Mechanical Properties and Microstructure of High Performance Lightweight Concrete.

High performance lightweight concrete (HPLC) characterized by low density, high strength and good durability, has prosperous application prospects in civil engineering. In this experiment, the modified Andreasen and Andersen model was used to design the initial mixture of HPLC. Shale ceramic sand (SCS) with different content was used to replace lightweight internal curing sand to prepare HPLC. The effect of different content of SCS on workability, mechanical properties and durability of HPLC were systematically investigated. In addition, this work explored the effect of SCS on the micro-morphology and pore structure of HPLC. It is found that: 1) When the replacement rate of SCS is 100%, the apparent density of HPLC is 1 848. 3 kg/m³, and its compressive strength is 123. 22 MPa. 2) The addition of SCS can improve the mechanical properties of HPLC, and the compressive strength, flexural strength and elastic modulus of HPLC increase by 8. 88% ~ 47. 92%, 22. 50% ~ 56. 30% and 3. 49% ~ 14. 03%, respectively. 3) SCS can improve the durability of HPLC. When SCS replacement rate is 100%, the chloride migration coefficient of HPLC is reduced by 32. 52%, compared to the control group. 4) Due to the addition of SCS, the microstructure of HPLC is significantly improved, and the porosity of HPLC reduces by 14. 86% ~28. 24%. [ABSTRACT FROM AUTHOR]