EQUIPMENT
FOUNDATION
SYSTEMS
130 Commerce Drive • Montgomeryville, PA 18936 • 215-855-8450 • Fax: 215-855-4688
Technical Bulletin #
638D
Bulletin
Description
All major epoxy grouts on the market today have sufficient Compressive Strength to bear the weight of the
equipment they support. It is more important compare grouts based on how compatible they are with both
the concrete and steel it is connected to. Therefore, the most important design criteria for an epoxy grout
are those physical properties that directly affect the grout's compatibility with concrete and steel;
Coefficient of Linear Thermal Expansion and Peak Exotherm.
Coefficient
Of Expansion
Coefficient of Linear Thermal Expansion (CTE) is the amount something will expand or contract when it is
subjected to a 1F increase or decrease in temperature. It is expressed in units of inch per inch, degree
of temperature change of the material. The following is a listing of the CTE's for concrete, steel and various
epoxy grouts as published by their respective manufacturers:
The closer the CTE of two materials are, the more compatible those materials are. They are compatible
because they will tend to grow and shrink together as the outside temperature increases and decreases.
Peak
Exotherm
Peak Exotherm (PE) is the maximum temperature that an epoxy reaches during its cure. This is also the
point at which the epoxy changes from liquid to solid. The equipment operating temperature that produces
no thermal stress is be equal to the peak exotherm temperature for that epoxy. For this reason,
CHOCKFAST RED and ESCOWELD 7505E/7530 were formulated to have the lowest peak exotherm
possible (95F to 130F depending on depth).
Grout Compatibility with Concrete & Steel
CHOCKFAST
Red & ESCOWELD 7505E/7530
CONCRETE
STEEL
CHOCKFAST RED
OTHER EPOXY GROUTS
5.9
6.1
11.2
16.9
28
ESCOWELD 7505E/7530
14.5
Coefficients of Linear Thermal Expansion
(in./in.°F x 10
-6
)
EQUIPMENT
FOUNDATION
SYSTEMS
CF Red Compatibility with Concrete
Bulletin No. 638D, Page 2
Application
Instructions
Because CHOCKFAST Red and ESCOWELD 7505E/7530 are gently curing epoxy grouts, their peak
exotherm temperatures are usually very close to the foundation temperature underneath operating
equipment. This small difference between the peak exotherm temperature and the operating temperature
results in minimum foundation stress.
When machinery is not operating, freezing conditions may occur. In this case, the epoxy grout will want to
contract more than the concrete or steel because it has a higher CTE's. As a result of the epoxy bond to
the concrete, the epoxy will be put into compression and the concrete into tension.
If the temperature drops far enough, the epoxy may build up sufficient tension to crack, or shear the bond
line with the concrete. By using expansion joints installed in accordance with ITW Performance Polymers'
procedures, stress cracking can be avoided and longer life can be expected from properly designed
foundations. Please see Bulletins No. 662 and 645 for more information on expansion joints.
Example
Calculating Linear Contraction of Epoxy
The following example calculates the Linear Contraction of epoxy grout starting at the grout’s Peak
Exotherm and returning to a foundation temperature of 70F. The formula for Linear Contraction is:
Linear Contraction (in/in) = Coefficient of Thermal Expansion (CTE) X Change in Temperature (T)
Grout
CTE
T (PE - 70)
Linear Contraction
CHOCKFAST RED
11.2 x 10
-6
in/in/F x
(95 - 70)F =
28.0 x 10
-5
in/in
Other Epoxy Grout
27.0 x 10
-6
in/in/F x
(210 - 70)F =
378.0 x 10
-5
in/in
This shows that the linear contraction of the competitive grout is 13 times as more than the linear
contraction of the CHOCKFAST Red. Of course, if the foundation temperature were 95F, there would be
no linear contraction of CHOCKFAST Red.
Conclusion
A foundation that is healthy over the long-term is the result of a low peak exotherm coupled with a low
Coefficient of Linear Thermal Expansion. CHOCKFAST Red and ESCOWELD 7505E/7530 were
formulated to maintain these properties in single pours 18" deep if necessary. The compatibility of these
grouts with concrete ensures a problem-free foundation for many years of operation.
Date
June 2018
General: Every reasonable effort is made to insure the technical information and
recommendations on these data pages are true and accurate to the best of our
knowledge at the date of issuance. However, this information is subject to change
without notice. Prior versions of this publication are invalid with the release of this
version. Products and information are intended for use by qualified applicators that
have the required background, technical knowledge, and equipment to perform said
tasks in a satisfactory manner. Consult your local distributor for product availability,
additional product information, and technical support. Warranty: ITW Performance
Polymers, a division of Illinois Tool Works Inc., warrants that its products meet their
printed specifications. This is the sole warranty. This warranty expires one year after
product shipment. Warranty Claims: If any product fails to meet the above, ITW
Performance Polymers will, at its option, either replace the product or refund the
purchase price. ITW Performance Polymers will have no other liability for breach of
warranty, negligence, or otherwise. All warranty claims must be made in writing within
one year of the date of shipment. No other claims will be considered. Disclaimer: ITW
Performance Polymers makes no other warranty, expressed or implied, and specifically
disclaims any warranty of merchantability or fitness for a particular purpose.
Suggestions concerning the use of products are not warranties. The purchaser
assumes the responsibility for determining suitability of products and appropriate use.
ITW Performance Polymers’ sole liability, for breach of warranty, negligence or
otherwise, shall be the replacement of product or refund of the purchase price, at ITW
Performance Polymers’ election. Under no circumstances shall ITW Performance
Polymers be liable for any indirect, incidental or consequential damages. Modification
of Warranty: No distributor or sales representative has the authority to change the
above provisions. No change in the above provisions will be valid unless in writing and
signed by an officer or the Technical Director of ITW Performance Polymers. No term
of any purchase order shall serve to modify any provision of this document. Mediation
and Arbitration: If any dispute arises relating to products or product warranties, either
the purchaser or ITW Performance Polymers may a) initiate mediation under the then
current Center for Public Resources (CPR) Model Procedure for Mediation of Business
Disputes, or b) initiate a non-binding arbitration under the rules of the American
Arbitration Association for the resolution of commercial disputes.
...Epoxy Grout shrinks faster than concrete
...which forces the concrete to
restrict the shrinking of the Epoxy
When the temperature drops...
o
F
The Epoxy is in
Compression
The Concrete is in
Tension