get into the concrete, while the uptake (absorption) is the process of entry of water through the pores. The smaller the number of pores in the concrete, the higher the compressive strength and the lower the value of permeability and absorption. Rice husk ash is Pozolan reactive material that works to improve the microstructure of the transition area interface between cement paste and aggregate. Absorptin value on the specimen showed the 1.6812% to 3.4003% and the sea water to fresh water. Value permeability test object is 5,6371.10-9 5,8211.10-9 for fresh water and sea water.