Admixture for Precast FRP concrete
Posted by Alokjit on August 30, 2006
I am a small manufacturer of Precast Concrete article. I want to manufacture Fibre reinfoced polymer concrete Manhole covers, Drain Covers etc. Will you help me by giving information of ratio for Concrete, Polymer and what type admixure should be used for the same. We have used Sika admixture for so many projects and earlier we were your approved applicator in India. We done some job at the time of constructing Goa factory. Name: Alokjit Dey. email: dey_alokjit@rediffmail.com or jolienco_cal@yahoo.ca. Please response to question. With Regard. Alokjit
Dear Mr. Alokjit,
This has reference to your question regarding "Admixtures for Precast FRP concrete".
The most commonly used polymer to make polymer modified concrete is a latex polymer, which is added to the concrete during mixing. Generally, the solid content of the latex polymer is in the range of 40 - 55%. The dosage range of solid polymer latex in concrete is from 10% to 25% by weight of cement depending on the properties desired.
Addition of latex polymer increases the workability of the concrete, so the water to cement ratio should be reduced appropriately. If you are looking for a higher water reduction than what is achieved by using the latex polymer, you can use either a water reducing or high range water reducing admixture. For more specific details on the dosage of the polymer and admixture, please follow the suppliers/ manufacturer's recommendations.
Polymer modified concretes have good resistance to water and have good bonding properties, so they popularly used for repair jobs or waterproofing jobs (eg. basement waterproofing)
If you are planning to use polymer in concrete to just improve its resistance to water ingress, another economical alternative would be to use either an integral waterproofing compound or a superplasticizer and reduce the water to cement ratio of the concrete to improve its water tightness. You can also use materials like Fly ash and slag at appropriate levels, which also help to reduce permeability.
Thanks and good luck.