Regular Concrete
Regular concrete is a versatile building material composed of portland cement, water, fine aggregate (sand), and coarse aggregate (gravel or crushed stone). It is the most widely used construction material in the world, valued for its durability, versatility, and relatively low cost.
Composition
Mixture of portland cement (10-15%), water (15-20%), fine aggregate/sand (25-30%), and coarse aggregate/gravel or crushed stone (40-50%). The cement and water form a paste that binds the aggregates together, hardening through a chemical process called hydration.
Properties
Compressive Strength
3,000-5,000 psi typical
Excellent resistance to compression forces, with strength increasing over time as curing continues.
Tensile Strength
300-500 psi typical
Approximately 10% of compressive strength, making reinforcement necessary for spanning applications.
Density
140-150 lbs/ft³
Relatively high density contributes to thermal mass and sound attenuation properties.
Thermal Properties
Good thermal mass
Stores and slowly releases heat, helping to moderate temperature fluctuations in buildings.
Fire Resistance
Excellent
Non-combustible and provides good fire protection for other materials.
Curing Time
28 days for full strength
Reaches approximately 70% of design strength in 7 days, but continues to gain strength for years.
Applications
Foundations and Footings
Forms the structural base for buildings, distributing loads to the soil and providing stability.
Slabs on Grade
Creates floor surfaces for residential, commercial, and industrial applications, providing a durable, level surface.
Driveways and Walkways
Provides durable, weather-resistant surfaces for pedestrian and vehicular traffic in exterior applications.
Retaining Walls
Holds back soil and prevents erosion on sloped sites, often with reinforcement for taller applications.
Simple Structural Elements
Forms basic structural components like short columns and low walls when reinforced appropriately.
Paving and Hardscaping
Creates patios, plazas, and other exterior surfaces, often with decorative finishes or patterns.
Advantages
- Relatively low cost compared to many building materials
- Versatility and adaptability to various forms and applications
- Excellent durability and longevity with minimal maintenance
- Fire resistance and non-combustibility
- Local availability in most regions, reducing transportation impacts
- Thermal mass properties that contribute to energy efficiency
- Ability to incorporate recycled materials in the mix
- Resistance to water, rot, and insect damage
Limitations
- Poor tensile strength requiring reinforcement for spanning applications
- Potential for cracking due to shrinkage and thermal movement
- Heavy weight requiring substantial structural support
- Porous nature potentially allowing moisture penetration without proper treatment
- Significant environmental impact from cement production
- Long curing time before achieving full strength
- Limited flexibility for modifications after installation
- Poor insulating properties requiring additional materials for thermal efficiency
Sustainability Profile
Moderate to low sustainability profile due to high carbon emissions from cement production, which accounts for approximately 8% of global CO₂ emissions. However, concrete's durability and thermal mass properties contribute to sustainability over its lifecycle. Sustainability can be improved through: (1) Incorporating supplementary cementitious materials like fly ash, slag, and silica fume to reduce cement content; (2) Using recycled concrete aggregate; (3) Optimizing mix designs to reduce cement content; (4) Capturing and sequestering carbon during curing; (5) Utilizing alternative, lower-carbon cements.