Mortar Tests 24 months on St Astier Pure NHL
TESTS ON ST ASTIER PURE NHL MORTARS

Note: performance figures will vary using different sands.
For example see figures on NHL 3.5 tested using a 3mm - 0.075 well graded common sand (Doyeaux).

  1:2 1:2.5 1:3 Norm/method used for test
NHL 5 NHL 3.5 NHL 2 NHL 5 NHL 3.5 NHL 3.5 NHL 2 NHL 5 NHL 3.5 NHL 2
          Doyeaux sand          
Water content gr. 225 226 228 215 220 250 214 208 211 206  
Water/binder ratio 0.67 0.88 1.07 0.79 1.07 1.21 1.27 0.92 1.23 1.47  
Penetration mm 8 9.5 11 7.5 9 10 8.5 7 8.5 9.5 EN459-2 P.5.5.3
Set (beginning) h 4.3 5.3 8 3/4 3.3 6 6.15 9 3 6 9.3 EN196.2 P.6.2
Bulk density kg/m3
(no curing)
2110 2110 2100 2115 2140 1975 2080 2105 2110 2100 EN459.2 P.5.8
Air content % 0 1.6 2 0 0 0 1 0 3 2 EN459.2 P.5.7
Elast. Moduli Mpa                      
28 days 10800 9010 9025 11000 9000 8600 9800 10000 8970 9000 French Std
on one coat renders
6 months 18000 16250 12600 17050 13505 12050 12030 16900 12450 11800
12 months 18510 15280 12515 17280 13620   12030 16150 13150 11900  
24 months 21500 17480 13375 18020 13785   12000 17540 13670 11750  
Flexural Strength Mpa                   EN459.2
7 days 0.53 0.43 0.28 0.38 0.31 0.28 0.31 0.4 0.28 0.25  
28 days 0.9 0.73 0.74 0.8 0.48 0.45 0.73 0.66 0.65 0.72  
6 months 2.2 2.18 1.28 1.75 1.7 1.3 1.2 1.55 1.38 1.08  
12 months 2.4 2.25 1.3 2.2 2.05   1.25 1.8 1.5 1.05  
24 months 2.51 2.6 1.41 2.3 2   1.15 2.05 1.53 1.05  
Compressive Strength MPa                   EN459-2 P.5.1
7 days 1.96 0.75 0.62 1 0.57 0.5 0.53 0.88 0.53 0.47  
28 days 2.2 1.88 1.48 2 1.47 1.3 1.36 1.5 1.34 1.25  
6 months 7.31 7.1 3.84 5.91 5.34 4.02 3 5.31 3.94 2.88  
12 months 9.28 7.5 4 8.44 5.9   2.9 6.5 3.9 2.9  
24 months 10.81 8.63 4.25 8.81 6   3 7.8 3.97 2.75  
                Fr. Std. for
one coat renders
Permeability at compl. carb gr. of air/m2 x hour x mmHg 0.55 0.64 0.68 0.5 0.65   0.71 0.52 0.72 0.71
Shrinkage at 28 days mm.m 0.17 0.59 0.75 0.13 0.44   0.6 0.15 0.25 0.51  
Water absorption l/hxm 2 3 4.5 10.5 3.2 7.3   12.1 5.5 9.4 15.4 at compl. Carbonation
Capillarity gr/cm2 xmin1/2 0.88 1.18 3.05 2.54 4.7   7.84 4.61 6.3 8.7 at compl. Carbonation

NHL / Putty lime blends

NHL 5/Putty/Sand NHL 3.5/Putty/Sand Test Norm/method used
Blend ratio 0.9/0.1/3 0.7/0.3/3 0.5/0.5/3 0.9/0.1/3 0.7/0.3/3 0.5/0.5/3  
Water/binder ratio gr 1.2 1.07 1.03 1.04 1 0.95  
Penetration mm 7 10 11 8 12 13 EN459-2 P.5.5.3
Set (beginning) h 3.5 5.25 9.5 6.5 8.5 10 EN196-2 P.5.8
Bulk density kg/m3 (no curing) 2105 2040 2030 2070 2040 2020 EN459-2 P.5.8
Air content % 0 0 3 3 4 6 EN 459-2 P. 5.7
Elast. Moduli Mpa              
28 days 11000 10020 8000 8400 8050 7510 French Std
on one coat renders
6 months 16000 14000 13000 13200 12600 11000
12 months 16510 14320 13020 13410 12900 11050  
24 months 16500 13950 13220 14520 13010 10850  
Flexural Strength N/mm2              
7 days 0.4 0.35 0.32 0.38 0.5 0.26 AN459.2
28 days 0.67 0.65 0.45 0.6 0.52 0.38  
6 months 1.15 1.13 0.83 1.33 1.05 0.65  
12 months 1.75 1.15 0.85 1.5 1.2 0.8  
24 months 1.55 1.2 0.8 1.56 1.26 0.84  
Compressive Strength N/mm2              
7 days 0.82 0.66 0.42 0.76 0.76 0.22 EN459-2 P.5.1
28 days 1.4 1.1 0.6 1.3 1.1 0.75  
6 months 4.8 3.95 2.97 3.9 3.63 2  
12 months 5.3 4.1 2.8 4.8 4.4 3.75  
24 months 5.25 4.31 2.85 4.75 4.55 2.65  
             
Permeability at complete Carb
(vapour exchange) gr of air  x m2 x hour x mmHg
0.6 0.59 0.63 0.69 0.71 0.68 Fr. Std
on one coat renders
Shrinkage at 28 days mm/m 0.25 0.6 0.84 0.35 0.67 0.89
Water absorption l/hxm2 at compl. Carbonation 10 12.3 18 11.2 15.6 19.3  
Capillarity gr/cm2 xmin1/2at compl. Carbonation 4.41 8.72 12.94 9.95 10.2 13.75  

CEMENT / HYDRATED LIME / SAND

Blends 1:1:6 1:2:9 Norm/method used for test
Water content gr. 200 200  
Water/binder ratio 0.72 0.65  
Penetration mm 7 7 EN459-2 P.5.5.3
Set (beginning) h 1.3 1 EN459-2 P.6.2
Bulk density (no curing) kg/m3 2100 2100 EN459-2 P.5.8
Air content % 0 0 EN459-2 P.5.7
Elast. Moduli Mpa     French Std. for
one coat renders
28 days 16200 15595
6months 22010 19300 EN459-2
12 months 22210 19700  
24 months 22150 19650  
Flexural Strength N/mm2      
7 days 2.05 1.65  
28 days 1.95 1.55 EN459-2 P.5.1
6 months 2.1 1.5  
12 months 2.2 1.7  
24 months 2.2 1.75  
Compressive Strength N/mm2      
7 days 5.02 4.96  
28 days 7.7 5.56  
6 months 8.1 5.75  
12 months 8.7 6.05  
24 months 8.5 5.95  
Permeability (Vapour exch)
gr of air x m2 x hour x mmHg
0.23 0.25  
At complete carbonation
French Std. for
one coat renders
Shrinkage at 28 days mm/m 0.63 0.42
Water absorption l/hxm 2
at compl. Carbonation
0.23 0.25
Capillarity gr/cm2 xmin1/2 1.08 6.86  

St.Astier Mortar tests : 24 months results
September 2000

Enclosed the final results as follows:
Sheet 1 : Test on NHL/Sand mixes (1:2  1:2.5  1:3)
Sheet 2 : Tests on NHL/Putty /Sand blends (NHL blended with Putty@ 10%  30%  50%)
Sheet 3 : Test on Cement/lime/sand mixes (1:1:6  1:2:9)

NOTES:

Compressive strenght in NHL mortars is achieved gradually, allowing for movement.
This is due to the lack of cement. In cementitious mixes the hardening is much faster and mostly complete within 28 days.

Elasticity, which is so important to achieve joint free construction, is by far better in NHL mortars than cementitious mixes.

Shrinkage, capillarity and vapour exchange (permeability to air) also show better values than cementitious mixes.

The test on NHL/Putty blends shows the significant performance alteration that takes place Although this does not signify that these blends cannot be used, we think that the specifier should be aware of the related performance.

The initial set up of these test was done in consultation with:
Mrs. J. M. Teutonico of English Heritage, Mrs. P. Gibbons of The Scottish Lime Centre,
Prof. John Ashurst and Douglas Johnston to whom we are grateful for their co-operation and suggestions.

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For further Guidance, contact your St Astier Distributor.
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