Fracture energy of fibrous-foamed concrete using V-notched beam specimens

Foamed concrete has been widely used as an alternative material to ordinary concrete due to its advantages of low density and thermal conductivity. Moreover, this type of concrete has recently been used for structural applications. Many researchers have studied the properties of foamed concrete, including its flexural strength, compressive strength and Poisson’s ratio. However, studies on fracture energy are limited. In general, fracture energy of foamed concrete is influenced by several factors that are clearly not related to the strength of concrete itself. Therefore, further studies should be conducted on the fracture energy of foamed concrete. To enhance foamed concrete performance, various types of fibres (glass, polypropylene and steel) from 0% to 1.0% of the total volume of concrete were used as an additive material in this study. The density of the produced fibrous-foamed concrete was approximately 1600 kg/m³ ±50 kg/m³. The cube specimens were tested to determine compressive strength, and three-point bending test on notched beam specimens were conducted to obtain load–deflection profile. The fibrous-foamed concrete was categorised under a strength class of 10–17 MPa. The optimum strength is in the range of 0.4%– 0.6% fibre portions, thus indicating high fracture energy for Bazant and Committee Euro-International du Beton models. However, the fracture energy value of the Hillerborg model is increased when the portion of fibres is increased. Therefore, fracture energy increases directly with the increase of fibre portion. This relation was observed for all types of fibres.