The paper deals with the development of the magnetic method using permanent magnets for monitoring the distribution of fibers in hardened steel fiber-concrete structures and comparative measurements on test samples.
Wood is an organic material and therefore often considered to have a short lifetime. However, in the past, people did not distinguish between durability of wood and durability of masonry, proof of which is the existence of constructions that combine the use of both. In fact, the lifetime of wood can be high if specific rules are followed when designing the construction.
This paper presents an analysis of the behaviour of wood when using the diagnostic tool for "in-situ" assessment of wood based on the principle of mechanical resistance to penetration tool (mandrel) into the wood. The aim was to describe the degree of deformation and failure mode during penetration (diameter 2.5 mm) into wood in a purely radial direction and to compare the tool with a standard measurement unit testing on samples.
Wood-destroying insects is one of the biological wood pests. Attacks the wood material, both individually and also in parallel with other decaying biological pests. Knowledge of principles for the design and implementation of a hot air disposal of wood-destroying insects is necessary for the reconstruction of historic buildings. Carefull consider from a conceptual point of view is necessary for the design for redevelopment of wooden elements affected by wood-destroying insects.
This paper deals with the influence of addition of fine-grained ceramic body which was added to the lime mortars in the amount of 0–50 % of the binder weight. The addition effect of the fine-grained ceramic body on the properties of the modified lime mortars was evaluated on base of the strength and absorbency characteristics of the modified lime plasters. The ceramic body was analyzed prior to its use in the mortars. Pozzolanic activity and mineralogical composition were determined. The results showed that the addition of the ceramic body in the modified lime plasters had positive influence on their properties. The strenghts of the modified lime plasters were increased and the absorbency was reduced.
Relatively frequent request when conducting construction surveys of historical constructions is to determine the origin and age of bricks as well as their physico-mechanical properties in the context of a static evaluation of the brickwork. This article addresses this issue using an example of historic brickwork in a bridge construction.
An amendment of the Building Act will bring many changes to developers and building offices. Procedures of the Building Act will be simplified in a lot of cases. Some parts of the Building Act are modified in detail. This amendment has been published in the Collection of Laws under No. 350/2012 Coll .. and it will be effective from January 1, 2013.
The article describes unbiased comparison between two different methods of building protection against subsurface water and moisture – the foundation structure of waterproof concrete and waterproofing envelope based on the bitumen or plastic continuous sheet water proofing. The confrontation of properties and risk factors of the methods is made from the perspective of waterproof concrete structure which is the main content of the article. The comparative analysis is supplemented with the photos from field surveys and the results of independent laboratory tests.
Cracks in industrial concrete floors with top layer of mineral granules are quite common. Their evaluation depends largely on the subjective opinion of the assessors. It is not the exception that the cracks appear after a longer time in the order of weeks to months after the construction. At the time up to three years after construction there is a tendency of their expansion. Cracks have a major impact on the life of industrial concrete floors.
This paper deals with the issue of comparing simulations for steady and unsteady thermal state at the massive structures. In this paper, computer simulations are compared with real measurements and measurements of climatic data. The evaluation showed that the steady-state temperature can be comparing with real model used after the end of the accumulation phase. It is evident that the requirements for the temperature factor of the internal surface of the solid structures, set by legislation, are a safe assumption.
Standards for the building of steel structures in recent years undergone a similar development as the standards for the design of steel structures. System of the Czech standards was supplemented by EN 1090 standard, that became CSN EN 1090. Subsequently, duplicate Czech standards were repealed and replaced by the so-called residual standards, which include provisions that were in the original Czech standards but are not in the standard European.
Video Image Fire Detection is a modern fire detection mechanism of phenomena and processes accompanying fire. Main advantage is the ability and speed of smoke detection, independent of the arrival of the smoke to the sensor. Video Image Fire Detection can achieve higher sensitivity than conventional fire sensors by simultaneously monitoring different parameters in a large area. The article gives basic requirements for Video Image Fire Detector for Automatic Fire Alarm Signaling.
The behaviour of real structures in some cases differs from the structure modeled in computational program. Article deals with the influences that can affect the characteristics of the structure, so that they affect the surface temperature of the structure. In particular, the moisture inside the material and air humidity.
Development of wooden buildings in the Czech Republic is based on the requirement to implement the most low-energy buildings. Still there are many people who are afraid of wooden buildings mainly because of their misconceptions about their behaviour under fire. But the truth is that in a fire wood doesn’t lose its rigidity and strength, and the remaining sections of wood elements are also able to carry the load.