High Pavement Temperature and Anchor Capacity
Asphalt becomes less stiff as it heats, which can reduce the pull capacity of an installed anchor. Our testing shows a clear temperature effect, but the result depends on the asphalt mixture and site conditions.
Temperature matters in two different ways:
| Question | Relevant temperature |
|---|---|
| Can I install the anchor? | Ambient, adhesive, and pavement temperature during installation |
| How much can a cured anchor hold? | Pavement temperature while the anchor is under load |
This page covers the second question. For adhesive handling and installation limits, see Weather and Temperature Installation.
What We Measured
Section titled “What We Measured”On this page, measured pull capacity means the peak pull force recorded during a short-duration vertical pull test. It is a test result, separate from the guide load.
Our temperature measurements are grouped into 10°F buckets. For each anchor model, we use its average peak pull force in the bucket labeled 70°F as the 100% reference, then normalize results in the higher-temperature buckets to that reference.
The 120°F bucket is the highest pavement temperature tested so far. Each anchor model’s average peak pull force in that bucket fell between 58% and 62% of its corresponding 70°F reference average.
| Pavement-temperature bucket | Average peak pull force relative to reference | Status |
|---|---|---|
| 70°F | 100% | Reference average for each anchor model |
| 120°F | 58–62% | Measured range across tested anchor models |
Bucket labels represent grouped temperature measurements; they do not mean that every test occurred at exactly the labeled temperature.
SP10 Example
Section titled “SP10 Example”The SP10 had an average peak pull force of 2,351 lb in the 70°F reference bucket. Applying the measured cross-model retention range of 58–62% for illustration corresponds to approximately 1,364–1,458 lb. This is an illustration using the cross-model range, not a separately reported range of SP10 test results.
Averages hide the weaker installations. The SP10’s 900 lb pull guide load is set from the low end of our results, not the average, so that it stays below the low end of our 120°F results. An individual installation may still perform differently, so do not treat the normalized percentage as a universal design factor.
How to Interpret the Results
Section titled “How to Interpret the Results”- The percentages are relative to each anchor model’s own average peak pull force at 70°F, not to its guide load.
- The 58–62% range describes measured average retention across the anchor models tested at 120°F. It is not the spread of individual test results or a guaranteed minimum.
- The measurements do not establish a smooth correction curve between temperature buckets.
- Do not extrapolate the result above 120°F; higher pavement temperatures have not yet been tested.
For the test setup, see Pull Test Methodology.
Why Results Vary by Pavement
Section titled “Why Results Vary by Pavement”Asphalt temperature is only one part of the result. Binder grade and modification, recycled asphalt content, aggregate structure, air voids, pavement age, condition, load duration, and the temperature through the anchor’s embedment depth can all affect performance.
Our current measurements come from professionally installed, approximately one-year-old PG64-16 asphalt in Sonoma County. They establish a reference for that pavement, not a universal temperature correction for all asphalt mixtures.
A pavement’s binder grade is also not the same as a momentary surface-temperature reading. An anchor interacts with asphalt across its embedment depth and experiences a temperature gradient. A surface infrared measurement is useful for field screening, but it does not fully describe the temperature of the asphalt supporting the anchor.
How to Use This Information
Section titled “How to Use This Information”- At or within the tested range: Treat the measured retention as test evidence for the Sonoma pavement, not as a guaranteed capacity for another site.
- Above the tested range: Do not extrapolate beyond the 120°F bucket.
- Unknown pavement: Do not infer an exact binder grade or anchor capacity from location alone.
- Critical application: Obtain available pavement mix information and perform on-site pull testing under representative temperature and loading conditions.