B08_PEFO_267538_Atch_14_CMU___Mortar_Testing_Report.pdf

111 SW Fifth Avenue, Suite 2600 Portland, OR 97204 503 227 -3251 kpff.com

PETROGRAPHIC EXAMINATION OF MORTAR AND CONCRETE

MASONRY UNIT SAMPLES

PAINTED DESERT COMMUNITY CENTER – PETRIFIED FOREST NATIONAL

PARK

APRIL 15, 2024

PROJECT SCOPE

As requested, KPFF has examined one (1) mortar sample and (2) concrete masonry unit (CMU) fragments removed from the Painted Desert Community Center in Petrified Forest National Park, Arizona. The objectives of the examination were to determine:

• The physical and chemical properties of the mortar.

• If any deleterious reactions were present that would affect the durability of the mortar.

• The physical and chemical properties of the CMU.

• The air void structure and content and porosity associated with exterior surface absorption.

PART 1 –SAMPLE IDENTIFICATION

One (1) mortar sample and (2) CMU fragments were received for testing on March 22, 2024. The sample descriptions are given in Table I and shown as received in Photo 1.

TABLE I – SAMPLE IDENTIFICATION

Sample

ID

Wt.

(g)

Width

(in)

Length

(in)

Thickness

(in)

Notes

Mortar 339 3.11 4.29 0.9 Dark brown/red mortar extracted from vehicle storage SE corner.

CMU-1 - 3.64 7.73 1.39

Light brown/red CMU with sand exposed at exterior surface and mortar adhered to long surfaces. Foam adhered to one short side of fragment.

CMU-2 - 3.63 7.74 1.40

Light brown/red CMU fragment with sand exposed at exterior surface. Grey Resin material adhered to exterior surface at (2) areas.

Painted Desert CC Petrified Forest National Park 2 KPFF Project No. 10022400221 Petrographic Examination of Mortar and CMU April 15, 2024

Photo 1. Photo of samples mortar(left) CMU-1 (middle) and CMU-2(right) fragments shown as received.

PART 2 – MORTAR ANALYSIS

The composition of the mortar sample was determined according to ASTM C 1324, “Standard Test

Method for Examination and Analysis of Hardened Masonry Mortar,” which incorporates chemical analysis and examination of “thin-sections” by polarized light microscopy (PLM). The following information was obtained:

a) The sample represented hydrated lime/portland cement paste with siliceous sand aggregate.

b) The sand consists mainly of quartz, feldspar, volcanic rock fragments. The aggregate was well graded.

c) The sand grains were sub-round and stable without clay or other deleterious minerals.

d) The mortar had a moderate hardness with a Mohs Hardness of 3 and the aggregate-to-paste bond was strong.

e) The mortar represented by the sample was dark brown/red with a high concentration of colorless sand and tan sand. The mortar was pigmented with a red/brown iron oxide.

f) The aggregate was uniformly distributed throughout the mortar.

g) No deleterious reactions or secondary mineralization were detected. No dolomitic lime or other magnesium minerals were detected.

h) The paste was heavily carbonated.

e) The samples were not air entrained and had low concentration of entrapped air voids.

f) Based on the chemical analysis, the volumetric proportions of the mortar represented by the sample were approximately:

1.0 Portland Cement: 0.93 Hydrated Lime: 4.33 parts sand.

g) The mortar’s composition most closely matches a Type N mortar.

Painted Desert CC Petrified Forest National Park 3 KPFF Project No. 10022400221

h) Photo 2 consist of photomicrographs showing the typical microstructures of mortar sample.

i) The Rinko & Associates chemical analysis report is attached as Appendix A.

Photo 2 – Photomicrograph showing typical microstructure of mortar sample. Image taken at 400x magnification plane-polarized light (left) and cross-polarized light (right).

PART 3 – SAND GRADATION

The gradation of the sand component of the mortar samples was determined according to a modified

ASTM C 136, “Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates.” The sand was extracted from the mortar sample by crushing the sample and immersing in an acid bath. Photo 3 shows the extracted sand from the sample at 8x magnification. The sample was primarily composed of the minerals quartz and feldspars. The rest of the sand was composed of volcanic rock types and appeared red and black. The primary coloring of the mortar is due to an iron oxide pigment that was separated from the rest of the sand sample extraction as it was finer than #200 sieve size. The sieve analysis was conducted by Terracon and the report is attached as Appendix B.

Photo 3 – Photomicrograph showing extracted sand from the mortar sample. 8x magnification.

Painted Desert CC Petrified Forest National Park 4 KPFF Project No. 10022400221

PART 4– PETROGRAPHIC ANALYSIS OF MASONRY BLOCK

The concrete represented by the samples was examined following procedures described in ASTM C 856, “Standard Practice for Petrographic Examination of Hardened Concrete.” The following information was obtained:

a) The concrete represented by the block samples was composed of portland cement paste and light-weight siliceous coarse aggregate and normal-weight fine aggregate. A pigment was observed throughout the cement paste that altered the matrix color to a red/tan.

b) The concrete was well proportioned with distribution of coarse aggregate consistent through the area of the samples with no signs of segregation. Consolidation was good with entrapped air voids well distributed.

c) The aggregate consisted of 3/8" maximum size round to sub-round coarse aggregate with a lithology dominated by expanded shale. The fine aggregate was composed of quartz, feldspar, expanded shale, sandstone, pyroxene, and opaque minerals.

d) The average total air content was approximately 16.8%. Approximately 2.3% of the voids observed were spherical and less than 0.04” in diameter and the rest of the air voids were irregular in shape and varied in size. The concrete was not purposefully air entrained.

e) On average the concrete represented by the samples was composed of approximately 21% cement paste and 62% aggregate, by volume. The paste contained ~0.04mils red/brown particles at an approximate concentration of 20% of the matrix. The particle size is beyond the capability to resolve in optical microscopy and are most likely pigments added to the concrete during batching. Photo 4 is a photomicrograph of the matrix of Sample CMU-1.

f) The average volumetric coarse-to-fine aggregate ratio (CA/FA) was approximately 1.7:1. The volumetric proportions are given in Table II.

g) The cement paste was pink/tan in color and was hard, with a Mohs Hardness of 5. The aggregate-to-paste bond was good. Microcracking was rarely observed.

h) The amount of unhydrated portland cement (UPC) clinker in the cement paste was approximately 8-9%. Overall, the paste was well hydrated (adequately cured) and had moderate capillary void porosity (paste was moderately dense).

Painted Desert CC Petrified Forest National Park 5 KPFF Project No. 10022400221

Photo 4 – Photomicrograph showing the matrix for sample CMU-1. Unhydrated portland cement grain, Belite cluster (red arrow) is shown at the right of the image. Red/brown circular particles measuring less than 0.04mils are scattered throughout the matrix and is indicative of and iron oxide pigment. Image taken at 400x magnification plane-polarized light (left) and cross-polarized light (right).

TABLE II - Volumetric Proportions

Sample ID CMU-1

Paste Content, % 20.9

Coarse Aggregate Content, % 38.9

Fine Aggregate Content, % 23.1

Entrained Air (spherical voids with diameters < 1 mm), % 2.3

Entrapped Air (irregular shaped voids or diameters > 1 mm), % 14.8

Total, % (includes air) 100.0

Coarse-to-fine aggregate ratio (CA/FA) 1.7:1

Total Air Content, % 17.1

Total Aggregate Content, % 62.0 water-cementitious material ratio (w/cm) 0.40

Estimated cementitious material content (sacks/yd³) 5.3

i) Heavy carbonation of the cement paste was measured at the exterior surfaces of the CMU fragments. Moderate carbonation of the cement paste was also observed throughout the thickness of the fragments due to high void concentration. Carbonation was observed microscopically by observing thin sections cut at the exterior surface of the CMU fragments.

Photo 5 shows a photomicrograph of the carbonated cement paste between sand grains and entrapped air voids.

j) The average water-cementitious material ratio (w/cm), estimated from the optical examination, was approximately 0.40 ± 0.05. Based on the estimated w/cm (0.04) and the average volumetric proportion of paste (21%), the calculated cement content was approximately 5.3 sacks/yd3.

Painted Desert CC Petrified Forest National Park 6 KPFF Project No. 10022400221

Photo 5 – Photomicrograph showing the matrix for sample CMU-2. The center of the image is filled with carbonated cement paste with a feldspar sand grain at the left side of the image and a entrapped air void at the lower center portion of the image. Image taken at 100x magnification plane-polarized light (left) and cross-polarized light (right).

PART 5 – RILEM ABSORPTION TESTING

The two CMU fragments (CMU-1 and CMU-2) were tested for their resistance to water absorption.

The tests were conducted following procedures outlined by RILEM Commission 25, PEM, Test Method 1154. The fragments each consisted of approximately 26 in² of exterior facing and interior facing surface area. The exterior facing surface of each CMU fragment was assumed to be weathered while the interior facing surface was assumed to be the untreated formed original surface. A RILM Test Tube absorption test was conducted at the various surfaces to determine the masonry materials resistance to wind-driven rain and the masonry’s rate of moisture absorption.

There are several variations of the RILEM test, and a procedure outlined by Joseph L. Crissinger published in Interface Magazine (November 2005) was adopted for standardization. The graduated test tube was adhered directly to the surface of the CMU surfaces and distilled water was used to fill the test tube to the “0” point while a stopwatch was started. Readings were recorded every 5 minutes until 20 minutes had elapsed. Water was reintroduced at each reading if the entire column of water was previously absorbed. Photo 6 shows sample CMU-1 with the RILEM test tube installed at the exterior surface.

A total of six tests were conducted on the CMU fragment samples. Additionally, one test was conducted on a large area of mortar that was well adhered to sample CMU-1. After each test the samples were allowed to dry to a typical moisture condition prior to the next test. Water was immediately absorbed at both the exterior and interior surfaces of CMU-1. Water was observed moving through the voids at the opposing surface that was tested Results of the tests are shown in Table III. Photo 7 shows the exterior surface of CMU-1 during a test and a photo of the interior surface during the same test.

RILEM tests conducted on CMU-2 showed that the exterior surface was resistant to water absorption.

The interior surface reacted similarly to the tests conducted on CMU-1, however, several tests were

Painted Desert CC Petrified Forest National Park 7 KPFF Project No. 10022400221 conducted on CMU-2 exterior, away from foreign materials, and the rate of absorption was significantly lower.

Photos 8 and 9 show photomicrographs of the exterior surfaces of CMU-1 and CMU-2 respectively.

The samples look very similar on the exterior surface; however, there is a noticeable light gray cementitious material that infills voids and depressions of CMU-2. It is believed that CMU-2 was coated with a cementitious waterproofing material or densifier that is acting to reduce the absorption of water. Photo 10 was collected at lower magnification and shows an area of CMU-2 with higher concentration of the cementitious coating.

TABLE III – RILEM Test Tube Results

5 Mins 10 Mins 15 Mins 20 Mins

Test No.

Description Reading (mL)

Added (mL)

Reading (mL)

Added (mL)

Reading (mL)

Added (mL)

Reading (mL)

Added (mL)

1 CMU-1

Exterior

6 6 6 6 6 6 6 -

2 CMU-2

Interior

4 0 5.5 0 5.5 0 5.5 -

3 CMU-2

Exterior

0.3 0 0.5 0 0.5 0 0.75 -

4 CMU-2

Exterior

0 0 0 0 0 0 0 -

5 CMU-1

Exterior

6 0 6 0 6 0 6 -

6 CMU-1

Interior

6 0 6 0 6 0 6 -

7 CMU-1

Mortar

0.25 0 .5 0 .75 0 1 -

Painted Desert CC Petrified Forest National Park 8 KPFF Project No. 10022400221

Photo 6 – Photo showing a RILEM test tube installed at the exterior surface of sample CMU-1.

Photo 7 – Photo showing a RILEM test tube installed at the exterior surface of sample CMU-1 during test and the opposing surface during the same test with water observed moving through the void spaces of the sample.

Painted Desert CC Petrified Forest National Park 9 KPFF Project No. 10022400221

Photo 8 – Photomicrograph showing exterior surface of sample CMU-1.

40x magnification.

Photo 9 – Photomicrograph showing exterior surface of CMU-2. 40x magnification.

Painted Desert CC Petrified Forest National Park 10 KPFF Project No. 10022400221

Photo 10 – Photomicrograph showing exterior surface of CMU-2. 8x magnification.

CONCLUSIONS:

1) The mortar sample consisted of hydrated lime, portland cement paste and siliceous sand. An iron oxide pigment was evenly distributed at high concentrations throughout the mortar matrix.

2) The mortar represented by the sample was identified as a portland cement/hydrated lime mortar and has a composition that does not closely match standard mortars.

1.0 Portland Cement: 0.93 Hydrated Lime: 4.33 parts sand.

3) The CMU fragments were composed of portland cement paste with light-wight siliceous coarse aggregate and normal weight siliceous sand. An iron oxide pigment was present throughout the cementitious matrix giving the matrix a tan/red appearance.

4) The exterior and interior surface of CMU-1 allowed for a high degree of water absorption. The exterior surface of CMU-2 appeared to have a cementitious coating that limited water absorption.

5) No deleterious or secondary mineralization was observed in the mortar sample.

Sincerely, Tyler Jennison

Petrographer

Attachments: Appendix A, Appendix B

Appendix A Rinko and Associates Chemical Analysis

V & Assocr.A.TE9, LLc./ www.RrNKoLABs.coM

April4,2024

KPFF Structural Investigation Group 11 I SW Fifth Ave. Suite 2600 Portland, OR 97204-3628

Attn: Mr. Tyler Jennison Ref: Lab File # RA-0403-1A-24R Project: Petrified Forest National Park P.O. #10022400221

1. SAMPLES:

One (1) mortar sample for analysis;

2, ANALYSIS PERFORMED:

A. ASTM C1324-15- Examination and Analvsis of Hardened Masonry

Mortar

1961 E. Green Springs Rd. . Rescue, CA 95672 Tel (805)54&0105 Fax (530)69&6368 G e n e ral I n q u i ie s :i nfo@in kolab s. com

Robeft Haffner Lab Dircctor: Rh4inko@vahoo.com

Sample No. Sample ID Sample Description Sample weight, net (e)

Mortar 78.9

3: RESULTS:

A. ASTM C1324-f 5- Examination and Analysis of Hardened Masonry Mortar

Sample: Mortar, Project: Petrified Forest National Park, P.O. #10022400221

Parameter/Comoonent

1. Soluble Silica, % (Ww)

2. Calcium Oxide ,% (wlw)

3. Magnesium Oxide, % (w/w)

4. Insoluble Residue, % (ilw)

5. Loss on Ignition, o% to 110"C (wlw) I i0oC to 550"C (ilw) 550oC to 950'c (wiw)

Calculated:

6. Portland Cement, % (wlw)

7. Hydrated Lime, % (w/w)

8. Sand, % (dw)

Result

2.97 13.22 0.04

52.09

2.45 't.67

9.15

14.14 5.58 s2.09

9. Portland Cement: Hydrated Lime: Sand Ratios , (volumetric proportions) 1.0:0.93:4.33.

*conlaiDs iron oxide pigmentation aI level ol 6 % w and is included in thc catculations

Appendix B Terracon Sand Gradation Results

Last Page

PARTICLE SIZE DISTRIBUTION REPORT

Report Number:

Service Date:

Report Date:

Task:

Client

82221239.0130

04/02/24

04/09/24

10022400221- Painted Desert CC Mortar Analysis

KPFF Consulting Engineers

Attn: Tyler Jennison

111 SW 5th Ave

Ste 2500

Portland, OR 97204

700 NE 55th Ave

Portland, OR 97213-3150

503-659-3281

#KPFF Laboratory Testing 2022-2024

700 NE 55th Avenue

Portland, OR 97213

Project

Project Number: 82221239

Mortar Petro SandSample Description:

Petrified National Forest ParkSample Location:

Sample Information Laboratory Test Data

ASTM C136Test Method:

NAMethod:

Atterberg Limits:

Sample Type:

Sample Preparation:

Sieving Method: Single Sieve-Set Sieving

Percent Finer

Pass (X=Fail)

Sieve Size

Spec.*

#4 100

#8 93

#10 92

#16 81

#20 73

#30 64

#40 51

#50 36

#60 26

#100 10

#140 5

#200 2

D = D = D = C = C = 60 30 10 c u

FM = 0.52 0.27 0.151 0.9 3.5

Comments: Sample was tested in accordance with ASTM C136; due to the nature of the sample, the amount tested was below the minimum specified in ASTM C136, Section 7.3.

Services: Perform all necessary testing on aggregate received by laboratory to determine conformance with a provided specification.

Reported To:

Contractor:

Report Distribution:

(1) KPFF Consulting Engineers, Tyler Jennison

(1) KPFF Consulting Engineers, William Harding Trevor Tickner

Laboratory Supervisor

Reviewed By:

Terracon Rep.: Derrick Powlison

Test Methods:

The tests were performed in general accordance with applicable ASTM, AASHTO, or DOT test methods. This report is exclusively for the use of the client indicated above and shall not be reproduced except in full without the written consent of our company. Test results transmitted herein are only applicable to the actual samples tested at the location(s) referenced and are not necessarily indicative of the properties of other apparently similar or identical materials.

CR0027, 06-10-17, Rev.0