Investigation On The Stress Distribution And Flexural Strength of Structural Lightweight Aggregate Concrete



Stress distribution in lightweight aggregates concrete (LWAC) has been investigated in this research. Many studies have been already done on structural behavior of LWAC, however its properties are not well known as those of NWC. There are many provisions in different codes as equations or recommendations for designing reinforced concrete structures which are applicable for NWC. Because of different roles of aggregates in LWAC and NWC structural behavior of the LWAC needs more investigation. One of the characteristics which are applied as designing parameters is characteristic curve (stress-strain) of the concrete. In this research the stress-strain curve of the LWAC made with Scoria and Pumice has been studied.
A total of 27 concrete mixes of LWAC made of scoria and pumice were tested and their stress – strain relationships have been studied. The experimental results show that rectangular stress block required to designing of LWAC structures are need more attention. The estimated flexural capacity with existing equations in codes comparison with experimental flexural capacity in LWAC is greater which lean lead to unsafety in structures. In this study, new equations for stress- strain behavior of LWAC are presented which can lead to prediction of more safe and accurate ultimate flexural strength.