This technique was initially created for testing rocky terrain, having been exported to the evaluation of the stress state and mechanical behaviour of masonry structures. This technique is considered moderately destructive and has two setup outlines: using one (simple) or two (double) flat-jacks. The simple flat – jack test allows . Mike Schuller discusses the origins of the flat jack test.
Edited by: Jimmy Kurzawa.
The tests were carried out on load bearing masonry walls of an 18th century building located in the historical centre of Lisbon taking advantage of the flat-jack method. These in situ tests aimed the evaluation of the rubble stone masonry deformability properties in compression (double flat – jack test ) and the shear strength. The testing technique is based on the release of the stress in a small area of a structure by a plane cut perpendicular to its surface. The reIiability of the test , whi ch is based on the use of special flat – jacks , has been studied by means of cal ibration tests carried out at. Flat Jacks : Controls concrete testing equipment.
This paper presents the of in situ flat – jack tests , i. It is a minor destructive test used to assess the in situ mechanical properties of masonry under vertical loads.
It is based on the use of a hydraulic jack made of light-gauge metal welded into a flat rectangular or semicircular shape that expands under hydraulic pressure. The test requires only the removal of a portion of mortar . SYNOPSIS Large flat jack tests are used to assess rock mass deformability in the design stages of large projects. The paper introduces a methodology for interpretation of the tests, with which it is also possible to obtain the in situ normal and she.
Structural Engineering. Politecnico of Milano. Leonardo da Vinci, 32.
A long experience of application was developed by several . In this paper, a state of the art about flat – jack testing is presented together with some experiments carried out by the author. The complete test is developed in two steps: DETERMINATION OF THE STATIC LOAD (TENSILE STATUS) One flat jack is used. Two datum points are fixed across a mortar joint and the distance between the points is measured.
Successively a horizontal cut is carried out with the suitable tool (drill, cutting saw ) level with the . Laboratory studies were carried out to assess the reliability of the flat jack technique for the determination of existing stress in masonry structures. Experiments were carried out on two masonry specimens to evaluate the existing stresses using flat jack technique. In this paper an experimental-numerical metho centred on flat – jack tests , is presented for the identification of local stress states and possibly deteriorated elastic properties of concrete in existing dams. The flat jack used for the test was calibrated before the actual .
It is shown herein that the synergistic combination of new pattern of flat-jack experiment, computer simulation of the test . Flat – jack testing is a versatile and powerful technique that provides significant information on the mechanical properties of historical constructions. In particular, ASTM and RILEM standards are . Analytical studies have been done in support of the experimental. Sachhi- Landriani et.
They found their numerical models to be generally in support of experimental evidence, and offered . Sep Single and double flat – jack tests are presently used widely for assessing the mechanical characteristics of stone masonry. This technique remains as one of the most versatile in situ test procedure for the estimation of the main mechanical properties of masonry walls. Nevertheless their application is still . This method was used in several large dam sites in Portugal and some other countries. The flat – jack method belongs to the minor-destructive tests (MDT).
The paper presents the methodology of in-situ testing based on the flat – jack device. Beside NDT, MDT are recommended for historical buildings. Tests were carried out using .