1. What is Resilient Modulus?

Resilient Modulus (M_r) is a measure of material stiffness that represents the ratio of applied stress to recoverable strain in materials subjected to repeated loading. It is commonly used in pavement engineering to characterize the elastic behavior of soils and aggregates under cyclic loading conditions.

2. How Does the Calculator Work?

The calculator uses the fundamental resilient modulus equation:

Where:

• \( M_r \) — Resilient modulus (Pa)
• \( \sigma \) — Applied stress (Pa)
• \( \varepsilon \) — Recoverable strain (unitless)

Explanation: The equation calculates the material's ability to recover elastically after repeated loading, which is crucial for pavement design and analysis.

3. Importance of Resilient Modulus Calculation

Details: Accurate resilient modulus determination is essential for pavement design, predicting material performance under traffic loads, and ensuring long-term structural integrity of transportation infrastructure.

4. Using the Calculator

Tips: Enter stress in Pascals (Pa) and strain as a unitless value. Both values must be positive numbers greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range of resilient modulus values?
A: Resilient modulus values vary widely depending on material type, ranging from 20-50 MPa for subgrade soils to 200-400 MPa for base course materials.

Q2: How does resilient modulus differ from Young's modulus?
A: While both measure stiffness, resilient modulus specifically addresses recoverable deformation under repeated loading, making it more suitable for pavement materials subjected to traffic loads.

Q3: What factors affect resilient modulus?
A: Key factors include material type, moisture content, density, stress level, loading frequency, and number of load repetitions.

Q4: When is resilient modulus testing required?
A: It's essential for mechanistic-empirical pavement design, performance prediction, and quality control in road construction projects.

Q5: Can this calculator be used for all materials?
A: This basic calculator provides fundamental calculation, but specialized testing may be needed for complex material behavior under different stress conditions.