Concrete's durability is the key factor that affects the service life of the concrete structure. One factor that affects the durability properties of concrete is its pore structure, which can be investigated by analyzing the materials' absorption rate. For the structures with direct contact with water, water absorption can change the pore structure's behavior, affecting the durability of the conc in the long term rate. It is important to research to find the water absorption properties of concrete with different mixtures.This research investigates the rate of absorption of concrete by using fly ash and silica fume. Based on secondary absorption properties, the result shows that 15% fly ash in normal concrete increases the resistance to water penetration by 23%. The usage of 5% Silica Fume increases the resistance by 11.8%. The usage of 5% silica fume + 10% fly ash increases the resistance by 16.2%. It shows that the use of supplementary materials in concrete increases the resistance of water penetration. In this research, the usage of 15% fly ash as cement replacement shows the best result.

Diffusion is one of the the main mechanisms of fluid ingress into the concrete. However, in partially saturated concrete, the fluid will mainly be absorbed by the capillary suction mechanism, which associates with the sorptivity properties of the concrete. This paper presents the results of an experimental program to investigate the influence of Portland cement substitution with Silica Fume (SF) and Type F Fly Ash (FA) on the rate of absorption, which also known as sorptivity, and chloride penetration of concrete. The sorptivity of the concrete was evaluated according to ASTM 1585, while the chloride penetration was evaluated according to ASTM C 1202. By substituting part of cement with FA and SF, it was found that the sorptivity of concrete is reduced. Furthermore, all type of concrete with supplementary material, including CFA, CSF and CSM, is confirmed to enhance the ability of concrete to resist chloride penetration compared yo normal concrete (NC).