Analysis of Failure Conditions for a Dynamically Loaded Composite Floor System of an Industrial Building

Abstract

Results of examination and analysis of cracks formation in a composite slab floor in an industrial warehouse hall is presented in the paper. During exploitation of the floor, on which lift trucks and presses worked, a lot of deep cracks occurred in the slab. In order to define characteristics of cracks and properties of concrete there were made different NDT examinations. Measurements of vibrations due to work of presses were also realized with aim to evaluate their possible influence on cracks formation. Static, dynamic and strength structural calculations were also made based on the model of continuous, multi-bay plate. They showed that applied slab reinforcement was sufficient and acting loads did not have to cause cracks. After 3D modelling of the building and taking into consideration the flexibility of main steel beams it was gained that in the RC floor slab over supports bending moments could occur nearly three times greater than calculated from the 2D model. Taking into consideration wrong structural model of the building led to over-loading of the floor slab, its cracking and caused a necessity of its strengthening.

Application of X-ray microtomography to quality assessment of fibre cement boards

“…Garbacz [15] and Sansalone [16] proposed to use the nondestructive impact-echo for this purpose. Also Berkowski, Schabowicz et al [18] used this method. Kaszyń ski [19] and Stawiski [20] recommend using the ultrasonic method while according to Goszczyń ska et al [21], the acoustic emission method is the most suitable for this purpose.…”

Automated control of cellulose fibre cement boards with a non-contact ultrasound scanner

“…Also Berkowski, Schabowicz et al [11] used this method to determine the depth of cracks in a steel/concrete floor. Kaszyński [12] and Stawiski [13] recommend to use the ultrasonic method while according to Goszczyńska et al [14] the acoustic emission method is the most suitable for this purpose.…”

“…An exemplary flow chart of the production process, with distinguished seven zones of the particular process stages, with the mass moisture content in the latter indicated, is presented. In each of the stages the board has different moisture content, determined by destructive and non-destructive test methods [11,36,37].…”

Non-destructive identification of pull-off adhesion between concrete layers

“…The durability of concrete structures depends on the proper bond between the added concrete layer and the existing concrete substrate layer [1][2][3][4][5]. The measure of this bond is the value of pull-off adhesion f b.…”

“…The latter, in practice determined by the semi-destructive testing (SDT) pull-off method, should amount to less than 0.5 MPa according to [6]. According to [1], in order for the tests to be reliable 1 measurement per 3 m 2 of floor surface should be taken. The check measurement in this method consists in drilling a 50 mm diameter borehole in the added concrete layer of the floor.…”