Investigation of micro-cracks and microstructure of high performance lightweight aggregate concrete

This paper aims at studying the relationship between micro-cracks, performance characteristics and microstructures of high performance lightweight aggregate concrete (HPLAC) under freeze–thaw cycling effect. The studies on the durability phenomenon and micro-cracks are conducted using scanning electron microscope, energy spectrum analyzer and infrared spectrum analyzer. Dynamic modulus of elasticity has been measured to assess damages to the hardened HPLAC. It is discovered that the micro-cracks formed within HPLAC is the major factor determining its durability. The addition of water reducing agent and admixtures can help increase the density of the microstructure and thus improve the durability of concrete.