Concrete is strong, durable, and widely used across the world. However, it is not perfect. One of the most common problems seen in concrete structures is Temperature cracks. These cracks mainly develop due to temperature changes during and after construction. In desert construction, where temperatures can rise sharply during the day and fall suddenly at night, the risk becomes even higher.
This blog explains Temperature cracks in simple terms, how they form, why they are common in hot regions, and how their behaviour changes from one place to another.
What Are Temperature Cracks?
Temperature cracks are cracks that form in concrete due to expansion and contraction caused by temperature variations. When concrete heats up, it expands. When it cools down, it contracts. If this movement is restrained, stress develops, and cracks appear.
These cracks usually occur without any external load. They are different from structural cracks and mostly affect durability and appearance, although long-term neglect can reduce strength.
Why Temperature Cracks Occur in Concrete
Concrete is sensitive to temperature from the moment it is placed. Temperature cracks commonly occur due to the following reasons:
- High heat during cement hydration
- Rapid cooling after casting
- Large temperature difference between the concrete core and surface
- Sudden day–night temperature variation
- Restraint from foundations, walls, or reinforcement
In desert construction, the surface of concrete cools faster at night, while the inner core remains hot. This uneven cooling creates tensile stress, leading to Temperature cracks.
Temperature Cracks in Desert Construction
Desert regions face extreme weather conditions. Daytime temperatures may exceed 45°C, while nights can be relatively cool. Such conditions make Temperature cracks a serious concern.
Key desert-related factors include:
- High ambient temperature during pouring
- Faster evaporation of water
- Reduced setting time
- Thermal shock during night cooling
For example, a concrete slab cast at noon in a desert area may expand excessively. When the temperature drops after sunset, contraction begins rapidly, resulting in visible Temperature cracks.
Types of Temperature Cracks
Temperature cracks can appear in different forms depending on location and exposure:
- Plastic thermal cracks – Occur during early hours due to rapid surface cooling
- Early-age thermal cracks – Caused by heat of hydration
- Long-term thermal cracks – Due to seasonal temperature changes
In massive elements like raft foundations or thick retaining walls, Temperature cracks are more prominent.
How Temperature Cracks Differ from One Place to Another
The behaviour of Temperature cracks varies depending on climate, materials, and construction practices.
- Desert areas: High frequency due to extreme heat and rapid cooling
- Cold regions: Cracks develop due to freezing and thawing cycles
- Coastal areas: Temperature combined with moisture increases crack width
- Moderate climates: Fewer Temperature cracks due to stable temperatures
Thus, design and curing methods must change based on location.
Case Study: Industrial Floor in a Desert Zone
An industrial warehouse floor was constructed in a Middle Eastern desert region. Concrete was poured during daytime without temperature control. Within three days, visible Temperature cracks appeared across the slab.
Findings:
- Pouring temperature exceeded 40°C
- No curing compound was used
- No expansion joints were provided
Solution:
- Concrete pouring shifted to night hours
- Proper curing for 7 days
- Control joints added at regular intervals
After correction, future phases showed no Temperature cracks.
Standards and Codes Related to Temperature Cracks
Several international standards address Temperature cracks:
- IS 456:2000 – Limits temperature differential in mass concrete
- ACI 224R – Control of cracking in concrete structures
- BS EN 1992 (Eurocode 2) – Thermal effects and crack control
These standards recommend joint spacing, reinforcement detailing, and temperature monitoring.
Prevention and Control of Temperature Cracks
To reduce Temperature cracks, the following practices are recommended:
- Use low-heat cement
- Control pouring temperature
- Provide expansion and contraction joints
- Proper curing using water or curing compounds
- Avoid casting during peak daytime heat
- Use insulation or shading in desert construction
Good planning plays a major role in minimising Temperature cracks.
Practical Example
A concrete pavement in a desert highway project showed fewer Temperature cracks after adopting night concreting and saw-cut joints at 4 m spacing. This simple change improved durability significantly.
FAQs on Temperature Cracks
Q1: Are Temperature cracks structural?
No, Temperature cracks are usually non-structural but can affect durability if ignored.
Q2: Can Temperature cracks be repaired?
Yes, epoxy injection or surface sealing can repair minor Temperature cracks.
Q3: Are Temperature cracks avoidable in desert construction?
They can be controlled but not fully eliminated due to extreme temperatures.
Q4: Do Temperature cracks reduce strength?
Small Temperature cracks mainly affect appearance, but wider cracks may allow moisture ingress.
Q5: When do Temperature cracks usually appear?
Most Temperature cracks appear within the first few days after concreting.
Conclusion
Temperature cracks are a common issue in concrete, especially in desert construction. They develop due to thermal expansion and contraction caused by extreme temperature variations. Although they are often non-structural, proper understanding, planning, and execution are essential to control them. By following standards, adapting construction practices to local climates, and applying correct curing methods, Temperature cracks can be effectively minimised, ensuring long-lasting and durable concrete structures.