Sustainability and Resilience

 Dear respectful Experts:

        Motivated  by the recent ASCE CEU invaluable course "Mitigation of Carbon Emissions from Construction Projects", I revisited my concrete mix design methodology, with a focus on performance-based sustainability. Dr. James A. D'Loisio's insights emphasized reducing embodied carbon through SCMs, avoiding over specification, and minimizing concrete volume where structurally feasible, recommending engineers to find further solutions . Building on this,I conducted three experimental trials using ASTM C494 Type F chemical admixture and the DOE method, targeting 25 MPa compressive strength for fresh concrete:

· Trial I: Nominal mix without admixture

· Trial II: Reduced cement with partial admixture dosage

· Trial III: Full admixture dosage with optimized w/c ratio

Key Findings:

1. Performance-Based Metric: 

Proposed CO₂-e/MPa offers a more meaningful sustainability metric than CO₂-e/m³, aligning with SE 2050 reporting and performance-based design principles.

2. CO₂-e Reduction via Hydration Efficiency:

 Trial II achieved ~31% reduction in CO₂-e/MPa and Trial III achieved ~46%. These results confirm Type F admixture's role in enhancing hydration efficiency and reducing embodied carbon.

3. Hydration-Based Modeling :

 CO₂-e stem from calcination ( CaCO₃ → CaO + CO₂^↑ ), not hydration.

Type F admixture enhances C-S-H formation, reducing unreacted clinker and improving strength per unit cement.

4. Carbon Reduction Factor (CRF) Proposed :

Unlike generic emissions reporting, CRF normalizes environmental impact based on actual hydration performance, enabling mix-specific benchmarking across diverse design contexts.

I propose a quantifiable metric for admixture sustainability performance:

   CRF_{type F} = [CO₂-e _Controle- CO₂-e _trial ] / Admixture dosage 

  The proposed units (kg CO₂-e reduced per kg of admixture per m³ of concrete) provide a consistent basis for design integration and comparison.

5. Water Reduction as a Primary Design Lever:

 Optimizing water content, directly influences hydration efficiency and CO₂-e performance, an actionable variable for designers.

6. Life Cycle Efficiency (LCE) Enhancement:

 Improved early strength and reduced cement demand support longer service life and lower total carbon footprint, aligned with ISO 14040/44 and EN 15978.

7. Codification Pathway This framework:

 provides the technical basis for future integration into:

   · ASTM C494 (Admixture classification)

   · SE 2050 Commitment Program

   · ACI 318 & ASCE 7 (Structural design integration)

   · NRMCA Guidelines

   · ISO 14067 (Carbon footprint of products)

Ongoing Work and Future Directions:

· Durability Testing: Long-term performance indicators (e.g., chloride permeability, shrinkage) are under evaluation.

· Structural Scaling: A case study applying a Trial III mix to a 10,000 sq ft slab is planned to demonstrate real-world CO₂e savings.

· Generalizability: CRF values will vary by cement type, SCM blend, admixture brand, and target strength. The framework is designed to be adaptable across materials and regions.

These findings are undergoing further validation for submission to an ASCE journal (e.g., Journal of Materials in Civil Engineering). I welcome professional feedback, methodological inquiries, and strategic recommendations to strengthen both technical depth and institutional impact. I am particularly interested in feedback on the proposed Carbon Reduction Factor (CRF) metric and the durability testing protocol.

Warmest regards,

 Abubakr Elfatih Ahmed Gameil, R. Eng, M. ASCE, SEI

#SignificantProjects
#ResilientInfrastructureSystems
#StrategicIssuesandPublicPolicy
#ClimateAdaptationPracticesandFinancing
#Decarbonization
#BuildingCodeAdvancementandAdoption[vertical]
#Standards
#MeasuringandMaintainingInfrastructureforSustainabilityandResilience
#Performanceobjectivesanddesigninginfrastructureforfunctionalrecovery
#EmergingTechnologies
#SustainableInfrastructure
#EmbodiedCarbonandGreenhouseGases
#ClimateMitigation
#InnovativeMaterials

------------------------------
Abubakr Gameil, R. ENG, M. ASCE®️, SEI Member
Chairman & Director General
Almanassa Engineering International Co. Ltd
Khartoum, Sudan
------------------------------

Hello Abubakr,

Thank you for sharing your insightful work on performance-based sustainability and the Carbon Reduction Factor (CRF). Your experiments clearly demonstrate the potential for significant CO₂-e reduction through optimized admixture use and hydration efficiency. It is inspiring to see practical, quantifiable metrics being proposed for integrating sustainability into concrete design.

As someone working on developing tools to assess long-term economic and operational impacts of sustainable materials in construction, I am particularly interested in how your CRF metric could be combined with lifecycle cost or durability analyses.

A question I have: in your ongoing durability testing, do you plan to integrate repair frequency or maintenance costs over time as part of evaluating the long-term sustainability of the mixes? This could provide an interesting bridge between environmental and economic assessment, similar to lifecycle cost modeling in building projects.

I would be glad to exchange insights or discuss potential synergies between lifecycle economic assessment and CRF-based carbon reduction metrics.

Warm regards,
Darya Stanskova

------------------------------
Darya Stanskova M.ASCE
Cost Estimator, Construction Engineer, Power Engineer, Project Manager
Fort Myers FL
------------------------------

Original Message:
Sent: 08-30-2025 11:07 AM
From: Abubakr Gameil
Subject: Codifying Carbon Reduction in Concrete: Hydration-Based CO₂-e Modeling, and CRF Definition for SE 2050 and ASTM C494 Integration

 Dear respectful Experts:

        Motivated  by the recent ASCE CEU invaluable course "Mitigation of Carbon Emissions from Construction Projects", I revisited my concrete mix design methodology, with a focus on performance-based sustainability. Dr. James A. D'Loisio's insights emphasized reducing embodied carbon through SCMs, avoiding over specification, and minimizing concrete volume where structurally feasible, recommending engineers to find further solutions . Building on this,I conducted three experimental trials using ASTM C494 Type F chemical admixture and the DOE method, targeting 25 MPa compressive strength for fresh concrete:

· Trial I: Nominal mix without admixture

· Trial II: Reduced cement with partial admixture dosage

· Trial III: Full admixture dosage with optimized w/c ratio

Key Findings:

1. Performance-Based Metric: 

Proposed CO₂-e/MPa offers a more meaningful sustainability metric than CO₂-e/m³, aligning with SE 2050 reporting and performance-based design principles.

2. CO₂-e Reduction via Hydration Efficiency:

 Trial II achieved ~31% reduction in CO₂-e/MPa and Trial III achieved ~46%. These results confirm Type F admixture's role in enhancing hydration efficiency and reducing embodied carbon.

3. Hydration-Based Modeling :

 CO₂-e stem from calcination ( CaCO₃ → CaO + CO₂^↑ ), not hydration.

Type F admixture enhances C-S-H formation, reducing unreacted clinker and improving strength per unit cement.

4. Carbon Reduction Factor (CRF) Proposed :

Unlike generic emissions reporting, CRF normalizes environmental impact based on actual hydration performance, enabling mix-specific benchmarking across diverse design contexts.

I propose a quantifiable metric for admixture sustainability performance:

   CRF_{type F} = [CO₂-e _Controle- CO₂-e _trial ] / Admixture dosage 

  The proposed units (kg CO₂-e reduced per kg of admixture per m³ of concrete) provide a consistent basis for design integration and comparison.

5. Water Reduction as a Primary Design Lever:

 Optimizing water content, directly influences hydration efficiency and CO₂-e performance, an actionable variable for designers.

6. Life Cycle Efficiency (LCE) Enhancement:

 Improved early strength and reduced cement demand support longer service life and lower total carbon footprint, aligned with ISO 14040/44 and EN 15978.

7. Codification Pathway This framework:

 provides the technical basis for future integration into:

   · ASTM C494 (Admixture classification)

   · SE 2050 Commitment Program

   · ACI 318 & ASCE 7 (Structural design integration)

   · NRMCA Guidelines

   · ISO 14067 (Carbon footprint of products)

Ongoing Work and Future Directions:

· Durability Testing: Long-term performance indicators (e.g., chloride permeability, shrinkage) are under evaluation.

· Structural Scaling: A case study applying a Trial III mix to a 10,000 sq ft slab is planned to demonstrate real-world CO₂e savings.

· Generalizability: CRF values will vary by cement type, SCM blend, admixture brand, and target strength. The framework is designed to be adaptable across materials and regions.

These findings are undergoing further validation for submission to an ASCE journal (e.g., Journal of Materials in Civil Engineering). I welcome professional feedback, methodological inquiries, and strategic recommendations to strengthen both technical depth and institutional impact. I am particularly interested in feedback on the proposed Carbon Reduction Factor (CRF) metric and the durability testing protocol.

Warmest regards,

 Abubakr Elfatih Ahmed Gameil, R. Eng, M. ASCE, SEI

#SignificantProjects
#ResilientInfrastructureSystems
#StrategicIssuesandPublicPolicy
#ClimateAdaptationPracticesandFinancing
#Decarbonization
#BuildingCodeAdvancementandAdoption[vertical]
#Standards
#MeasuringandMaintainingInfrastructureforSustainabilityandResilience
#Performanceobjectivesanddesigninginfrastructureforfunctionalrecovery
#EmergingTechnologies
#SustainableInfrastructure
#EmbodiedCarbonandGreenhouseGases
#ClimateMitigation
#InnovativeMaterials

------------------------------
Abubakr Gameil, R. ENG, M. ASCE®️, SEI Member
Chairman & Director General
Almanassa Engineering International Co. Ltd
Khartoum, Sudan
------------------------------