To mitigate and control alkali-silica reactivity (ASR) in concrete
RASIR® is a liquid admixture that can mitigate and control ASR in concrete when using potentially reactive aggregates or sand with high or moderate-alkali cement or where there are sources of external alkalies. RASIR® is a 30% lithium nitrate solution. RASIR® weighs approximately 10 lbs/gal (1.2 kg/L).
- Where aggregates are susceptible to ASR
- With high/moderate alkali cement in geographic areas that could contribute to ASR
- Where there are external sources of alkali such as deicing salts, alkaline cleaners or marine environments
- Weather conditions (freezing and thawing/wetting and drying cycles)
- Traffic loading
- Critical structures
- Road, bridges, highways, parking garages
- Airport runways
- Water treatment facilities
- Dams, piers and docks
The addition rate of RASIR® will depend on several factors including the alkali concentration of cement, cement content of the concrete, aggregate reactivity and the use of supplementary cementitious materials. ASTM tests should be performed in order to determine an accurate RASIR® addition rate when modifications to either of the above are made. Recommended tests are USACE CRD-C 662 and ASTM C1293 (modified for the testing of this admixture).
Inaccurate dosage rates of RASIR® are likely if these tests are not properly modified. Contact your GCP Applied Technologies representative for a copy of the recommended test methodology or for assistance in specifications.
Due to the wide variation of materials, admixtures and mix designs, we recommend that mix designs be appropriately tested prior to the project start.
An initial estimate of the required dosage rate of RASIR® may be obtained from the following equation:
RASIR® Dosage Equation =
(α* β * δ)/100 in gal/yd3 or L/m3
α = Amount of cement to be mixed (lb/yd3 or kg/m3)
β = Alkali content of cement (%) from either the cement mill certificate or from testing (to be more accurate)
δ = For gal/yd3 = 0.55 and for L/m3 = 4.6
For example, for a mix containing 600 lbs. of cement with an alkali content of 0.60%, the standard dose is 2.0 gallons of RASIR® per cubic yard.
600 x 0.60 x 0.55/100 = 2.0 gal/yd3
To maintain the same water-to-cement ratio, subtract 0.84 gallons of water for each gallon of RASIR® added.
Due to the wide variety of admixtures and mix designs, pretesting of the concrete mix will provide the user with data on plastic and hardened concrete properties. RASIR® has no general or significant adverse effects on concrete properties; however, the addition of RASIR® to a concrete mix may accelerate the set time of the concrete. Therefore, testing the concrete mix design prior to production is recommended.
Compatibility with Other Admixtures
RASIR® may be used with most GCP admixtures, as well as with fly ash or silica fume to help control ASR. The optimum level of pozzolans to help mitigate ASR should be determined by appropriate ASTM methods.
It is recommended that RASIR® be added separately to the concrete mix, usually through the water holding tank discharge line, and preferably at the end of the batch sequence. However, it may be added at other times in the batching sequence if testing shows acceptable performance. Please see GCP Technical Bulletin TB-0110, Admixture Dispenser Discharge Line Location and Sequencing for Concrete Batching Operations, for further recommendations.
A complete line of accurate, automatic dispensing equipment is available.
RASIR® is available in bulk, drums and totes.
Storage and Handling
Temperature: RASIR® will freeze at 20 ºF (-7 ºC). Do not use pressurized air for agitation. Shelf life: minimum of 12 months, depending on storage conditions.
Please contact your GCP Applied Technologies representative.
gcpat.com | North America Customer Service: 1 877-4AD-MIX1 (1 877-423-6491)
We hope the information here will be helpful. It is based on data and knowledge considered to be true and accurate, and is offered for consideration, investigation and verification by the user, but we do not warrant the results to be obtained. Please read all statements, recommendations, and suggestions in conjunction with our conditions of sale, which apply to all goods supplied by us. No statement, recommendation, or suggestion is intended for any use that would infringe any patent, copyright, or other third party right.
RASIR is a trademark, which may be registered in the United States and/or other countries, of GCP Applied Technologies Inc. This trademark list has been compiled using available published information as of the publication date and may not accurately reflect current trademark ownership or status.
© Copyright 2018 GCP Applied Technologies Inc. All rights reserved.
GCP Applied Technologies Inc., 62 Whittemore Avenue, Cambridge, MA 02140 USA.
In Canada, 294 Clements Road, West, Ajax, Ontario, Canada L1S 3C6.
This document is only current as of the last updated date stated below and is valid only for use in the United States. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on www.gcpat.com. Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.
Last Updated: 2021-02-05