Statistical and experimental study for determining the influence of the segregation phenomenon on physical and mechanical properties of lightweight concrete

Abstract

Lightweight aggregate concrete (LWAC) compaction is a critical stage during concrete production and remains one of the major problems because excessive vibration time can easily produce the segregation phenomenon. LWAC is susceptible to segregation because of the differences between the densities of lightweight aggregates and mortar, influencing the strength and durability of concrete. In the present study, the variation in compressive strength, modulus of elasticity, ultrasonic parameters and segregation indexes were obtained in LWAC compacted with different vibration time. A statistical analysis was applied for establishing the structure of the variable dependence in segregated concretes. The vibration time and the density of the lightweight aggregate used to produce the LWAC can influence the compressive strength depending on the density of the lightweight aggregate used (up to 67% in concretes produced with the lightest aggregate). Based on these parameters and the results obtained experimentally, a simplified expression to estimate the compressive strength is proposed.