The cores selected for air void analysis are given in Table 1 along with their conditions based upon visual observations. Table 2 presents results of the air void analysis. Trends in total air and air void spacing as both original and effective values are plotted versus core depth and will be presented in the petrography section (section 3.2). Examination of these plots, as well as a plot of concrete component distribution proved helpful in understanding the deterioration of the pavements.
| Table 1. Cores Selected for Linear Traverse Analysis: C 457, Modified Point Count | |||
|---|---|---|---|
| Core # | Road | Location | Condition, comments |
| 2 | Iowa 175 | J | Test section, 15 % Class C fly ash, appears sound |
| 11 | I-35, Story | J | No vibrator trail evident, North-bound lane, |
| 12 | I-35, Story | M | Pattern cracking at mid-panel joints |
| 7 | US 20 | JB | Mix 3, severe pattern and longitudinal cracking |
| 8 | US 20 | MB | slight transverse cracking, joint spalling, popouts |
| 13 | US 20 | JB | Mix 2, appears sound |
| 14 | US 20 | MB | |
| 18 | US 20 | JB | Mix 1, sound in this location |
| 19 | US 20 | J | Mix 1, severe map cracking, cracking along joints, |
| Paved over before site visit | |||
| 29 | I-80 | MO | Longitudinal and slight pattern cracking |
| J = joint M = midpanel B = between vibrator trail O = on vibrator trail | |||
| Specimens without a vibration trail code reflect the lack of a clearly discernable vibration trail at that location. | |||
| Table 2. ASTM C-457 Modified Point Count Results of Original and Effective Entrained Air Void Parameters. | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Air Content | Volume Percent | Paste/Air Ratio | Specific Surface (mm-1) | Spacing Factor (mm) | ||||||
| Core | Orginal* | Effective | Paste | Aggregate | Org. | Eff. | Org. | Eff. | Org. | Eff. |
| 2 | 11.9 | 11.7 | 21.2 | 66.9 | 1.8 | 1.8 | 17.5 | 17.1 | 0.10 | 0.11 |
| ± 1.7 | ± 1.6 | ± 2.1 | ± 2.7 | ± 2.6 | ± 2.6 | ± .01 | ± .02 | |||
| 11 | 8.0 | 6.0 | 27.0 | 65.4 | 3.4 | 4.5 | 21.3 | 15.2 | 0.16 | 0.30 |
| ± 1.7 | ± 1.4 | ± 2.4 | ± 2.6 | ± 3.8 | ± 3.3 | ± .03 | ± .06 | |||
| 12 | 8.6 | 7.9 | 21.4 | 67.3 | 2.5 | 2.7 | 17.4 | 10.1 | 0.18 | 0.34 |
| ± 1.4 | ± 1.3 | ± 2.1 | ± 2.0 | ± 3.1 | ± 2.0 | ± .03 | ± .06 | |||
| 7 | 6.0 | 4.3 | 28.8 | 65.2 | 4.8 | 4.5 | 29.1 | 9.0 | 0.16 | 0.74 |
| ± 1.0 | ± 0.9 | ± 2.0 | ± 2.0 | ± 4.9 | ± 1.9 | ± .03 | ± .16 | |||
| 8 | 5.9 | 4.6 | 25.3 | 68.9 | 4.3 | 5.5 | 35.4 | 21.1 | 0.12 | 0.26 |
| ± 1.2 | ± 1.1 | ± 2.3 | ± 2.1 | ± 7.4 | ± 5.3 | ± .03 | ± .06 | |||
| 13 | 6.6 | 6.2 | 25.6 | 67.9 | 3.9 | 4.1 | 22.1 | 18.4 | 0.18 | 0.22 |
| ± 0.9 | ± 1.2 | ± 2.3 | ± 2.7 | ± 4.6 | ± 3.9 | ± .04 | ± .05 | |||
| 14 | 6.5 | 6.3 | 25.0 | 68.2 | 3.8 | 3.9 | 18.1 | 17.3 | 0.21 | 0.23 |
| ± 1.2 | ± 1.3 | ± 2.3 | ± 2.7 | ± 3.8 | ± 3.8 | ± .04 | ± .05 | |||
| 18 | 12.2 | 12.0 | 21.1 | 67.6 | 1.7 | 1.8 | 20.8 | 18.5 | 0.08 | 0.09 |
| ± 1.7 | ± 1.8 | ± 2.1 | ± 2.7 | ± 3.1 | ± 2.8 | ± .01 | ± .01 | |||
| 19 | 9.5 | 7.9 | 17.8 | 72.0 | 1.9 | 2.3 | 14.6 | 7.7 | 0.13 | 0.29 |
| ± 1.5 | ± 1.4 | ± 2.0 | ± 2.2 | ± 2.6 | ± 1.5 | ± .02 | ± .06 | |||
| 29 | 6.2 | 6.2 | 32.2 | 61.2 | 5.2 | 5.2 | 15.4 | 14.3 | 0.34 | 0.36 |
| ± 1.2 | ± 1.2 | ± 2.3 | ± 2.4 | ± 3.4 | ± 3.1 | ± .07 | ± .08 | |||