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FLAT JACKS – TESTS ON BRICKWORKS

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DETERMINATION OF RESISTANCE AND DEFORMATION UNDER LOAD
EVALUATION OF TENSILE STRESS
MEASUREMENT OF ELASTIC MODULUS AND BREAKING LOAD
The complete test is developed in two steps:
DETERMINATION OF 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 mortar layer, and it is measured the variation
of the two datum points.
The flat jack must be introduced, it is pressurized in different growing phases and the variation between the datum points is measured, by
determining the static load.
DETERMINATION OF DEFORMATION AND RESISTANCE (IN-SITU STRESS)
Two flat jacks are used.
It must be done a second cut, parallel to the first one, level with the mortar layer, having a distance of approximately 50 cm from the first cut.
Another flat jack must be introduced.
Three couples of datum points are placed on the brickwork portion between the two cuts.
Start to pressurize the two flat jacks at growing phases.
The variation of distances of the datum points at different pressure steps allows to delineate a strength-deformation curve, obtaining elastic
modulus, Poisson and breaking point values.

C358-01
RECTANGULAR FLAT JACK high deformability, max. pressure
50 bar, dimensions 400x200x4 mm. Steel sheet 0.8 mm thick
Complete with nuts and groins.

C358-11
N° 6 STEEL SHEETS, dimensions 400×200 mm, three pieces 1 mm
thick, three pieces 1.5 mm thick

C358-02
SEMI-OVAL FLAT JACK ad high deformability, max. pressure 50 bar,
dimensions 350x260x4 mm. Steel sheet 0.8 mm thick.
Complete with nuts and groins.

C358-12
N° 6 STEEL SHEETS, dimensions 350×260 mm, three pieces 1 mm
thick, three pieces 1.5 mm thick.

C358-05
STOPCOCK (valve) high pressure complete with fittings, to close the
oil flow in the jack and stop the pressure.
LOAD APPLICATION
C358-06 HYDRAULIC HAND PUMP, complete with integral reservoir
with oil, to apply pressure to the jacks.
C358-15 Flexible rubber TUBE, 3 meters length, for the connection
to one jack.
or:
C358-16 Flexible rubber DOUBLE TUBE, 2 and 3 meters length,
for the connection to two jacks.
C358-08 MANOMETER high precision 0 – 60 bar range, with
fast jack, to be fixed on the pump to read the applied
pressure.

STRAIN MEASUREMENT
C361 KIT STRAIN GAUGE-EXTENSOMETER with mechanical strain
gauge, 300 mm length
or:
C363 KIT STRAIN GAUGE-EXTENSOMETER with digital strain
gauge, 300 mm length
Other strain gauge models with accessories described in detail at
p. 359

As alternative to the strain gauge, the data acquisition and
processing system can be used, with the following equipment:
C358-21
ELECTRONIC EXTENSOMETER, supplied with linear displacement
transducer having 10 mm stroke and 0.1% linearity, fitted in a
tubular anodized aluminum frame, complete with electrical cable and connector .

Span: 300 mm
Weight: 300 g approx.

C358-23N
PRESSURE TRANSDUCER, 50 bar capacity, to be fitted to the hand
pump (as alternative to the manometer).
Complete with fast jack to the pump, electrical cable and connector.
C405-15N
CYBER-PLUS 8 EVOLUTION TOUCH SCREEN
8 Channels acquisition and processing data system, 24 bit resolution.
Electronic advanced technology, colour touch screen 1/4VGA,
high graphic performances, the unit automatically performs test
and data processing. A certificate can be printed through a printer
(optional) directly connected to the unit through the USB port.
The Cyber-Plus is equipped with slots for external pendrive or SD
card infinite memory supports, it can be directly connected to a PC.
Contained in a practical and sturdy watertight carrying case, can be
powered from an electrical network 90-270 V or use the internal
battery and charger granting one full day on-site use.
Hardware technical details: see p. 18
S337-51
CALIBRATION process between the electronic extensometer or the
pressure transducer to the data acquisition unit C405-15N