National Repository of Grey Literature 60 records found  beginprevious49 - 58next  jump to record: Search took 0.00 seconds. 
Lime Mortar for Repair of Historic Buildings – design based on “copy” of original mortar
Válek, Jan
When repairing historic buildings, it is possible to consider designing a new mortar as a copy of the historic one. The paper deals with this approach from different viewpoints.
Characterisation of historic mortars. Determination of characteristic properties with respect to repair
Válek, Jan ; Slížková, Zuzana ; Zeman, Antonín ; Frolík, J. ; Bruthans, J. ; Chotěbor, P. ; Měchura, P.
Paper presents approach to characterisation of historic mortars, which is a part of a project that aims at a development of an advanced parametrical data base of properties of historic mortars and renders. The project develops its own method of sampling and selects the information to be collected.
Weathering processes on selected structural elements of St. Vitus´ cathedral at Prague Castle
Zeman, Antonín ; Válek, Jan ; Slížková, Zuzana ; Korbelová, Z.
The summary of results of treatment sulfor dioxide on pier of St. Vitus´Cathedral. The main used methods were macroscopic description with photodocumentation, petrographical research, research in polarization microscope and spectroscopy.
Tests for desing of mortars and renders compatible with existing historic material
Válek, Jan ; Slížková, Zuzana
Design of masonry mortars and renders for repair of historic structures includes tests and testing procedures which serve for evaluation of compatibility between existing material and repair mixtures. Paper describes current possibilities of tests and analysis of historic and new mortars. The authors stem from published definitions of compatibility and emphasize a necessity to take into account also more detailed technical specifications, e.g. position of evaluated material in structure, type of structure, material exposure conditions, degree of deterioration of material and its ability to serve its original function.
Information about activities of RILEM Technical Committee TC 203 RHM 'Repair mortars for historic masonry'
Válek, Jan
This article aims to introduce the activities of RILEM Technical Committee 203 RHM on Repair mortars for historic masonry to Czech researches and professionals. TC 203RHM deals with four main topics: classification of mortar-function of mortars in masonry, classification of problems (masonry-mortar interface), development of technical requirements and test methods. The main scopes of work of the four TC’s workgroups are introduced in this paper
Mechanical and physical tests on lime mortars with metakaolin and their suitability for repair of protected historic monuments
Válek, Jan ; Slížková, Zuzana ; Zeman, Antonín
Mechanical and physical tests on lime mortars with addition of metakaolin from new sources in the Czech Republic were carried out in the laboratories of the Institute of Theoretical and Applied Mechanics AV CR during 2004 to 2006. The tests results were used for design of optimised calcining temperature of kaolin, proportion of gauging between lime and metakaolin, and evaluation of influence of addition of Portland cement. Discussion of the results includes suitability of metakaolin gauged lime mortars for repair of historic monuments.
Výkonné restaurátorské materiály inspirované historickými maltami
Drdácký, Miloš ; Slížková, Zuzana ; Válek, Jan ; Zeman, Antonín ; Michoinová, D. ; Krage, L. ; Bosiljakov, V.
Poster reviews scientific evaluation of characteristics of historic mortars, presents knowledge of behaviour of lime mortars with natural fibres and results of research into lime mortars with pozzolanic additives.
Expert opinion on materials selected for repair of jointing mortar and stone masonry of Charles Bridge
Válek, Jan
The report deals with evaluation of suitability and compatibility of materials designed for repair of joints of Charles Bridge stone masonry.
DELIVERABLE D9.6 Small sample testing
Cikrle, P. ; Drdácký, Miloš ; Lesák, Jaroslav ; Slížková, Zuzana ; Válek, Jan ; Vavřík, Daniel ; Zíma, Pavel
A number of in-situ tests for mechanical material properties is readily available but there were developed improved methodologies which met the requirements and specifics of this project. It the case of historic masonry there was necessary to deal with a common additional problem, which is the testing of non-standards samples. This was for example a problem of testing of historic bedding mortars or renders, where a typical width of sample is around 10 mm. It comes along with the general need for small ů micro samples with regards to the protection of historic masonry where a minimum intervention is always required. Mechanical properties in bending were tested on non-standard mortar samples which were supplemented symmetrically on both ends with two 'prostheses'. According to the results of the tests comparing the flexural strength of pure mortar beams with the strength ascertained on prosthesized identical material the influence of prosthesization is negligible. Testing of stone samples involved comparison of the compressive and split tensile strength of specimens of standard dimensions and specimens of smaller dimensions
DELIVERABLE D9.5 Damaged Masonry
Drdácký, Miloš ; Lesák, Jaroslav ; Urushadze, Shota ; Válek, Jan
Several masonry trial wallets were prepared for the testing. The specimens were mounted into a special testing rig which enabled simultaneous uniform compression and cyclic horizontal loading on the top of the tested specimen. There were four hydraulic jacks generating the vertical load which was transmitted to the wall by eight ties and a steel 'hatö on the top of the wall. Horizontal displacement (force) on the top of the wall was introduced from servo-hydraulic MTS actuator of 250 kN capacity. Experimental part involved testing of brick walls for determination of crack pattern development under various combined loadings and testing of brick, sandstone and marly lime stone walls for crack and damage determination by application of NDT methods. Four approaches have been studied and evaluated: i) sonic wave propagation, ii) stress wave propagation, iii) crack pattern development, iv) modal analysis in which also a case study has been accompanied with a related pilot shaking table test of a one leaf masonry model.

National Repository of Grey Literature : 60 records found   beginprevious49 - 58next  jump to record:
See also: similar author names
41 VÁLEK, Jan
5 Válek, Jakub
2 Válek, Jaroslav
8 Válek, Jiří
5 Válek, Josef
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