| Feature | Thermal Stress Crack | Load-Induced Crack | Shrinkage Crack (Concrete) | |---------|----------------------|--------------------|-----------------------------| | | Often perpendicular to temperature gradient | Aligned with principal tensile stress | Random or map-patterned | | Width | Uniform or tapering, can be wide | Varies with load | Usually fine, uniform | | Timing | Appears during or just after temperature change | Under service load | Early age (plastic or drying) | | Surface | May show discoloration (oxidation) if hot crack | Clean or with debris | Dry, powdery edges possible |
Mass concrete dams are highly susceptible. Hydration of cement generates heat in the core, while the surface remains cooler. This produces: thermal stress crack
Thermal stress cracks are not random failures; they follow predictable mechanics of temperature gradients and material constraints. Understanding the interplay between heating/cooling rates, material properties, and geometric design is essential for engineers and manufacturers. With proper material selection, controlled thermal processing, and stress-relief techniques, most thermal cracking can be prevented. | Feature | Thermal Stress Crack | Load-Induced
An alternative approach to create significant thermal shock-induced damage involves heating rocks to elevated temperatures and the... ScienceDirect.com Early age concrete thermal stress measurement and modeling Abstract. A large amount of heat can be liberated during cement hydration, causing very large temperature increases in mass concre... The University of Texas at Austin Show all Material Primary Causes Typical Failure Patterns Glass Partial shading, sudden temperature swings, or high-absorbency tints. Perpendicular cracks starting from the edge and spreading toward the center. Concrete Heat of hydration in mass concrete (dams, bridge piers) or cooling phases. Internal cracks that may propagate to the surface; often occurs within days of placement. Rocks Extreme environments, rapid cooling (liquid nitrogen, water spray). Orthogonal and polygonal fracture patterns; significant reduction in elastic modulus and strength. Coatings Mismatch in coefficients of thermal expansion (CTE) between coating and substrate. Mode I (opening) cracks driven by axial stress at the crack tip. Risk Factors & Resistance A material's ability to resist thermal shock (Thermal Shock Resistance) is generally determined by: High Thermal Conductivity ScienceDirect