Determination of material and elasticity constants of cement fibre boards to extend field of application

Abstract The paper aims to determine selected basic material and elasticity constants of cement fibre boards (CFB) with organic cellulose fibres produced with the use of Hatschek process and thus extend potential field of application of CFB in the field of civil engineering for supporting structure designs. Modulus of rupture and modulus of elasticity determination was performed with the use of a three-point and four-point bend test, and tensile strength and compressive strengths were tested. During loading the orientation of testing specimens was distinguished, while taking into account the production method. The loading was applied with regard to a potential use of the boards in supporting structures perpendicularly or parallel to the mid-plane of the board. An innovative approach to distinguishing board orientation during loading was selected in order to extend the scope of application of this special group of cement composites even outside the usual field of application, particularly with a focus on bearing structures of building construction. The testing specimen orientation had a significant effect on failure and course of loading diagrams. The biggest differences occurred under tensile loading, when delamination of thin layers (monolayers) of the cement fibre board occurred during perpendicular loading to the board mid-plane.