APPENDIX E: AIR-VOID ANALYSES
ASTM C 457, Modified Point Count Method
NCMA-SRW-A10
Cum. no. of points landing on
Cumulative
Volume fractions (%)
No. of inter-
Traverse
Fine
Cement
Total
total no.
Fine
Cement
Total
connected
no.
aggregate
paste
air
of points
aggregate
paste
air
air voids
1
27
26
6
59
45.8
44.1
10.2
27
2
53
42
22
117
45.3
35.9
18.8
49
3
85
57
35
177
48.0
32.2
19.8
71
4
113
77
46
236
47.9
32.6
19.5
91
5
147
94
54
295
49.8
31.9
18.3
114
6
177
117
61
355
49.9
33.0
17.2
132
7
212
134
69
415
51.1
32.3
16.6
146
8
245
151
77
473
51.8
31.9
16.3
162
9
279
167
88
534
52.2
31.3
16.5
178
10
314
185
98
597
52.6
31.0
16.4
202
Total length of traverse (T) = (Total no. of points No. of traverse lines) * Grid interval = 372.2 mm
Voids/mm = n = N/T = 0.54
Specific surface in mm2/mm3 = 4/l = 13.21
Average chord intercept (l) in mm = A/100 n = 0.30
Paste/air ratio (p/A) = 1.888 <4.342
If p/A >4.342, then spacing factor (L) = 226 m
If p/A <4.342, then spacing factor (L) = 143 m
Conclusion: Air content is high. Spacing factor is small (good). Most of the aggregate is quartzite, well graded,
and apparently sound. The air void system in the cement paste is good and aggregate is of good quality. Good
F-T resistance is expected.
NCMA-SRW-G1
Cum. no. of points landing on
Cumulative
Volume fractions (%)
No. of inter-
Traverse
Fine
Cement
Total
total no.
Fine
Cement
Total
connected
no.
aggregate
paste
air
of points
aggregate
paste
air
air voids
1
36
7
1
44
81.8
15.9
2.3
6
2
60
18
9
87
69.0
20.7
10.3
18
3
90
25
13
128
70.3
19.5
10.2
31
4
118
36
18
172
68.6
20.9
10.5
42
5
151
46
19
216
69.9
21.3
8.8
51
6
178
56
23
257
69.3
21.8
8.9
64
7
207
64
29
300
69.0
21.3
9.7
75
8
238
71
32
341
69.8
20.8
9.4
85
9
264
80
38
382
69.1
20.9
9.9
97
10
288
96
41
425
67.8
22.6
9.6
109
Total length of traverse (T) = (Total no. of points No. of traverse lines) * Grid interval = 263.5 mm
Voids/mm = n = N/T = 0.41
Specific surface in mm2/mm3 = 4/l = 17.15
Average chord intercept (l) in mm = A/100 n = 0.23
Paste/air ratio (p/A) = 2.341 <4.342
If p/A >4.342, then spacing factor (L) = 191 m
If p/A <4.342, then spacing factor (L) = 137 m
Conclusion: Air content is low. Spacing factor is low (good). Based on air voids in the paste alone, adequate F-
T resistance is expected. The aggregate appears to be sound, well graded, well packed, and angular. Paste/air
ratio is low.
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