CREEP BEHAVIOR OF STEEL FIBER REINFORCED LIGHTWEIGHT CONCRETE BEAMS UNDER FLEXURAL LOADING

Abstract

Lightweight concrete reduces the dead load and the thermal conductivity of structural concrete members. The application of steel fibers improves its properties to more ductile behavior. In recent years, many researchers focused on the flexural and tensile creep behavior of FRC. However, most of the studies investigated the creep of normal-weight concrete. This paper presents a flexural creep study on lightweight aggregate concrete (LWAC) reinforced with steel fibers under four-point flexural loading. The study considered two different lightweight concretes with oven-dry densities below 1,200 kg/m3 and below 1,600 kg/m3 as well as three different steel fiber contents (0.5, 0.75, and 1.0 vol.-%). The twelve prismatic beams were tested in a cracked state under defined stress levels in a period of 490 days. The results show that there was no exponential creep rate and no failure during the test. Additionally, this study's experimental flexural creep coefficients were compared with the calculated compression creep coefficients of Eurocode 2 and with other studies using a similar test setup.