A Guide to HVAC Units for the Amateur

When our family first moved into our home five years ago, the central heating and air unit were brand new. We never considered that there would be a time when it would not be operating as we wanted it to. When the time to buy a new unit came, we found that the available options were more diverse than we thought. It was all too confusing. After researching the different options, I decided to create this blog. My hope is that others who are faced with this decision can find easy-to-understand information that can aid in quickly making an informed decision.

Should Road Construction Crews Stop Paving In Certain Weather Conditions?

Construction & Contractors Blog

Most road construction projects are on a tight schedule and must be completed as quickly as possible so that normal traffic patterns can resume and the inconvenience to travelers is minimized. At the same time, inclement weather and less-than-ideal temperatures can prevent paving crews from safely and properly finishing their work. Under what weather conditions can paving continue, and when should it be halted?

Paving Under Rainy Conditions

It can be challenging for paving crews to determine just what constitutes too much rain to continue work. Some light precipitation may not impact operations to the point of shut down, but steady rain can certainly cause problems with asphalt application and other paving work. 

On the other hand, trucks that already have an asphalt mix prepared and are en route to the job site will waste what's been mixed if it is not applied within a time frame of a couple hours, depending on temperature and the exact mix of the asphalt material. 

Risks of applying asphalt in the rain include:

  • Puddles can form that can't be properly paved over. The water will evaporate, leaving air pockets between the aggregate and the asphalt that will cause instability in the finished road. If standing water is present, the paving job should be temporarily halted; water can be removed and the road base reworked to prevent puddles after the rain has passed.
  • Asphalt lifts won't bond together properly. The applied layers of material, called lifts, must be able to form a bond. If there is moisture between the layers, that bond will be compromised and the quality and durability of the road structure will suffer.
  • Cool, wet conditions can affect the asphalt mix. Rain is generally cool and can lower the temperature of the asphalt mix as it is being applied. If the mix cools too much before it is properly applied, it can be harder for road construction crews to compact or tamp down properly. This means air pockets are more likely and the finished pavement will be less durable over time.

Contractors may be able to pave some surfaces in mild inclement weather if that surface has been prepared properly and drains well. Applying asphalt to a stable base with a crushed aggregate that can drain away moisture may be possible even in light, steady rain. On the other hand, applying even a thin layer of asphalt as an overlay may cause problems. 

Paving in Cooler Temperatures

It's very possible to apply asphalt in cooler temperatures, but care must be taken to ensure that the asphalt mix does not get too cool. If the mix isn't hot enough, you might see the following issues:

  • Asphalt mix may become more viscous; in other words, it will be harder to pour and work with. You may have to compensate by increasing the temperature of the mix prior to pouring and working quickly with the applied materials.
  • Compacting must be finished more quickly. Compacting must be done before the asphalt mix drops below 185 degrees F, so it may need to be applied a little warmer than usual. Crews may need to apply mix in smaller sections and compact before continuing. If temperatures are extremely cold, paving may have to wait until the mercury rises a bit.

When in doubt because of weather conditions, road construction crews should wait -- even if it causes continued temporary delays, otherwise the integrity of the road surface could be compromised. For more information, contact companies like Lien Transportation Co.

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1 September 2016