When it comes to high-performance concrete, every detail matters — from workability and durability to resistance against freeze-thaw cycles. One of the most effective strategies to improve these properties is the use of air-entraining admixtures, and two products are standing out in this area: Carbofen Admix and Admix PRO, both developed by Polytrade Natural Resins.
In a recent technical evaluation conducted by GMG Engenharia e Consultoria Ltda., both admixtures demonstrated full compliance with ASTM C260, the internationally recognized standard for air-entraining agents in concrete.
Why Air-Entraining Admixtures Matter
Air-entraining admixtures introduce tiny, stable air bubbles into the concrete matrix. These microscopic voids significantly increase concrete’s resistance to freeze-thaw damage, improve workability, and reduce permeability — all of which contribute to longer service life, especially in harsh environments.
To be considered reliable, these admixtures must comply with strict criteria — and ASTM C260 is the benchmark that sets those standards.
The Study: Objectives and Approach
The aim of the study was to evaluate and compare the performance of:
- Carbofen Admix
- Carbofen Admix PRO
- Vinsol Flakes (widely used as a reference standard)
Each admixture was diluted to the same solid content (8.33%) and tested under controlled conditions using standardized materials and methods.
Materials Used
- Cement: CP V ARI, with 90–100% clinker content
- Aggregates: Natural/manufactured sand and crushed granite per ASTM C33
- Water: Distilled for paste testing; potable for concrete
- Admixtures: Carbofen samples were saponified with 50% NaOH at 80°C
Testing Standards Applied
The tests were carried out following ASTM guidelines:
- ASTM C260 – Standard Specification for Air-Entraining Admixtures
- ASTM C192 – Concrete sample preparation
- ASTM C231 / C138 – Air content and density
- ASTM C143 – Slump test
- ASTM C666 – Freeze-thaw resistance
- ASTM C39 / C78 / C157 – Strength and shrinkage
- ASTM C232 – Bleeding
- ASTM C403 – Setting time
Key Results
Fresh Concrete Properties
| Property | Range Achieved |
| Air Content | 2.5% – 6.0% |
| Slump | 80 – 140 mm |
| Density | 2290 – 2390 kg/m³ |
| Temperature | 28.1 – 29.5°C |
| Relative Humidity | 79% – 85% |
Hardened Concrete Performance
Compressive Strength (MPa)
| Age | Carbofen Admix | Admix PRO |
| 1 day | 8.53 | 11.33 |
| 3 days | 14.50 | 22.70 |
| 7 days | 17.90 | 24.80 |
| 28 days | 24.70 | 35.80 |
Flexural Strength (MPa)
| Age | Carbofen Admix | Admix PRO |
| 3 days | 3.51 | 3.92 |
| 7 days | 3.84 | 4.12 |
| 28 days | 4.23 | 5.49 |
Setting Time (vs reference)
| Parameter | ASTM Limit (±1h15) | Carbofen Admix | Admix PRO |
| Initial set | ±75 minutes | -44 min | -22 min |
| Final set | ±75 minutes | -22 min | +5 min |
Freeze-Thaw Durability
| Parameter | ASTM Requirement | Carbofen Admix | Admix PRO |
| Durability Factor | ≥ 80% | 99.5% | 98.2% |
| Relative Durability | ≥ 90% | 100% | 98.2% |
Bleeding (ASTM C232)
| Admixture | Bleed Rate | ASTM Limit |
| Carbofen Admix | 0.2% | ≤ 2.0% |
| Admix PRO | 0.3% | ≤ 2.0% |
Conclusion: Certified Performance You Can Trust
Both Carbofen Admix and Admix PRO not only passed all ASTM C260 criteria — they outperformed expectations. From strength development to durability and setting time, these products delivered results comparable to or even better than traditional reference admixtures.
Why Choose Carbofen Solutions?
✅ Compliant with international standards
✅ Excellent freeze-thaw resistance
✅ Low bleeding rates
✅ Superior strength performance
✅ Sustainable, natural-based composition
✅ Perfect alternative to petroleum-based products
Ready to Elevate Your Concrete?
Whether you’re working on infrastructure exposed to harsh weather or simply aiming to improve your concrete mix design, Carbofen Admix and Admix PRO are powerful tools for engineers, architects, and concrete producers alike.
Contact our team today to request technical documentation, samples, or assistance in choosing the ideal admixture for your project.