Mechanical and Microstructural Properties of Ultra-High Performance Concrete with Lightweight Aggregates

Although ultra-high-performance concrete (UHPC) presents superior mechanical properties and durability compared to conventional concrete; its spalling resistance elevated temperatures is much lower due the high compactness absence of capillary pores. This paper investigated influence lightweight aggregate (LWA) on strength microstructure UHPC enhance temperatures. specimens prepared with LWA as a partial replacement silica sand were produced. The study evaluated compressive flexural strengths, failure mode, mass loss, specimens, using SEM. results showed that specimen was reduced increasing content at ambient temperature, but improved when exposed 10% led an increase in from 100 MPa 110 after exposure 200 °C; however, decreased 23.6 18.3 MPa. On contrary, increased inclusion temperature high-temperature exposure. mode not significantly affected by variation temperature. In addition, SEM result confirms effective internal curing material for enhancing