Secondary Waterproofing Admixtures, Uses, Advantages and Limitations


In the 21st century where increased knowledge in architecture and engineering has offered the building industry the opportunity to achieve hitherto unachievable architectural and engineering marvel, the place of admixtures cannot be under estimated. New building techniques and systems have only being made possible by advances in admixtures and construction chemicals. And with the increasing adoption of these new building practices especially in High rise buildings there is no gainsaying the fact that construction chemicals and admixtures will be in greater demand in the near future.

 

According to the American Concrete institute the highest standard setting body on matters that relates to concrete and steel construction in the world. Waterproofing admixtures can be classified into two namely PRAH (permeability reducing admixture with hydrostatic capacity) and PRAN (permeability reducing Admixtures without Hydrostatic capacity).This classifications is particularly contained in ACI 212 for your personal research.

This classification is significantly important, in that it provides a guide in choosing waterproofing admixtures in a market shrouded by mushroom products with many false claims. It is therefore important that Construction companies, engineers, consultants, architects and other professionals understand the classification and distinctions both by ACI and the British standard setting body BBA.

 

Further review of the ACI 212 waterproofing classification identifies admixtures that fall into PRAH and PRAN as quoted here

 

 

 

 

When to Use Secondary or Primary waterproofing Admixtures

According to chapter 15 of the ACI 212 report secondary waterproofing admixtures (PRAN) should only be specified or use in situations where the concrete will not be exposed to hydrostatic pressure both now and in the future. In other words area that are not below sea level and where the water table are not susceptible to rising.  Going by this definition it means that in areas like lekki, Ajah, Ikoyi, Victoria Island and in fact the whole of Lagos, Rivers, Delta, Ebonyi, Bayelsa, Cross River and all the riverine areas of Nigeria and some part of the Northern state it is recommended to use primary waterproofing admixtures .

It is only sensible that we use secondary waterproofing admixtures, in a situation that we are sure that the water table will not rise both now and in the future. However, because it is difficult to make this kind of prediction with any level of accuracy, it may be wiser to follow the ACI guidelines and stick with the secondary admixtures in most instances

 

Architects and structural engineers specifying for large scale projects, especially projects with basements will have to make the critical decisions on the choice of admixtures for the foundation, basements and other below grade area of their clients’ projects. When a wrong choice is made at this point, it may permanently hunt the project. Nothing is as frustrating as a leaking basement, paint peel off or dampness on a major project even before handing over to client. Usually this requires more effort and resources to fix and sometimes you may never get 100% result in fixing the leakages.

 

Aquafin AdmixQ100p is a third generation crystalline admixture that has been classified as PRAH by ACI 212 guide. Aquafin admix has high capacity for withstanding high hydrostatic pressure, It was particularly researched and designed for the tropical market such as Nigeria. Apart from the fact that it comes in concentrate, thereby giving you  double the usage volume, it also has several other advantages, such as helping to improve the concrete overall compressive strength, reduced chloride ion penetration, protecting the reinforcement from rusting, and helping to protect concrete and reinforcement from ASL attack.

Finally, it is important that professionals review and study the datasheets of waterproofing admixtures materials carefully before specifying them, this way we will know what we are specifying and the result we are expecting and ultimately we would have  saved our clients unnecessary headache both now and in the future by ensuring that we choose the right products.

 

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The table above is the ACI classification table for deciding the waterproofing capacity of different admixtures in the market. Third generation crystalline like Aquafin admix as classified offers the highest percentage reduction in permeability across all product category.  If you would like further information or you would like us to advise you on your choice of admixture for concrete work, please do not hesitate to contact us through the details below

www. actnigeria.com

info@actnigeria.com

012956197, 08182435430, 08182435381

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