CMAX® Cement Q45 additive is a cementitious powder that increases the strength, shortens the set times, adds durability and decreases the shrinkage of standard concrete mix designs. CMAX® Cement Q45 is the perfect addition for mix designs that need to achieve high strengths quickly – as strong as 3,000 PSI in 60 minutes and an initial set time as fast as 20 minutes. CMAX® Cement Q45 can be used with retarder additives to provide longer workability, while still achieving high early strengths, making this an ideal product for time‐sensitive projects. CMAX® Cement Q45 is a made in the USA product.
Q45™ Cement Additive FAQ’s
Q # 1: What is Q45™?
A: Q45™ is an additive used with Portland cement concrete to enhance the physical and chemical properties related to high-early strength and durability. All Q45™ reactions with Portland cement and with its own ingredients are completed in aqueous solution, so Q45™ is regarded as a hydraulic cementitious material per ASTM C 219.
Q # 2: How does Q45™ work?
A: Q45™ is a rich Calcium Sulfate Aluminum compound. Upon mixing with Portland cement components, a very strong cementitious matrix is generated.
Q # 3: What is the chemical analysis of Q45™?
A: The following table gives the chemical analysis range for all ingredients:
| SiO2 | 10 – 12 % |
| Al2O3 | 24 – 26 % |
| Fe2O3 | 3 – 4 % |
| CaO | 42 – 45 % |
| MgO | 0.5 – 1.0 % |
| SO3 | 16 – 18 % |
| K2O | 0.2 – 0.3 % |
| Na2O | 0.2 – 0.3 % |
Q # 4: Is Q45™ related to High Alumina Cement?
A: Q45™ a CSA material with qualities of fast setting and high early strength development are not related to High Alumina cement, even though the Aluminum Oxide content is higher than the range of that of Portland cement. High Alumina cement is a refractory cement with a completely different microscopic crystal structure. Calcium Aluminate Cement is made by fusing or sintering alumina and calcia contributing minerals to produce monocalcium aluminate (CaAl2O4) clinkers that are subsequently ground into a powder. This CAC material is superior to Portland cement in its setting properties and its ability to withstand high temperatures and chemical attack. CAC-containing cements are compounded for many applications in construction and refractories. The amount of active monocalcium aluminate (and therefore the CaO and impurity content) determine the service temperature of a cement compound. Advances in particle size distribution and packing technology and increases in alumina content have made it possible to greatly reduce the CAC percentage in mixes while improving mechanical performance and increasing service temperatures to more than 1900 C.
Q # 5: Is there any chloride component in Q45™ to which fast setting quality could be attributed?
A: There are no Chloride components in Q45™, the qualities of fast setting and early high strength are attributed to a different hydration mechanism. Q45™ has all the advantages of the Chloride accelerator but to a much higher extent and without the adverse consequences of using Chloride like excessive shrinkage or steel erosion.
Q # 6: What is the shrinkage behavior of Q45™ concrete mixes?
A: Q45™ has a shrinkage reducing quality on concrete mixes. The shrinkage of Q45™ in concrete mixes is at least three times less than that of Portland cement mixes for the same water/cement ratio.
Q # 7: Is Q45™ related to type K shrinkage compensating cement?
A: Q45™ is a volume stable cement. There is no expansion to counterbalance the shrinkage behavior of Portland cement. Q45™ has a totally different mechanism of reducing the shrinkage related to the special quality of Patented® crystals.
Q # 8: What is the setting time for Q45™ mixes?
A: Upon mixing Q45™ with Portland cement, a wide range of setting time is achieved depending on the percentages of the two components. The table in the next question encompasses the conceivable range without using any retarding agent.
Q # 9: What is the strength range of Q45™ mixes?
A: The following table provides useful information regarding the strength of Q45™ mixes using different percentages of Portland cement. All data was obtained per ASTM C-109 for w/c=0.35 and W. R. Grace plasticizer Adva 100 for a dose of 15 oz/100 lbs. of cement. No retarding agent was used:
| Q45™ | Setting Time | 3 Hrs. (psi) | 24 Hrs. (psi) | 28 Days (psi) |
| 20 % | 45 Min. | 1710 | 4510 | 6470 |
| 30 % | 40 Min. | 2670 | 3080 | 6970 |
| 40 % | 35 Min. | 3450 | 4500 | 7450 |
| 50 % | 30 Min. | 4150 | 5870 | 9250 |
| 60 % | 20 Min. | 4660 | 6300 | 9780 |
Q # 10: How could the working time for Q45™ concrete be extended?
A: The working time for Q45™ concrete mixes could be extended in two ways:
- -Reducing the mix temperature by using chilled As a rule of thumb, working time would increase by a minute for every minute drop in concrete temperature.
- – Use the retarding agent UC Delay™ in the proper dose estimated in ounces per 100
lbs. of cement. The following table illustrates the approximate dose of delay for one hour of working time. Since site conditions and the aggregate qualities affect the setting time largely, actual concrete test pours should be conducted to determine the delay dose for specific site conditions.