English
© 2001 PROCEQ SA
Settings
7
4.4.2
Select Curve
The compressive strength of the concrete
f
ck can be cal-
culated from the rebound value R by means of conver-
sion curves. There are 3 options available for calculating
the compressive strength of the concrete:
- No conversion
- Select 5 internal conversion curves, or
- Choose between 2 programmed PROCEQ standard
curves (
f
ck 7 days and
f
ck 14 to 56 days).
No Conversion
Select ”No Conversion”.
At the end of a measurement series, only the average of
the rebound values
in relation to the impact direction is
displayed.
The corresponding compressive strengths of the con-
crete can be taken from the conversion curves in Fig. 8.1
and Fig. 8.2 under ”Standard Conversion Curves”,
page 19 and page 20.
Internal Conversion Curves
Parameters a, b and c of the curve functions must first
be set in the sub-menu ”Set up curve”.
• Under line number 1 to 5, select the conversion curve.
Select PROCEQ Standard Curves
For the derivation of the PROCEQ Standard curves, refer
to ”Derivation of the PROCEQ Standard Conversion
Curves”, page 19.
• Select conversion curve A in line no. 7 for concrete
with an age of 7 days (
f
ck7) or the conversion curve in
line no. 28 for concrete with an age of 14 - 56 days
(
f
ck28).
4.4.3
Set up Curve
The curve no. (1 to 5) and the parameters a, b and c
(see under ”Creating New Conversion Curve”, page 20)
can be set using the arrow keys.
4.5
Corrections
4.5.1
Shape Coefficient
α
s
The PROCEQ standard curves
f
ck7 and
f
ck28 are valid
for sample cubes with a 200 mm side for EPROM
versions up to 1.3 or from a 150 mm side from EPROM
version 2.0. If test specimens with different dimensions
are used for determining the compressive strength in the
pressure testing machine, the shape coefficient in the
first line is to be set or selected in line 2 to 4.
Shape of the test specimen:
1. Line: ”variable”, see Table 4.1
Tab. 4.1
Shape coefficients
Test specimen
Shape coeffi-
cients
EPROM version up to 1.3 from 2.0
Cube 300 mm and cylinder Ø 100x100 mm
0,90
0,85
Drill core Ø 100x100 mm
1,07
1,02
Drill core Ø 50x56 mm
1,09
1,04
Bedienungsanleitung DIGI-SCHMIDT 2000.qxd 12.12.2002 16:24 Seite E7
