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Rapid-1 Hardening Accelerator Concrete
Admixture
| The Need |
SIKA Rapid-1 Concrete Admixture
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The New Jersey Department of
Transportation needed a special concrete to be used in highway reparations that could be
poured and reopened to traffic in less than 6 hours. They found that full depth, full lane
highway repairs could be reopened without altering the concrete's materials, production,
placement, or finishing operations. Additionally, precast and prestressed producers were
looking for a special concrete that could shorten curing times and lower overall
production costs. |
The Technology
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SIKA Rapid-1 is a concrete admixture that allows
the development of very early high strengths in concrete consisting of commonly used
mix components. Unlike concrete set accelerators, it does not reduce set time or long-term
strength, and it does not corrode steel reinforcing. This hardening accelerator allows
placement of fresh concrete without early stiffening, followed by a
period of very rapid strength gain after initial set. Sika Rapid-1 is non-chloride
(non-corrosive) and will not limit the long term strength gain of concrete that is often
sacrificed when using set accelerators.
The advantages and benefits amount to a placeable concrete for improved production with
less manpower and very early high strengths achieved
without performance tradeoffs. In addition to the benefits for ready mixed
concrete, the hardening accelerator offers advantages to precast/prestressed concrete
producers. Sika Rapid-1's interaction with the cement hardening process occurs during the
hydration phase after initial set, and results in
additional internal heat generation. This heat is used to reduce or eliminate the cost of
steam curing, and/or shorten curing times. Highway contractors can place full-depth
concrete that is ready for traffic or paving operations in under six hours. |
The Benefits
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- Allows an initial strength increment during the first 12 hours
of 100% compared to a test concrete.
- Outperforms 50% to 100% the performance of regular chloride
based concrete accelerators.
- The faster reopening of the highway repairs reduces signaling
costs.
- The product can be use in combination with a superplasticizer
without modifying its properties.
- Provides a reduction in heat and thermic insulation costs.
- Allows a faster utilization of concrete forms. It allows an
increase in production of precast elements due to its higher initial strength.
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Status
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This technology won the 1997 NOVA Award from
the Construction Innovation Forum. The product
complies with the following specifications: EN934-2 (Swiss), ASTM C-494 Type C (U.S.A.)
and AASHTO M-194 Type C (U.S.A.) |
Points of Contact
- Todd C. Spindler, Marketing Manager - Concrete, Sika
Corporation, 201 Polito Avenue, Lyndhurst, NJ 07071. Phone: (201) 933-8800
References
- Construction Innovation Forum web site. www.cif.org.
- SIKA corporation web site: www.sikausa.com
- SIKA The Edge - Innovative Solutions for a Concrete World.
Sika Newsletter. July 1997. Issue No. 1.
- Everett, John G. (1997) "Speeding Up Concrete."
Construction Business Review. Vol. 7, Number 3.
Disclaimer Statement
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Neither the Construction
Industry Institute nor Purdue University in any way endorses this
technology or represents
that the information presented can be relied upon without further investigation. |
LHM
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