The influence of different coarse aggregate particle sizes on the long-term performance of concrete

Abstract

The influence of different coarse aggregate particle sizes on long-term mechanical properties, durability and microstructure of concrete is studied based on Yangtze-to-uaihe Water Diversion Project. The results show that the long-term performance of coarse aggregate concrete with 5~31.5 mm and 5~40 mm particle sizes is excellent when the water-binder ratio is 0.42. Compared with coarse aggregate concrete with 5-40 mm particle size, the compressive strength and splitting tensile strength of coarse aggregate concrete with 5~31.5 mm particle size are greater, and growth rates of compressive strength at 120 d and 180 d are 12.7% and 22.4%, respectively. The growth rates of splitting tensile strength at 120 d and 180 d are 2.7% and 4.5%, respectively. Moreover, impermeability and frost resistance of coarse aggregate concrete with 5~31.5 mm particle size are better than that with 5~40 mm particle size. The porosity of coarse aggregate concrete with 5~31.5 mm particle size is lower than that with 5-40 mm particle size. And the distribution of harmful pores and multiple harmful pores of coarse aggregate concrete with 5~31.5 mm particle size is less. The overall structure and hydration products of coarse aggregate concrete with 5~31.5 mm particle size are denser. Therefore, the performance of coarse aggregate concrete with 5~31.5 mm particle size is better than coarse aggregate hydraulic concrete with 5~40 mm particle size, which can make full use of local coarse aggregate resources in the construction of water conservancy and hydropower projects.

Keywords

coarse aggregate particle size / concrete / mechanical properties / durability / microstructure