Investigation of effect of maximum size aggregate on properties of durability of normal concretes

Aggregates are the major constituents of concrete and typically occupy between 60% and 80% of the concrete volume. Properties of both fresh and hardened concrete are influenced by the quality of aggregates and yet their role is often overlooked. According to studies, the permeability of concrete is the most important parameter in its durability. Several factors is effective in concrete permeability such as water to cement ratio, content, shape and texture of aggregate, type and content of cement, etc. This paper examines the effect of changes of maximum size aggregate on the durability of properties of normal concrete (with w/c = 0.55). For this purpose, after preparing the aggregate (with maximum size aggregate 9.5, 12.5, 19 and 25 mm and similar fineness modulus) and concrete, experiments were carried out on concrete including compressive strength, sorptivity, absorption, ISAT, RCPT, and RCMT. The result show that generally with decrease of maximum size aggregate increases the compressive strength of concretes and improves the durability parameters.