Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D41 – Standard Test Method Technical Guide
ASTM D41/D41M – 11 (Reapproved 2023), also designated as AASHTO No. M116, establishes the standard specification for asphalt primer used in roofing, dampproofing, and waterproofing applications. This specification covers asphaltic primers suitable for application to concrete, masonry, metal, and asphalt surfaces both below and above ground level.
📐 Standard Classification and Primer Types
The standard classifies asphalt primers into two primary types based on their solvent-to-asphalt ratio:
- Type I is characterized by a generally higher solvent-to-asphalt ratio, resulting in a lower viscosity range suitable for specific substrates and application conditions.
- Type II is characterized by a lesser solvent-to-asphalt ratio than Type I, providing a higher viscosity for specialized application methods and environmental conditions.
⚙️ Physical and Performance Requirements
All primers must comply with strict limits regarding water content, viscosity, and distillation performance. The residue obtained from the distillation up to 360 °C [680 °F] must also meet specific penetration and solubility criteria to ensure proper performance in the field.
| 🟦 Requirement | 📏 Type I | 📐 Type II | 🎯 Test Method |
|---|---|---|---|
| Water, Vol %, max | 0.5 | 0.5 | D6511 |
| Saybolt Furol Viscosity at 25 °C [77 °F] | 25 to 125 s | 120 to 500 s | D88/D88M |
| Distillation up to 225 °C [437 °F], Vol % | not less than 35 | not less than 30 | D402/D402M |
| Distillation up to 360 °C [680 °F], Vol % | not more than 65 | not more than 60 | D402/D402M |
💡 Critical Quality Indicators: The residue from the distillation up to 360 °C [680 °F] must have a penetration of 20 to 50 dmm at 25 °C [77 °F] and a solubility in trichloroethylene of not less than 99 %. These properties ensure adequate adhesion and waterproofing characteristics.
📋 Sampling Procedures
To ensure a representative sample for conformance testing, a systematic random selection process is required. The number of packages selected from a shipment must be equivalent to the cube root of the total number of packages in the lot, rounded up to the next whole number. The following table provides a convenient reference for typical shipment sizes.
| 📦 Packages in Shipment | ⚡ Packages Selected |
|---|---|
| 2 to 8 | 2 |
| 9 to 27 | 3 |
| 28 to 64 | 4 |
⚠️ Safety Advisory: Per Section 1.3 of the standard, it is the responsibility of the user to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to using this primer. Solvent-based primers are flammable and require proper ventilation.
❓ Frequently Asked Questions
🔍 What is the primary difference between Type I and Type II primers?
Type I has a higher solvent-to-asphalt ratio, resulting in a lower Saybolt Furol viscosity (25 to 125 s) compared to Type II (120 to 500 s) at standard test temperature.
💡 On what surfaces can ASTM D41 primer be applied?
The specification covers primers for application to concrete, masonry, metal, and asphalt surfaces in roofing, dampproofing, and waterproofing contexts.
⚡ What are the critical performance requirements for the distillation residue?
After distillation up to 360 °C, the residue must exhibit a penetration of 20 to 50 dmm and a minimum solubility of 99 % in trichloroethylene to ensure proper binding and waterproofing.
📌 How is the sampling size determined for a specific shipment?
The sampling size is the cube root of the total number of packages in the lot, rounded up to the next whole number. For example, a shipment of 15 packages requires 3 samples.