concrete lab report

Department of Civil & Environmental Engineering

Laboratory Report Cover

Wet/Hardened Concrete Lab

CEGR 3255-L01

Structural Materials Laboratory

Submitted By: Kyle Indingaro Date Performed: Sep. 21, 2016 Date Submitted: Nov. 30, 2016

Lab Partners: Aaron Butler Ethan CreedGarrett HoneycuttJacob LevanAlex Rosenberger

Instructor: Dr. Erika Weber Grade: ___________________T.A.: Houston Sims

I, Kyle Indingaro, have committed no violations of the UNC Charlotte Code of Student Academic Integrity in preparing and submitting this report.

Signature: _____________________________

Date: _______________________________

Executive Summary

This report examines the properties of wet and hardened concrete to determine if the

properties meet their design requirements for the application of an exterior column with a

compressive strength of 3,000 psi. The properties of wet concrete evaluated were workability,

density, yield, specific gravity, and air content. The tests/methods used to determine these

properties were the slump test (ASTM C143), gravimetric test (ASTM C138) and the air

pressure test using the pressure method (ASTM C231), respectively. For hardened concrete, the

evaluated properties were compressive strength, modulus of elasticity (MOE), tensile strength,

and modulus of rupture (MOR). The tests/methods used to determine these properties were the

compressive test (ASTM C39), splitting tensile test (ASTM 2496), and MOR test (ASTM C78),

respectively.

The slump test conducted on the wet concrete measured a slump of 4 inches. The 4-inch

slump was within ASTM standard range which expressed a concrete mix with a sufficient

workability.

Density, yield, and specific gravity were calculated to be 151.68 pcf, 1.18 ft3/batch, and

2.43, respectively. The tested property values of density, yield, and specific gravity were

accurate to their theoretical values of 150 pcf, 1.25 ft3/batch, and 2.40, respectively.

The air content was measured from both the gravimetric test and the pressure method

which resulted in values of 3.18% and 1.90%, respectively. Both tests indicated a large

discrepancy to the desired 5%, however, the gravimetric test provided accurate values for

density, yield, and specific gravity, thus the 3.18% should be considered the more accurate value.

ii

The compressive strength of hardened concrete was found to be 5,940.325 psi which

surpassed the design requirement of 3,000 psi. The compressive strength of the concrete was

appropriate for the intended project.

The tested MOE of the hardened concrete was 120,485 psi which was dangerously below

the design requirement of 2,240,960 psi. Based on the severe difference in values, it should be

assumed that the tested MOE is inaccurate due to faulty testing procedures.

The tested tensile strength of the hardened concrete was 468.752 psi which exceeded the

design requirement of 366.970 psi. The tensile strength of the hardened concrete was appropriate

for the intended project.

For the MOR of the hardened concrete, the tested capacity was 860.648 psi which

surpassed the design requirement of 657.270 psi. The MOR of the hardened concrete was

appropriate for the intended project.

Based on the air content and the MOE being below the design requirements, it is

recommended that the mix proportions be reconstructed to incorporate a larger percentage of air,

and that the MOE be retested to determine an accurate value.

iii

Table of Contents

Introduction………………………………………………………………………………………..1

Procedures…………………………………………………………………………………………5

Results…………………………………………………………………………………………....12

Analysis & Conclusion………………………………………………………………………......13

References…………………………………………………………………………...…………..R1

Appendix……………………………………………………………………………..………….A1

iv

Introduction

Concrete is one of the most commonly used materials in construction and is often utilized

in columns, retaining walls and foundations. Megastructures such as the Panama Canal, the

Hoover Damn and the Burj Khalifa have all been designed using concrete. Concrete was initially

utilized by the Romans to innovate the model civilization of the time and has continuously been

modified to enhance the infrastructure of civilizations that followed. Along with being a low-cost

material, the raw ingredients of concrete can be found in nearly every country on Earth, making

it a material of choice for many projects. How these simple components of concrete are mixed

together can make the difference between tragedy and triumph (Nat. Geo 2015).

Concrete is a heterogeneous mixture usually made up of aggregates, cement, water, and

admixtures. When concrete is initially mixed, it is considered to be in its “wet” state where

hardening has yet to occur and the product is in a viscous state. In this state, the concrete has no

compressive strength even though the aggregate within has a high compressive strength. The

general rule for hardening is that the concrete will reach its relative maximum compressive

strength after 28 days (Somayaji, 2001).

This report examines concrete in both a wet and hardened state for the application of an

exterior column with a compressive strength of 3,000 psi. The purpose of this report is to

determine if the tested material properties of wet and hardened concrete meet their design

requirements for the specified project. The evaluated properties of fresh concrete are workability,

density, yield, specific gravity, and air content. The evaluated properties of hardened concrete

are compressive strength, modulus of elasticity (MOE), splitting tensile strength and modulus of

rupture (MOR).

1

Slump testing of wet concrete provides a description of the concrete’s “workability”

which is the ability of the concrete to be mixed, handled, transported and placed with a minimum

loss of homogeneity. The slump indicates how much the wet sample “slumps” downward when

it is unrestricted. A highly saturated mix will result in a “collapse slump” where the mixture will

collapse on itself. This indicates that the mixture has an excessive amount of water which forces

the aggregate particles to separate from each other. Opposite to a collapse slump, a “1-inch

slump” occurs when the mixture slumps very little or not at all. This type of slump expresses a

dry mixture which can be corrected with the addition of water and/or admixtures (Somayaji,

2001).

The density of concrete is a ratio of the mass of the material used in mixing to the volume

of the observed specimen. The density has a direct correlation to the concrete’s compressive

strength, expressing that a higher density results in a higher compressive strength. The weight of

hardened concrete is directly proportional to the density of wet concrete. Higher density leads to

heavier concrete members which creates larger loads on those members. A density that is too

large will directly produce a load that was not intended to be within the system of the member.

The design of the member/structure is a direct result of the anticipated loads on the system. If an

increased load that is not considered is applied to the system, the design will fail.

Concrete yield represents the volume of wet mixed concrete from a known quantity of

ingredients. Mixed concrete is sold based on the volume of wet concrete, so yield testing is

utilized by consumers to assure they receive the proper amount from their provider. In this

report, the tested yield is compared to the volume of the wet mixture produced by the aggregates,

cement, and water (CIP, 2000).

2

Bulk specific gravity is the ratio of the mass of a substance (concrete) relative to the mass

of an equal volume of water at the same temperature. The bulk specific gravity obtained from the

gravimetric test is important in determining the concrete’s classification. Rather than observing

specific gravity, bulk specific gravity is observed in the experiment since the aggregate within

the mix does not undergo any physical or chemical changes (Somayaji, 2001).

The property of air content is defined as the percentage of air within the concrete

compared to the overall volume of the sample. Air content generally accounts for 2-8% of the

overall volume of the mixture (Somayaji, 2001). Maximum air content of the concrete is

determined based on parameters such as location of the concrete, freeze/thaw affects and

aggregate size. If a concrete mix contains an air content of at least 3%, it is considered “air

entrained.” Entrained air within the concrete provides relief to pressure caused by expanding

moisture during freeze/thaw cycles (PCA, 1998). The concrete will either experience “moderate

exposure” or “severe exposure” to moisture which determines the designed air content. A larger

percentage of air content is required in concrete that experiences heavier amounts of water

exposure (Somayaji, 2001).

Compressive strength of hardened concrete is the ability of the concrete to withstand a

compressive load without breaking. If the compressive strength does not meet the design

requirements, the project will fail in compression. Test results for compressive strength are

examined to determine if the concrete mixture meets the requirements of the specified strength in

the job specification. The tested value is compared to the design value to determine if the

mixture meets the specifications required. Requirements for concrete compressive strength can

range from 2,500 psi for residential projects to 4,000 psi for commercial projects (CIP, 2003).

3

The MOE of hardened concrete is a measurement of the concrete’s stiffness. The MOE is

important to concrete because it expresses the ability of the concrete to resist deformation in

response to an applied load. According to Somayaji, the MOE of the hardened concrete depends

primarily on the modulus of both the aggregates and paste used within the mixture. As coarser

aggregate is used in a design, the MOE will increase. Other factors that will increase the MOE

are density, age, and strength of the concrete (Somayaji, 2001).

Tensile strength testing of hardened concrete provides the maximum tensile strength that

the concrete can withstand. Due to thermal reactions that can cause expansion in the concrete,

tensile strength should be large enough to resist cracking. If tensile strength does not meet the

design requirements, cracking can occur which would diminish the stability of the concrete. A

general rule is that the tensile strength is approximately 10-15 percent of the concrete’s

compressive strength, indicating that concrete is much stronger in compression than in tension.

Considering that concrete is weaker in tension than in compression, it will initially

rupture (or break) where tension occurs. The MOR (also known as the flexural strength) is the

largest bending stress experienced prior to rupture. The MOR is affected by several variables

such as the water-to-cement ratio, and the age of the hardened concrete. The tested capacity for

MOR expresses whether-or-not the concrete can withstand certain bending stresses.

4

Procedures

Tests were conducted to evaluate the properties of wet concrete which included

workability, density, yield, specific gravity, and air content. Once hardening occurred, tests were

conducted to evaluate the properties of hardened concrete which included compressive strength,

MOE, splitting tensile strength, and MOR.

Concrete Mix Design (ASTM C192):

Components Required:

Scale

Buckets (4)

Mixer

Procedure:

1. The weight of the empty buckets, coarse aggregate, fine aggregate, cement, and water

were determined.

2. The coarse aggregate was brought to SSD condition.

3. Roughly half of the coarse aggregate and ¼ of the water was placed in the mixer before it

was turned on.

4. After mixing the coarse aggregate and water for one minute, all the cement and fine

aggregate was placed in the mixer along with the remaining coarse aggregate.

5. The components were mixed for 2 minutes while the remaining ¾ of water was

periodically added to the mixture when it appeared dry.

6. After the mixer was turned off, the mix was stood for 2 minutes.

7. The mixture was then mixed for 2 more minutes.

5

Slump Test (ASTM C143):


Slump Cone and Base

Tampering Rod

Ruler

Procedure:

1. The entire slump cone and base was dampened with water.

2. While securing the slump cone to the base, the cone was filled 1/3 of the way to the top

and then rodded 25 times with the tampering rod three separate times until the cone was

full.

3. The excess concrete was leveled off from the top of the cone by using a horizontal cutting

motion with the tampering rod.

4. The cone was then immediately lifted vertically from the base.

6

Gravimetric Density/Yield/Specific Gravity/Air Content (ASTM C138):


Scale

Ruler

Volumetric Air Meter

Tampering Rod

Rubber Headed Mallet

Graduated Cylinder

Procedures:

1. The measuring bowl was filled evenly two separate times until full.

2. After each fill, the concrete was rodded 25 times and the sides of the bowl were lightly

tapped with the rubber mallet 10-15 times.

3. The excess concrete was leveled off from the top of the measuring bowl using a

horizontal cutting motion with the tampering rod.

7

Air Content Using the Pressure Method (ASTM C231):


Type B Pressure Meter

Tampering Rod

Rubber Headed Mallet

Wash Bottle

Procedure:

1. The entire pressure meter was dampened with water.

2. The measuring bowl of the pressure meter was filled 1/3 of the way to the top and rodded

25 times with the tampering rod three separate times until the bowl was full.

3. The bowl was lightly tapped 4 times evenly around the measuring bowl.

4. The excess concrete was leveled off from the top of the measuring bowl using a

horizontal cutting motion with the tampering rod.

5. The pressure meter was sealed to the measuring bowl and the air valves at the top were

closed while the petcocks were left opened.

6. Water was sprayed with the wash bottle into one petcocks until the water came out the

other petcock.

7. With the petcocks still open, the bleeder valve was closed and the pump of the pressure

meter was used to raise the gauge to an initial air reading until it stabilized.

8. The petcocks were then closed and the main air valve was opened.

9. The sides of the bowl were evenly tapped 4 times with the rubber mallet.

10. A new reading was taken from the pressure gauge.

8

Cylinders (ASTM C31):


Cylinder

Tampering Rod

Scoop

Procedures:

1. Form release was applied in the cylinder’s mold.

2. The mold was filled 1/3 of the way to the top and rodded 25 times with the tampering

rod three separate times until the cylinder was full.

3. The excess concrete was leveled off from the top of the cylinder using a horizontal

cutting motion with the tampering rod.

Prism (ASTM C1314-16):


Prism Mold

Scoop

Vibrator

Procedures:

1. Form release was applied to the inside and outside of the far ends of the mold.

2. Using the scoop, the mold was filled with the fresh concrete.

3. The vibrator was used to compact the mix.

9

Concrete Compressive Strength (ASTM C39):


Caliper

Ruler

Universal Testing Machine (UTM)

Procedure:

1. The diameter and length of cylinder were measured with the caliper and ruler.

2. The cylinder was vertically centered in the UTM.

3. The UTM applied a load to the cylinder until failure was reached.

Concrete Splitting Tensile Strength (ASTM C496):


Caliper

Ruler

UTM

Procedure:

1. The diameter and length of cylinder were measured with the caliper and ruler.

2. The cylinder was horizontally centered in the UTM.

3. The UTM applied a load to the cylinder until failure was reached.

10

Concrete Modulus of Rupture Tensile Strength (ASTM C78):


Caliper

Ruler

UTM

Procedure:

1. The prism’s depth, width, and length was measured.

2. Locations of the supports, loading point loads and the top surface of the prism were

marked.

3. The loading apparatus was positioned with the prism placed horizontally on the supports.

4. The prism was loaded gradually until failure.

11

Results

Table 1 expresses the results for the evaluated properties that were tested on wet

concrete. These properties include workability, density, yield, specific gravity, and air content.

Table 2 expresses the tested capacities of the hardened concrete compared to their designed

requirements. These properties include compressive strength, MOE, tensile strength, and MOR.

Table 1. Experimental values for the evaluated properties of wet concrete.

Experimental Value

Slump (in) 4.00

Density (pcf) 151.68

Yield (ft3/batch) 1.18

Specific Gravity 2.43

Gravimetric Air Content (%) 3.18

Pressure Method Air Content (%) 1.90

Table 2. Tested capacities of hardened concrete compared to their designed capacities.

Property Tested Capacity Design Requirement

Compressive Strength (psi) 5,940.325 3,000.00

Modulus of Elasticity (psi) 120,485 2,240,960

Tensile Strength (psi) 468.752 366.970

Modulus of Rupture (psi) 860.648 657.270

12

Analysis & Conclusion

Properties of wet and hardened concrete were evaluated to determine if the tested

material capacities met their design requirements for the intended use as an exterior column with

a maximum compressive strength of 3,000 psi. The tested properties of wet concrete were

workability, density, yield, specific gravity, and air content. The tested properties of hardened

concrete were compressive strength, MOE, splitting tensile strength, and MOR.

The wet concrete’s slump was measured at 4 inches which was within the range outlined

by ASTM standard. The 4-inch slump represents a mix composition with a sufficient

workability.

The calculated density of the wet concrete was 151.68 pcf which was accurate to the

theoretical value of 150 pcf. The experimental value for the density should be considered

sufficient based on its accuracy to the theoretical value.

The calculated experimental yield was 1.18 ft3/batch which was relatively accurate to the

theoretical value of 1.25 ft3/batch. The difference in yield values could be the result of an

incorrect mix proportion. Too much or too little of an ingredient would alter the density, thus

changing the yield. The results calculated for the experimental yield should be considered within

acceptable range of the theoretical yield with negligible error.

The experimental specific gravity was calculated to be 2.43 which was accurate to its

theoretical value of 2.40. The calculated specific gravity is sufficient with minor error which

should be considered negligible.

Designing for an exterior column that experiences “moderate” water expose, the air

content for the fresh concrete should have been approximately 5%. The gravimetric test and

pressure method resulted in a 3.18% and 1.90% air content, respectively. These values are both

13

imprecise and inaccurate to the 5% air content, however, it can be observed that the gravimetric

test provided accurate values for density, yield, and specific gravity. Considering these accurate

property values, the gravimetric test should be considered the more accurate method. From the

gravimetric test, the air content of the wet mix (3.18%) is less than the desired 5%. This

discrepancy could be a result of inaccurate mix proportions or from additional air voids that were

not released when the sides of the measuring bowl were tapped. The error expressed from the

pressure method could be a cause of faulty testing procedures/components. Complications with

the pressure gauge occurred during testing which could have produced inaccurate results. Based

on the tested air content from the gravimetric test, it is recommended that the mix composition

be reconstructed to incorporate a larger percentage of air.

The tested compressive strength of the hardened concrete was 5,940.325 psi which was

greater than the design requirement of 3,000 psi. Because the tested capacity was much larger

than the design requirement, the compressive strength for the hardened concrete is sufficient for

the intended project.

The design requirement for the MOE was 2,240,960 psi, however, data collected from the

compressive tests expressed a MOE of only 120,485 psi. It should be assumed that the severe

discrepancy between the design requirement and tested capacity is a result of faulty testing

procedures. It is recommended that testing be redone.

The tested capacity of the splitting tensile strength was 468.752 psi which exceeded the

design requirement of 366.970 psi. Because the tested capacity was greater than the design

requirement, the concrete’s tensile strength is sufficient for the intended project.

14

The tested capacity for the MOR was 860.648 psi which surpassed the design

requirement of 657.270 psi. Because the tested capacity was greater than the design

requirement, it is expected that the hardened concrete will be able to withstand certain bending

stresses associated with the intended project.

Properties of wet and hardened concrete were tested to determine if they met their

respective design requirements for the application of an exterior column with a compressive

strength of 3,000 psi. The tested properties of wet concrete were workability, density, yield,

specific gravity, and air content. The tested properties of hardened concrete were compressive

strength, MOE, splitting tensile strength, and MOR. Testing results shows that the only two

properties that did not meet their respective design requirements were the air content and the

MOE. It is recommended that the concrete’s mix composition be reconstructed to incorporate a

larger percentage of air and that the hardened concrete’s MOE be retested.

15

References

ASTM Standard C31, 2003, "Standard Practice for Making and Curing Concrete Test Specimens

in the Field," ASTM International, West Conshohocken, PA, 2003, DOI:10.1520/C0033-

03, www.astm.org.

ASTM Standard C39, 2003, "Standard Test Method for Compressive Strength of Cylindrical

Concrete Specimens," ASTM International, West Conshohocken, PA, 2003, DOI:

10.1520/C0033-03, www.astm.org.

ASTM Standard C78, 2003, "Standard Test Method for Flexural Strength of Concrete," ASTM

International, West Conshohocken, PA, 2003, DOI: 10.1520/C0033-03, www.astm.org.

ASTM Standard C143, 2003, "Standard Test Method for Slump of Hydraulic-Cement Concrete,"

ASTM International, West Conshohocken, PA, 2003, DOI: 10.1520/C0033-03, www.astm.org.

ASTM Standard C192, 2003, "Standard Practice for Making and Curing Concrete Specimens in

the Laboratory," ASTM International, West Conshohocken, PA, 2003, DOI: 10.1520/C0033-

03, www.astm.org.

ASTM Standard C231, 2003, "Standard Specification for Air Content or Freshly Mixed Concrete

by the Pressure Method,” ASTM International, West Conshohocken, PA, 2003, DOI:

10.1520/C0033-03, www.astm.org.

R1

http://www.astm.org/






ASTM Standard C496, 2003, "Standard Test Method for Splitting Tensile Strength of

Cylindrical Concrete Specimens," ASTM International, West Conshohocken, PA, 2003, DOI:

10.1520/C0033-03, www.astm.org.

ASTM Standard C1314-16, 2003, "Standard Test Method for Compressive Strength of Masonry

Prisms," ASTM International, West Conshohocken, PA, 2003, DOI: 10.1520/C0033-

03, www.astm.org.

"Concrete in Practice: What, Why and How?" CIP 35 – Testing Compressive Strength of

Concrete. NRMCA, 2003. <http://www.nrmca.org/aboutconcrete/cips/08p.pdf>. (November 6,

2016)

National Geographic (2015). “Megastructures – Science of Concrete.”

<https://www.youtube.com/watch?v=qlg-fEgK2W4> . (November 30, 2016)

Portland Cement Association (1998). “Concrete Technology Today.”

<http://www.cement.org/docs/default-source/fc_concrete_technology/pl981.pdf?sfvrsn=2>

(September 26, 2016)

Somayaji, S. (2001). Civil Engineering Materials, 2nd Ed. Upper Saddle River, New Jersey.

Pages (48-60).

R2



Appendix I – Gravimetric Test Calculations

Table 3: Measured variables collected from gravimetric testing.

Weight of Measuring Bowl (lb) 7.8700Weight of Concrete + Measuring Bowl (lb) 45.335

Weight of Concrete (lb) 37.465Volume of Bowl (ft3) 0.24700

Table 4: Proportions of concrete mix used with their specific gravity and calculated volume.

Weight (lb) Specific Gravity * Volume (ft3)

Water 15.2 1.00 0.244Cement 30.7 3.15 0.156

Coarse Aggregate 76.3 2.71 0.451Fine Aggregate 57.2 2.46 0.373

Ʃ = W1 = 179.4 - ƩV = 1.22

* Volume calculations listed below:

V water=Wwater

SGwater∗62.4 pcf= 15.2lb

1∗62.4 pcf=0.244 ft3

V cement=W cement

SGcement∗62.4 pcf= 30.7 lb

3.15∗62.4 pcf=0.156 ft3

V CA=WCA

SGCA∗62.4 pcf= 76.3 lb

2.71∗62.4 pcf=0.451 ft3

V FA=W FA

SGFA∗62.4 pcf= 57.2 lb

2.46∗62.4 pcf=0.373 ft3

A1

Density ( ρ )=W concrete

V bowl= 37.465lb

0.24700 ft3=151.68 pcf

Yield=

W 1

27∗ρ=( 179lb

27 yd3

ft3 ∗151.68 pcf )∗27=1.18 ft3

batch

SpecificGravity= ρ62.4 pcf

=151.68 pcf62.4 pcf

=2.43

TheoreticalUnitWeight (t)=W 1

ƩV=179.4 lb

1.22 ft3 =147 pcf

AirContent=(|t−ρ|t )∗100=(|147 pcf−151.68 pcf|

147 pcf )∗100=3.18 %

Table 5. Properties calculated from the gravimetric test compared to their theoretical values.

Experimental Value Theoretical ValueDensity (pcf) 151.68 150.00

Yield (ft3/batch) 1.18 1.25Specific Gravity 2.43 2.40Air Content (%) 3.18 5.00

A2

Appendix II – Compressive Strength Tested Equations

Table 6. Measured data from the compressive test.

Cylinder #1 Cylinder #2Diameter of Cylinder (in) 4.0 4.0Length of Cylinder (in) 8.0 8.0

Ultimate Load (lb) 73,374.44 75,922.22

Compressive Strength Tested Equations:

Compressive StrengthCylinder ¿1= PA

= 73,374.44 lbπ∗4∈¿2

4=5,838.952 psi¿

Compressive StrengthCylinder ¿2= PA

= 75,922.22lbπ∗4∈¿2

4=6,041.698 psi ¿

Avg .Compressive Strength=5,838.952 psi+6,041.698 psi2

=5,940.325 psi

A3

Appendix III – Modulus of Elasticity Tested Equations

0.012 0.014 0.016 0.018 0.02 0.022 0.024 0.026 0.028 0.030

1000

2000

3000

4000

5000

6000

7000

Cylinder #1 - Stress v. Strain

Strain (in/in)

Stre

ss (p

si)

Figure 1: Stress v. strain curve for Cylinder #1 representing the yield point at the tested capacity.

Table 7. Variables gathered from Figure 1 to determine modulus of elasticity.

Cylinder #1Ultimate Load (lbf) 73,374.44Stress at Strain of 0.0005 in/in (psi) 24.40217Stress at 40% of Ultimate Load (psi) 2,335.581Strain at 40% of Ultimate Load (in/in) 0.020125

Tested Modulus of Elasticity Cylinder ¿1=2,335.581 psi−24.40217 psi0.020125∈¿∈−0.00005

=120,484.6 psi

A4

0.01 0.015 0.02 0.025 0.03 0.0350.000

1000.000

2000.000

3000.000

4000.000

5000.000

6000.000

7000.000

Cylinder #2 - Stress v. Strain

Strain (in/in)

Stre

ss (p

si)

Figure 2: Stress v. strain curve for Cylinder #2 representing the yield point at the tested capacity.

Table 8. Variables gathered from Figure 2 to determine modulus of elasticity.

Cylinder #2Ultimate Load (lbf) 75,922.22Stress at Strain of 0.0005 in/in (psi) 24.42950Stress at 40% of Ultimate Load (psi) 2,416.680Strain at 40% of Ultimate Load (in/in) 0.0190600

Tested Modulus of Elasticity Cylinder ¿2=2,416.68 psi−24.4295 psi0.019060∈¿∈−0.00005

=125,842.7 psi

Avg .Tested Modulus of Elasticity=120,484.6 psi+125,842.7 psi2

=120,484.6 psi

A5

Appendix IV – Splitting Tensile Strength Tested Equations

Table 9. Measured data from the splitting tensile test.

Cylinder #3 Cylinder #4Diameter of Cylinder (in) 4.0 4.0Length of Cylinder (in) 8.0 8.0Ultimate Load (lb) 25,880.84 21,243.27

Figure 3: Splitting tensile test for Cylinder #3 expressing the ultimate load and extension.

A6

Figure 4: Splitting tensile test for Cylinder #4 expressing the ultimate load and extension.

Tensile Strength Tested Equations:

Tensile StrengthCylinder ¿3= 2Pπld

= 2×25,880.84 lbfπ ×8.0∈×4.0∈¿=514.8830 psi ¿

Tensile StrengthCylinder ¿4=2 Pπld

= 2×21,243.27 lbfπ ×8.0∈×4.0∈¿=422.6214 psi¿

Avg .Tensile StrengthCylinder=514.8830 psi+422.6214 psi2

=468.7522 psi

A7

Appendix V – Modulus of Rupture Tested Equations

Table 10. Measured data from the modulus of rupture test.

Prism #1Depth of Prism (in) 6.0Width of Prism (in) 6.0Length of Prism (in) 20.0

Span Length of Prism (in) 18.0Ultimate Load (lbf) 9,295

Modulus of Rupture Tested Equation:

Modulusof Rupture=9295 psi×20.0∈ ¿6.0×6.02 =860.6481 psi ¿

Figure 5: Modulus of rupture test expressing the yield point at the ultimate load for Prism #1.

A8

concrete lab report

Documents