28 JPCL November 2014 / paintsquare.com

otating equipment andheavy machinery cannotsimply be installed on a

concrete foundation since irregularitiesin both the machine base and concretesurface will create load-bearing issuesand alignment difficulties. Additionally,a concrete foundation is not toughenough to withstand the compressiveand dynamic loading needed to sup-port the heavy machinery. For this rea-son, machinery bases are aligned andleveled by shims or jack bolts abovethe mechanically prepared concrete

foundation and the resulting spacebetween the machine base. This spaceis filled with a machinery grout for loadand energy transfer from the equipmentinto the foundation. The grout must be fluid enough to be

poured or pumped under the baseplateto completely fill this space and mustalso maintain its volume throughout theservice life of the equipment to ensureintimate contact between these surfacesfor maximum load-bearing capability.Additionally, the grout must exhibit thenecessary mechanical properties such

as high ultimate compressive strengthsover a variety of application and servicetemperatures.One of the challenges of quality

machinery grouting is proper materialselection for lasting security, stabilityand alignment of the critical equipmentit supports. All grout manufacturerspublish physical properties of their prod-ucts, determined either from tests per-formed in-house or by an independenttesting laboratory. But these propertiesare not uniformly reported, as many ofthese tests are modified and different

MachineryFoundationGrouting

Performance Solutions that Challenge Movement

By Fred Goodwin & Frank Apicella, BASF Construction Chemicals

R

paintsquare.com / JPCL November 2014 29

test methods are used depending onthe grout composition (i.e., epoxy orcement). There is no clear justificationfor using different test methods tomeasure the same performance proper-ties between grouts when determiningsuitability of use. The test methodsspecified to determine the critical per-formance properties of any groutshould be dictated by the function andnot by the grout chemistry. This article compares the key perfor-

mance properties of two types of groutusing identical testing methods so that

a comparison of performance proper-ties can be made on an apples-to-apples basis to aid in selection of thebest grout for a particular application.Results are presented for an epoxygrout and an ultra-high strengthhydraulic grout (known as hybrid per-formance grout in this article).Interviews conducted with design pro-fessionals and con-tractors provided iden-tification of the follow-ing critical perfor-mance factors formachinery grouts:• CompressiveStrength• Creep Resistance • Modulus ofElasticity• Fatigue Resistance• Impact Resistance• Coefficient ofThermal Expansion• Flowability andBearing AreaCompressive

strength ranked as themost important prop-erty in material selec-tion, but flowabilityand bearing area arejust as critical. If thegrout can’t be placedproperly under thebase plate to supportthe machinery, does itreally matter what thecompressive strengthof the grout is?Therefore, the combination of factorsof compressive strength, flowabilityand bearing area together, are criticalfor overall long-term performance. Inaddition, for the grout to be durable, itmust be able to withstand the fatiguefrom repeated loading, resist impact

and have a compatible coefficient ofthermal expansion to the surroundingmaterials.

Compressive StrengthCompressive strength is a measure ofthe maximum load the grout can with-stand and is a significant predictor formany of the other critical performance

parameters. Most machinery grouts willexhibit compressive strengths of 5,000to 18,000 psi (34.5 to 124 MPa) to bearthe weight of the particular equipmentthey support.There are many ways to test for a

material’s compressive strength.

Fig. 2: This graph describes compressive strength affected by temperature.The hybrid performance grout was cured for 28 days at 73 F and theepoxy grout for 24 hours at 73 F, and then post cured 16 hours at 140 F.Both grouts were then conditioned for 24 hours at test temperature.

Fig. 1: This graph shows the compressive strength of both grout typesat 70 F as per ASTM C579, “Standard Test Methods for CompressiveStrength of Chemical Resistant Mortars, Grouts, Monolithic Surfacingsand Polymer Concretes.”

©iStockphoto/IngaNielsen

Having compressive strength proper-ties greater than the concrete founda-tion, does not guarantee satisfactoryperformance. The selection processmust take into account the serviceoperating temperature conditions ofthe grout. Very few large machines operate at

ambient conditions. The heat generat-ed by the equipment ultimately affectsthe foundation grout. The compressivestrength reported at laboratory condi-tions does not always reflect the com-pressive strength at operating tempera-tures, as shown in Figure 2 (p. 29). The epoxy grouts have reduced

compressive strength as the tempera-ture increases while the hybrid perfor-mance grout maintains its compres-sive strength even at much highertemperatures.As an industrial machine warms up

to its operating temperature, its align-

ment can be altered if the grout losesstrength with higher temperatures.Therefore the engineer should specifythe compressive strength of the foun-dation grout at the operating tempera-ture of the equipment.

Creep Resistance Creep resistance is a time-dependentmeasure of the dimensional change ofthe grout under constant load. It is apermanent, long-term deformation thata grout experiences over time.Excessive creep can cause equipmentmisalignment and loss of torque inanchor bolts. Creep is measured inmicrostrains where 1 microstrainequals 1 millionth of a unit length of

Different test methods and protocolsyield different results, so it is importantto specify a standard method to makea fair comparison between differentgrouts. These differences are due togeometries of the test specimens, suchas aspect ratio (ratio of the test speci-men’s length to the area loaded), andto the rate of loading.The ASTM test method for determin-

ing compressive strength in this studyis ASTM C579, “Standard TestMethods for Compressive Strength ofChemical Resistant Mortars, Grouts,Monolithic Surfacings and PolymerConcretes.” There are three differentmethods for determining compressivestrength in ASTM C579. Method B for2-inch (50-mm) cubes should be used,as this method is for the size of theaggregate commonly used in thesegrouts. The testing equipment shouldbe properly set for the travel rate of 0.2

inches per minute (5 mm per minute).Using travel rates higher than this canresult in artificially high compressivestrength values and create a risk ofselecting a grout that may have inade-quate compressive strength. Rigidmetal molds should always be usedwhen casting specimens. Avoid plasticinserts as the surfaces are not planarand can result in reduction of the test-ed strength.As Figure 1 (p. 29) illustrates, epoxy

grouts can reach over 12,000 psi (83MPa) after a few days of cure. Thehybrid performance grout has similarstrength development compared to anepoxy grout, but with a higher ultimatestrength.

30 JPCL November 2014 / paintsquare.com

Machinery Foundation Grouting

deflection occurring in 1 unit length ofmaterial (i.e., 1 microstrain equals 1 mil-lionth of an inch, per inch). Creep canultimately cause enough deflection in agrouted baseplate to adversely affectmachinery alignment resulting in pre-mature wear or failure of bearings andother rotating parts. There are several methods to deter-

mine the creep behavior of materialssuch as bricks, lumber, and concrete.Compressive creep for grouts should betested per ASTM C1181, “Standard TestMethods for Compressive Creep ofChemical-Resistant Polymer MachineryGrouts.” When specifying creep proper-ties, it is necessary to include the tem-perature and loading requirements asthese properties are not part of the testmethod and changing them can affectthe reported results. This way, materialscan be selected based on an equivalentcomparison (Table 1).The hybrid performance grout

exhibits extremely low creep comparedto an epoxy grout due to its highstrength and modulus over a widerange of temperature extremes. As operating temperatures increase,

so does creep. The same forces thatresult in lower compressive strengthalso accelerate permanent deformationof the grout under applied loads. Highcreep resistance at equipment operatingtemperatures is essential to maintainingcritical equipment alignment and long-term service life.

Modulus of Elasticity (MOE)Different types of testing methods areused to determine the modulus of amaterial. Selection of the right methoddepends on what type of stress is actingon the material. Shear stress should usemodulus of rigidity; volumetric stressshould be reported as bulk modulus,and direct stress as modulus of elastici-ty. The modulus of elasticity measuresthe ability of the grout to resist deflec-tion under load and is the measure ofthe “stiffness” of a grout. A higher mod-ulus material produces less deflectionunder a given load.

Table 1: Creep resistance tested using ASTM C1181

Epoxy Grout Hybrid Performance Grout

0.0035 in/in 0.0023 in/in

(3,500 microstrains) (2,300 microstrains)

ASTM C1181

600 psi, 140 F (4.1 Mpa, 60 C)

tance determines the ability of thegrout to resist cyclical loading undersimulated conditions of service forrotating or reciprocating equipment.Fatigue occurs when a material is sub-jected to repeat loading and unloading.If the loads are above a certain thresh-old, microscopic cracks will begin toform. Eventually these cracks will growto a critical size leading to fracture andreliability issues.The only standardized test to mea-

sure fatigue performance of groutingmaterials is the Det Norske Veritas:

For a givenload (stress), the higher the modulus thelower the deflection (strain). Modulus = Stress/Strain

Modulus psi

Steel 29 Million

Concrete 3 to 5 Million

Hybrid Performance Grout 5 Million

Epoxy Grout 1 to 2.5 Million

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MOE is tested per ASTM C580,“Standard Test Method for FlexuralStrength and Modulus of Elasticity ofChemical-Resistant Mortars, Grouts,Monolithic Surfacings, and PolymerConcretes.” Typical modulus values forsteel, concrete, epoxy grout and thehybrid performance grout are com-pared in Figure 3. The hybrid perfor-mance grout values are very close tothe modulus of concrete. Epoxy groutshave a modulus of elasticity lower thanconcrete and will exhibit more deflec-tion than the hybrid performance groutunder the same loading conditions.As an industrial machine warms up

to its operating temperature, its align-ment can be altered as the grout modu-lus decreases with higher temperaturesfor epoxy grouts. To some extent, areduced modulus helps grout absorband dissipate forces from operatingconditions; however a significant reduc-tion of modulus will adversely affectthe equipment as dynamic forces occur.Therefore grouts should be specifiedthat retain modulus at the highestexpected operating temperatures.

Fatigue ResistanceDuring their lifetime, grouts areexposed to millions of dynamic loadcycles that need to be transferred orabsorbed by the grout. Fatigue resis-

Fig. 3: Modulus of elasticity can be measured using ASTM C580, “Standard Test Method for FlexuralStrength and Modulus of Elasticity of Chemical-Resistant Mortars, Grouts, Monolithic Surfacings, andPolymer Concretes.” This test determines the ability of the grout to resist deflection under load. Toolow of a modulus can result in excess deflection.

73 F (25 C) 140 F (60 C) 170 F (77 C)

5 Million psi 2.1 Million psi 5 Million psi 1.7 Million psi 5 Million psi 0.8 Million psi

Fig. 4: This figure shows modulus of elasticity affected by temperature. Epoxy grout was cured for24 hours at room temperature and post cured 16 hours at 140 F. Hybrid performance grout wascured for 28 days at 73 F. Both grouts were then conditioned for 24 hours at test temperature.

Fig. 5: This figure displays the results of the impact resistance test performed as per ASTM C535 with the hybrid performance grout after 2,000 cylcles (top) and the steel impact balls used in the test.

25%

43%

DNV-OS-C502, “Offshore ConcreteStructures (DNV)” used in offshore windturbine structures. The DNV methoduses specimens cyclically loaded at 5 Hzfor 2,000,000 cycles. The epoxy and hybrid performance

grout were cyclically loaded at 40 per-cent of their ultimate compressivestrength with no damage.

Impact ResistanceThe impact resistance of grouts can bemeasured with the equipment of ASTMC131, “Standard Test Method forResistance to Degradation of Small-Size Coarse Aggregate by Abrasion andImpact in the Los Angeles Machine” orASTM C535 for coarse aggregate.When evaluating the impact resistanceof grouts, 2-inch (50-mm) cube speci-mens are prepared, weighed and

32 JPCL November 2014 / paintsquare.com

placed into a rotating steel drum con-taining 2-inch diameter steel ball bear-ings, and rotated at a speed of 32rpm. A shelf within the rotating drumcreates a crushing impact effect whilethe tumbling of the cubes with theball bearings creates abrasion. Afterevery 500 revolutions the cubes areremoved, weighed, and the drum iscleaned. This process is repeated for atotal of 2,000 revolutions. The epoxy grout lost 25 percent

mass while the hybrid performancegrout lost 43 percent mass. Theresults indicate that the epoxy grouthas higher impact resistance andtoughness than hybrid performancegrout (Fig. 5, p. 31).

Coefficient of Thermal ExpansionThe coefficient of linear thermal expan-

Machinery Foundation Grouting

Fig. 6: Coefficient of linear thermal expansion was tested using ASTM C 531 and recorded results of a temperature change from 73 F to 210 F.

sion (CTE) measures a length changeof a material as the temperaturechanges. Temperature changes in agrout occur diurnally, seasonally andfrom ambient-to-equipment operatingtemperatures. The CTE value repre-sents the amount each material willexpand or contract when a one-degreeincrease or decrease in temperatureoccurs. The CTE is expressed in unitscomparing the length change perdegree of temperature change (i.e.,inches per inch per degree F) of thematerial. The closer the CTE betweentwo materials, the more compatiblethey become over a wide range oftemperature changes. This is becausethey will tend to grow and shrink atthe same rate as the temperaturechanges. Materials in contact witheach other with significantly different

Fig. 7: Flowability and bearing area were tested using a head box (left) as per ASTM C1339.

paintsquare.com / JPCL November 2014 33

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CTEs experience stresses at the inter-face, which can lead to cracking orloss of bond. The hybrid performancegrout is much more dimensionallycompatible with steel and concreteover a wide range of temperaturescompared to the epoxy grout (Fig. 6,p. 32).

Flowability and Bearing AreaThe objective of foundation groutingis to achieve ease of placement andflowability in order to properly reachall areas to be grouted while the groutremains in contact with the baseplate. By obtaining maximum contact

underneath a baseplate, the groutedequipment is stable and any imposedloads are evenly distributed to thefoundation. This lengthens the life ofthe equipment, the grout and thefoundation. Bearing area and flowabil-ity are determined by ASTM C1339,“Standard Test Method for Flowabilityand Bearing Area of Chemical-Resistant Polymer Machinery Grouts.”In this test, the grout is pouredthrough a head box, a type of funnelthat creates hydraulic head to assistgravity flow into the defined grout cavity. The measured flow time is the

length of time that the grout takes toflow the length of the box and the filltime is how long the grout takes tocompletely fill the area under the sim-ulated baseplate. Once hardened, thebaseplate is removed and the groutsurface is abraded to open air bubblesand voids formed under the baseplate.The amount of effective bearing areais determined by visual comparison toa standard to estimate what percent-age of the grout would actually besupporting the baseplate (known aseffective bearing area, or EBA). Thehybrid performance grout’s flow char-acteristics and EBA are superior to anepoxy grout (Fig. 7, p. 32)

SummaryOne of the challenges of grouting isthe material selection based on criticalperformance properties. Many of the

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tests used to generate performanceproperties are commonly modifiedmaking the values not uniformlyreported. This creates difficulty whendesign professionals must makeinformed decisions regarding groutselection. Comparing key perfor-mance properties generated with the

same testing protocols, one can read-ily see where both the hybrid perfor-mance grout and epoxy grouts per-form well. Epoxy grouts offer excellent

strength development, durability andimpact resistance but can have per-formance gaps in creep resistance

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paintsquare.com / JPCL November 2014 35

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and elevated temperature service. Ahybrid performance grout can bridgethis performance gap in many situa-tions; as well as offer simplicity of pack-aging, mixing and cleanup.From a chemistry standpoint, hybridperformance grouts are based onhydraulically active minerals and addi-tives that provide for ultra-highstrength development with desirableplacement characteristics and perfor-mance in severe service environmentsrequired for today’s grouting of indus-trial equipment.

Fred Goodwin, fellow scientist, productdevelopment BASF ConstructionChemicals, is a chemist with over 30years of experience in the constructionchemicals industry, including cementmanufacture, research, developmentand technical support of grouts, adhe-

sives, coatings,shotcrete, stucco,flooring and con-crete repair materi-als. He has beenwith BASF and itspredecessors for 25years and is anactive member of

ICRI, ACI, ASTM, NACE, SDC and SSPC.Goodwin is a fellow of ACI and ICRI, anHonorary Member of ASTM C1 + C9,current chair of the ICRI TechnicalActivities Committee (TAC), ACI 515Protective Systems, ASTM C09.41Cement Based Grouts, SSPC 8.3Commercial Floor Coatings and a mem-ber of ACI TAC. Goodwin is also a guestlecturer for the Grouting Fundamentalsshort course (Colorado School ofMines) and was awarded the JPCLEditors Award in 2006, 2010, and 2012as well as the ACI 2011 Delmar BloemDistinguished Service Award. He is aNACE Corrosion Technologist, holdsfour U.S. patents and was named a TopThinker in JPCL’s Annual Bonus issueof 2012. Goodwin also frequentlyspeaks at national conventions.

Frank Apicella is the research and devel-

opment managerfor inorganicchemistry at BASFConstructionChemicals. He hasover 25 years ofexperience in thedevelopment of

hydraulic and polymer-based protec-tion and repair products for the con-struction industry including adhesives,coatings, concrete repair mortars,floors, composite systems, andmachinery grouts. He is an activemember of the ACI, SSPC, NACE andICRI. JPCL

Machinery Foundation Grouting

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