Page 11 - 2018 DIGITAL BROCHURE

Bonding of NATCEM cement-based concretes to steel reinforcement
(C.E.B.T.P. Test No. 3114.6.883 in accordance with RILEM recommendation RC6)
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Test using 20 mm dia. high tensile deformed bar (Fe500) :
Max. tensile 28-day comp. Bond strength Reference bond
force (kN) strength (MPa) (MPa) strength (MPa)*
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Cast concrete with a 600 kg/m NATCEM 120.2 38.8 19.1 14.8
cement factor
Cast reference concrete with a 400 kg/m 117.7 46.6 18.7 12.0
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O.P.C. CEM I 52.5 cement factor
* The reference bond strength is corrected to correspond with a 30 MPa compressive strength.
5 RILEM = Reunion Internationale des Laboratoires d’Essais de Recherche sur les Materiaux de Construction, octobre
1973. (International Meeting of Construction Materials Research Laboratories, October 1973).
Carbon Dioxide Penetration - C.E.B.T.P. Test
The principle underlying the accelerated carbon dioxide penetration test is to measure the depth of
carbonation on a failure surface. 4 x 4 x 16 cm prismatic mortar specimens were used. After storage for
28 days in a damp room (20°C - 99% R.H.), the mortar specimens were placed in a container enclosing a
controlled atmosphere comprising 70% CO at 20°C and 50% R.H. After 1-3-710-21-28-36 and 60 days, the
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specimens were broken under shear and measurements of carbonation were taken by spraying a water-
alcohol solution of phenolphtaline onto the failure surface. The depth of carbonation is the average of the
carbonated depths measured on all four sides of the specimen.

The depth of Depth of carbonation (mm)
carbonation Age (days) CEM II b 32.5 ref. mortar NATCEM mortar
for a NATCEM
cement-based 1 day 1 0
mortar (1/2) and 3 days 2 0 The rate of
a reference CEM 7 days 3 1 carbonation for the
II b 32.5 cement- 10 days 3.5 1 NATCEM cement-
based mortar (1/3) 21 days 3.5 1 based mortar is
are given in the thus very low and
following table: 28 days 5 1.5 the carbonation
36 days 8 1.5 appears to cease
60 days 14 1.5 after 1 month.

Bonding (“Pull Out”)
TESTED IN ACCORDANCE WITH NF P 18 821 STANDARDS : PULL OUT TESTS FOR HYDRAULIC BINDER-
BASED FIXING GROUTS. 7-day results for a vertical rod grouted in a block :
Deflection * of grouted rod under a
NATCEM : (sand/cement = 1/1, w/c = 0.33) Load at failure (kN)
45kN load w.r.t. concrete support
on a dry support 0.3 49.4
on a damp support 0.24 50.1
1 Deflection of the rod with respect to the surrounding concrete must be less than 0.5 mm to comply with the Standard

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