Engineering Structures and Technologies

Proposal of procedure for identification of Menétrey–Willam (M-W-3) plasticity surface of homogeneous and hollow masonry units

2019-07-05T22:42:42+00:00

The article presents the author’s proposal to determine the parameters of the Mentérey–Willam (M-W-3) plasticity surface of the homogeneous masonry elements made of autoclaved aerated concrete (AAC) and vertically hollow calcium-silicate (Ca-Si) masonry units. The uniaxial and triaxial tests of AAC samples in a standard Hoek’s cell was performed while the hollow units made of silicate were tested on a custom-made test stand. By performing statistical analyses, the shape of the meridians of the surface was determined, and then the eccentricity e of the elliptical function was identified.

Influence of HPFRCC compressive strength and confinement on concrete

2019-07-08T22:42:47+00:00

The article analyses behavior of compressed concrete cylinders which were strengthened with external high performance fiber reinforced cementitious composite (HPFRCC) layer. Two different HPFRCC materials were used for the strengthening, which differed in fiber type. Two different types of loading were applied as well. The load was transferred through the whole cross section of the strengthened element and through the core – internal concrete. Loading through the whole cross section allows to validate the mixture law. Loading through the internal concrete allows to investigate the confinement effect. Comparison of theoretically calculated and experimental strength shows that mixture law and confinement effect is valid. Confinement by HPFRCC allowed to increase the strength of concrete about 4 times, but the ultimate strain remains similar. The strength of elements loaded through the whole surface has increased much more and additionally the ultimate strain has increased too.

How to strengthen flat slabs on punching shear – traditionally with steel or innovative, by using fiber composite materials?

2019-07-08T22:42:47+00:00

In the paper the effectiveness of external steel and composite reinforcement was compared and discussed. The differences between the physical features of both materials, which are relevant for their use as additional, external reinforcement of the support zones, were presented. The results of authors’ and others experimental studies on strengthening reinforced concrete slabs by using external longitudinal reinforcement in the form of CFRP strips and steel flat bars, as well as by increasing the stiffness od support zone with steel sheets and CFRP tapes, were discussed. It was stated that moderate effectiveness of composite materials as external punching shear reinforcement resulted from higher deformability of CFRP as well as premature deboning (prior to rupture of fibers).

Modeling of the reinforcement polarization range in corrosion tests

2019-10-02T22:45:15+00:00

This paper presents the results of modeling of the potential distribution in DC corrosion tests with the application of the ANSYS Maxwell software in two models: in the form of a single long bar covered with concrete and in the shape of a fragment of the bar cut out together with the core. Material parameters used for input in the ANSYS Maxwell software were adopted from tests performed in aqueous solutions. The results of the simulation led to the conclusion that the corrosion tests on the cores cut out from the structure are universal so that regardless of the concrete conductivity and the advancement of steel corrosion processes they produce correct values of the corrosion rate. Meanwhile, the measurements taken within the structure will always require some measures to limit the range of polarization or allow its estimation.

A simplified calculation method for symmetrical loading of a single-span composite string steel structure

2019-10-14T22:45:26+00:00

The article presents single-span composite string steel structure. The article discusses the calculation method for the single-span composite string structure when the load is symmetrical, while the string and bottom cable act as absolutely flexible elements. It presents the way the displacements and the shear force in the supports are calculated for the distributed and concentrated loads. Calculations with a pre-tensioned string are provided. The results are compared with the results obtained with the finite element method program. The conclusions present the results obtained.

On morphology of built-up space

2019-10-14T22:45:27+00:00

"Book ‘On the spatial structure of architectonic objects’ review." Engineering Structures and Technologies, 11(2), pp. 74-77.