Study on the Secondary Interface in Microstructure of the Superfine Sand Concrete

Abstract

The superfine sand concrete application in our country has a history of more than half a century. Although we have a certain understanding about the superfine sand concrete, there are few studies of superfine sand concrete interface. This experiment made up different water-cement ratio superfine sand concrete, and used scanning electron microscope to observe the secondary interface structure, the product of interface C-S-H gel had been carried on by the energy spectrum analysis. Results show that the secondary interface microstructure of the low water-cement ratio concrete is denser than high water cement ratio, and also have certain effects on macroscopic compressive strength; C-S-H gel calcium silicon ratio in the secondary interface is between 1.5 and 2.1.