Joint Sealants are commonly used to protect and seal Portland Cement Concrete (PCC) pavement joints. Under this NTPEP evaluation program, both hot-poured and cold-applied joint sealants materials are field tested for three years and laboratory tested according to a variety of ASTM specified test methods.Moisture is a key ingredient to the development of many durability-related distress types. As a result, these distress types are often observed to be much more severe at joints and cracks, where moisture can penetrate the concrete from several surfaces. Sealing joints and cracks can help reduce the amount of infiltrated water. However, the effectiveness of sealing depends on several issues:
It is impossible to completely eliminate the intrusion of moisture at joints and cracks, especially for an extended period of time. A Minnesota study found that the amount of infiltrated water (measured using tipping buckets at drainage outlets) returned to the same levels within 2 weeks after resealing (Hagen and Cochran 1995). This confirms that moisture can continue to penetrate the concrete at joints and at other locations, making this approach a short-term solution under the best of circumstances. are widely usedipe is intended for surface and subsurface drainage applications where soil provides suport to its flexible walls. Its major use is to collect or convey drainage water by open gravity flow, as culverts, storm drains, etc.
AASHTO is pleased to announce launch of a coordinated evaluation of Crack Sealers for HMA pavements under the auspices of its National Transportation Product Evaluation Program (NTPEP).
Crack Sealers are commonly used to protect and seal Hot Mix Asphalt (HMA) pavement cracks from moisture and other deleterious material. Under this NTPEP evaluation program the sealers are field tested for three years and laboratory tested according to a variety of ASTM specified test methods.
The NTPEP Technical Committee responsible for authoring the Project Work Plan for both Joint Sealants and Crack Sealers convenes yearly at the NTPEP National (Annual) Meeting. During this working meeting, the Project Work Plan is discussed, changes made, and shortly thereafter balloted for adoption. Improvements are immediately implemented in the next available testing cycle. The work plan can be found by clicking on "Documents" in the right side menu. When compared to other standards development exercises, the NTPEP process is agile, effective and efficient.
NTPEP Designated Labs: