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 . 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 flat jack is then loaded in the cut and the pressure is gradually increased by a hydraulic pump until the state of strain is equal to the previously existing condition before the cut.
Mike Schuller discusses the origins of the flat jack test. Edited by: Jimmy Kurzawa. This paper presents the of in situ flat – jack tests , i. In this paper, a state of the art about flat – jack testing is presented together with some experiments carried out by the author. 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 . 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 . It is a laboratory test to calculate the compressive strength of a masonry prism. The prism can be obtained from site or can be manufactured in lab as a representative modal of site. It used to check that whether the masonry is providing sufficient strength or not. Flat Jacks : Controls concrete testing equipment. Sisgeo supply a complete set for flat jack tests : flat jack pressure pa tubes and valves, pump, manometers and electrical pressure transducers.
Determination of the resistance and deformation under load Evaluation of the tensile stress Measurement of the elastic modulus and breaking load. 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 . 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.
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 . The information obtained include the measurements of large cavities and a general view of the materials. Luigia Binda, Claudia Tiraboschi D. Politeenico di Milano, Piazza L.
A long experience of application was developed by several . Printed in Great Britain. AN INVESTIGATION OF THE FLAT JACK METHOD OF. Australian National University, Canberra, Australia.