Sustainable Concrete Solutions for the MENA Region

Ultra-Low Carbon, High-Durability Concrete for Coastal and Arid Climates

Project Title: Al Khaleej Towers – A Model for Sustainable High-Rise Construction in the MENA Region

1. Introduction

The Middle East and North Africa (MENA) region faces significant construction challenges due to high urbanization rates, extreme climate conditions, and resource scarcity. The cement and concrete industry is a major contributor to global CO? emissions, with concrete demand increasing by 6% annually in the region.

Dubai’s coastal environment presents additional durability concerns, such as high salinity, humidity, and extreme heat, accelerating structural degradation and material fatigue.

This study explores ultra-low carbon, high-durability concrete as a sustainable alternative for infrastructure resilience while reducing environmental impact and lifecycle costs. The 50-story Al Khaleej Towers project in Dubai serves as a model for green construction using a 70% Ground Granulated Blast Furnace Slag (GGBFS) + 30% Ordinary Portland Cement (OPC) blend, enhanced with micro silica.

This innovative concrete mix reduces CO? emissions by 40%, enhances durability against chloride ingress, and aligns with Dubai Municipality’s Green Building Regulations and COP28 climate goals.

2. Why Sustainable Concrete is Essential in the MENA Region

A. High Carbon Footprint of Conventional Concrete

• Concrete production accounts for 8% of global CO? emissions, primarily due to the energy-intensive clinker production in OPC-based concrete.
• MENA’s cement industry (Saudi Arabia, UAE, Egypt, Algeria, and Iran) produces millions of tonnes of CO? annually.
• Transitioning to low-clinker concrete (GGBFS, RCA, fly ash) can reduce carbon emissions by 40-50%.

B. Harsh Climatic Conditions: Extreme Heat & Water Scarcity

• Temperatures >45°C accelerate hydration, increasing thermal cracking risks in conventional concrete.
• The MENA region is one of the driest areas in the world, requiring water-efficient construction methods.
• Sustainable concrete reduces water demand by 20-30% using self-curing agents, RCA, and optimized mix designs.

C. Durability Challenges: Coastal & Marine Environments

• Over 60% of MENA’s population lives in coastal cities, where chloride ingress and sulfate attack accelerate concrete degradation.
• Sulfate-resistant GGBFS-based concrete extends structural lifespans to 75-100 years with lower maintenance costs.

D. Economic and Regulatory Benefits

• Green Building Incentives in UAE, Saudi Arabia, and Egypt encourage sustainable materials.
• Dubai’s Al Sa’fat Green Building Rating System provides 20% rebates for green construction.
• Lower lifecycle costs (30-40% maintenance savings) make sustainable concrete cost-effective.

3. Sustainable Concrete Strategy

A. Cementitious System

? 70% GGBFS (S95 grade) – Reduces clinker demand by 430 kg/m3. ? 30% OPC (CEM I, BS EN 197-1 compliant) – Ensures early strength development. ? 5% Micro Silica (SiO? ≥ 92%) – Enhances chloride resistance and pore structure refinement.

B. Aggregate Optimization

? 40% Recycled Concrete Aggregates (RCA) – Reduces natural resource depletion. ? Local Crushed Limestone – Lower porosity minimizes water absorption. ? Desalinated Dune Sand – Electrostatically separated to reduce chloride content.

C. Advanced Admixtures

? PCE Superplasticizer – Maintains high workability (180 mm slump) with low w/c (0.38). ? Shrinkage-Reducing Admixture (SRA) – Controls plastic shrinkage under desert winds. ? Corrosion Inhibitor (Calcium Nitrite) – Enhances reinforcement durability in marine environments.

D. Climate-Adapted Production & Curing

? Nighttime Batching – Reduces mixing temperatures from 42°C to 28°C. ? Flake Ice Replacement – Controls concrete temperature <25°C. ? Silane-Based Curing Compound – Seals surface moisture for durability.

4. Environmental Benefits of Sustainable Concrete

A. Carbon Footprint Reduction

? Embodied CO?: 220 kg/m3 vs. 380 kg/m3 (conventional concrete). ? Total project savings: 12,000 tonnes CO? (~removing 3,000 cars from roads annually).

B. Circular Economy & Waste Management

? Use of Industrial Byproducts (GGBFS, RCA, micro silica) reduces waste disposal. ? Recycled Aggregates minimize quarrying impacts.

C. Reduced Water Consumption

? Optimized mix design cuts water demand by 20-30%. ? Self-curing admixtures reduce additional water needs.

5. Performance Validation

A. Mechanical & Durability Testing

? Compressive Strength:

• 7 days: 22 MPa (formwork removal requirement).
• 28 days: 45 MPa (exceeds 40 MPa design target).
• 90 days: 58 MPa (GGBFS latent hydration properties).

? Durability Metrics:

• Chloride Migration Coefficient: 3.2 ×10?12 m2/s (Very Low risk).
• Carbonation Depth: 1.2 mm after 1 year (ensures 75-year design life).
• Salt Scaling Resistance: 0.8 kg/m2 after 50 cycles (passes ASTM C672).

6. Key Challenges & Solutions

? Slow Early Strength with 70% GGBFS → Micro silica (5%) and controlled curing improved hydration. ? Micro Silica Workability Issues → Optimized PCE superplasticizer dosing enhanced consistency. ? RCA Variability → On-site AI-powered sorting reduced contamination risks.

7. Lessons Learned & Policy Recommendations

? GCC-wide GGBFS/micro silica exchange hubs for better supply chain management. ? Updated coastal durability standards to mandate chloride resistance testing. ? Development of alkali-activated binders using desert silica and red mud.

8. Conclusion: The Future of Sustainable Concrete in MENA

This study confirms that high-GGBFS, micro silica-enhanced concrete meets MENA’s performance and sustainability goals. By leveraging industrial byproducts, advanced admixtures, and climate-adaptive production methods, MENA can:

?? Cut concrete-related emissions by 50% by 2040. ?? Align with COP28 decarbonization targets. ?? Support sustainable urban expansion (NEOM, The Line, Masdar City, Cairo 2050). ?? Reduce lifecycle costs and drive green infrastructure investments.

Future Outlook: Scaling this approach across MENA’s mega projects can drive net-zero construction and enhance infrastructure resilience in extreme climates.