Encl 4 Exist Materials Testing Report dated April 20 2021.pdf

April 20, 2021 Project No.: 1210197C

Mr. Nathan Cannon

DAVENERGY SOLUTIONS

2207 Garnet Avenue, Suite 1

San Diego, CA 92109 Email: Nathan.Cannon@davenergy.com

Subject: SOW Police Annex – Materials Testing + Investigation

Project No: 640-382

795 Willow Road, Menlo Park CA

Dear Mr. Cannon:

As requested, Applied Materials & Engineering, Inc. (AME) has completed testing and investigation of the existing reinforced concrete footing/slab and the structural steel members at the subject project.

BACKGROUND

The location is a construction project that has been halted. Concrete slabs and footings were constructed to support future structures. There are steel beams and posts stored adjacent to the concrete foundation/slab to be used in future construction of the main structure.

Photo 1 is an overall shot of the site, showing the constructed slab pad. Photo 2 shows the structural steel beams and posts that all laying on the soil adjusted to the slab.

OBJECTIVE

The objective of this evaluation is to test the concrete footing/slab for compressive strength, evaluate the slab rebar, steel posts and beams for corrosion, verify the size of footings and installation of rebar;

all these should be in accordance to drawings provided to us. The drawings were produced by

Polytech Associates Inc. San Francisco, dated October 8, 2013.

The verification will include opening of specified areas to allow for measurements of the constructed footings and sampling of materials to be tested in our laboratory.

PROCEDURES & RESULTS FOR MATERIALS TESTING

1. Concrete Cores Compressive Strength Testing

A total of three (3) concrete cores (C1 through C3) were removed from the perimeter of the concrete footing/slab for compressive strength testing. Locations of removed samples are shown in Figure 1.

Photo 3 shows the cores removed.

SOW Police Annex – Materials Testing + Investigation

April 20, 2021

Compressive strength testing was carried out per ASTM C42 (dry). Results of the compressive strength testing are shown in Table I; the average compressive strength of the concrete is 8460 psi.

The specified strength of the concrete is 4000 psi (Note IV - 6 in Drawing No: SS001) at the foundation and slab. The test indicates the concrete meets that specified requirement.

2. Reinforcing Steel (Rebar) Tensile Testing from CMU Slab Dowels

A total of two (2) slab dowel rebar samples (R1 and R2) were removed randomly and tested for tensile properties per ASTM A370. Photo 4 shows the dowels removed.

Results of the tensile properties testing are shown in Table II.

The specified strength of the rebar is 60 ksi (Note IV - 1 in Drawing No: SS001). The test indicates

(fy of 71.6 ksi and 75.2 ksi) that the dowel rebar meets that specified requirement.

3. Posts and Beams Tensile Testing

A total of Four (4) steel coupons were removed and tested, two (2) from the HSS 8 x 8 x 5/16 posts

(P1 & P2), one (1) from a W18x35 beam (B1) and one (1) from a W24x55 beam (B2). The coupons were removed from the posts and (the web of the) beams laying on the ground adjacent to the concrete slab. Photo 5 shows the test coupons removed.

Results of our tensile strength testing are shown in Table III.

The specified strength of the beams is ASTM A992, Grade 50 and of the HSS ASTM A500 Grade B

(Note VII in Drawing No: SS001). The test indicates (fy of 57.0 ksi, 60.3 ksi, 56.5 ksi and 57.7 ksi) that the structural steel meets the specified requirement.

4. Corrosion Testing of Posts, Beam and Rebar

A total of six (6) samples (4 steel coupons and 2 rebar samples) were tested for corrosion (loss of metal) to determine if significant metal loss had occurred due to rusting; these are the same samples described above, under 2. and 3. Photo 6 shows a cross-section of the W18 x 35 beam coupon and amount of corrosion and Photo 7 shows a cross-section of the W24 x 55 coupon and amount of corrosion.

Results of our testing are shown in Table IV. The average loss of metal (corrosion) of the beams, posts and rebar are 5.4%, 6.0% and 6.9%, respectively.

Generally accepted practices (based on accepted structural engineering principals) require that metal loss be not greater than 10% for the steel to be acceptable. Since all the average measurements were less than 10%, the steel members are acceptable for future use.

*These members will need to have the corrosion removed prior to being put to final use.

SOW Police Annex – Materials Testing + Investigation

April 20, 2021

CONSTRUCTION OBSERVATIONS AND RESULTS

1. Slab on Grade (S.O.G)

GPR (ground penetrating radar) was used to survey the slab and an exposure was made to investigate the reinforcing of the slab and slab thickness.

It was determined that #4 rebar has been installed at 18" o.c. (as shown in Photo 8) and the slab was 5" in thickness, in accordance to the key note in Drawing No: SF201A. The findings meet that specified requirement.

2. Footings

a) Demolition of the slab and excavations (A1 & A2) was performed to allow for confirmation of the width and depth of the footing and scanning of the foundation for rebar installation.

Location of investigated slab, excavation and scannings are provided in Figure 1 (A1 & A2).

Excavation and location A2 is shown in Photo 9.

b) We determined that #5 rebar bottom reinforcing was found to be installed longitudinally (as shown in Photo 10) in the footing. The depths and widths of the footings are in accordance to

Detail 16 and footing schedule 19 on Drawing No: S1401. The footing at A1 was found to be

2' - 0" x 1' - 6". The continuous footing at A2 was found to be 1' - 6" x 1' - 6"; this meets the requirement of Figure 1 on the framing.

c) At location A2: #5 @ 24" is correct per the plans, Detail 8/S1701 (8" CMU). Dowels to match wall reinforcing. At location A1: 12" CMU, dowels are #5 @ 24" o.c.

3. Structural Steel Beams and HSS Posts (Columns)

The number of wide flange beams and HSS posts was tallied and compared to those required on the roof plan.

All structural steel beams and HSS posts have been accounted for and are stored under tarps adjacent to the concrete slab (the lengths and of the beams and columns have not been confirmed). The base templates for the posts have been installed.

SUMMARY OF FINDINGS

1. The concrete compressive strength meets the plans & specification.

2. The reinforcing steel meets the plans & specification.

3. The structural steel meets the plans & specification.

4. The corrosion of the metals is within industry standards.

5. The S.O.G. meets the plans & specification.

6. The footing excavated meets the plans & specification.

7. The spacing of the dowels for CMU construction meet the plans & specification.

TABLE I

CONCRETE CORE COMPRESSIVE STRENGTH

SOW Police Annex

795 Willow Rd. Menlo Park, CA

AME Project No. 1210197C

*See Figure 1 for approximate test locations.

Core

ID*

Element

Location

As

Received

Height

(in.)

Diameter

(in.)

Capped

Height

(in.)

Area

(in.²)

Correction

Factor

Ultimate

Load

(lbs)

Ultimate

Compressive

Strength

(psi)

C1 Perimeter foundation

6.38 2.77 5.46 6.02 1.000 51,180 8500

C2 Perimeter foundation

6.23 2.77 5.40

6.02

1.000 47,310 7850

C3 Perimeter foundation

6.32 2.77 5.36

6.02

0.995 54,730 9040

Average 8460

TABLE II

DOWEL REINFORCING STEEL TENSILE STRENGTH TEST RESULTS

Steel Sample ID R1 R2

Bar Size #5 #6

Diameter, inch i 0.335 0.504

Actual Area, sq. inch

0.099 0.200

Yield Point, lbs.

7,080 15,001

Maximum Load, lbs.

11,000 23,666

Yield Strength, psi 71,587 75,193

Tensile strength, psi 111,223 118,627

Elongation in 2", inch

2.34 2.42

Elongation %

17 21

TABLE III

STEEL POST AND BEAM TENSILE STRENGTH TEST RESULTS

Steel Sample ID B1

(beam)

B2

(beam)

P1

(post)

P2

(post)

Width, inch 0.474 0.505 0.495 0.481

Size Depth, inch 0.302 0.368 0.307 0.306

Actual Area, sq. inch

0.143 0.186 0.152 0.147

Yield Point, lbs.

8,163 11,203 8,612 8,479

Maximum Load, lbs.

10,251 14,804 9,878 10,167

Yield Strength, psi 57,084 60,296 56,595 57,680

Tensile strength, psi 71,685 79,677 65,030 69,163

Elongation in 2", inch

2.6 2.65 2.62 2.63

Elongation, %

30 36 31 32

TABLE IV

STEEL POSTS AND BEAMS CORROSION TEST RESULTS

Steel Sample ID B1

(beam)

B2

(beam)

P1

(post)

P2

(post)

R1

(bar)

R2

(bar)

Specification Dimension (in.) 0.300 0.3950 5/16 5/16 0.625 0.750

Average Actual Measurement (in.) 0.2960 0.3577 0.2864 0.2984 0.583 0.697

Percentage of Corrosion (%) 1.3 9.4 7.4 4.5 6.7 7.1

Average Corrosion (%) 5.4 6.0 6.9

Figure 1. Foundation plan showing locations of core samples and footing excavations.

Photo 1. Overall view of the concrete slab (S.O.G.) – the upright bars are the CMU dowels.

Photo 2. The structural steel beam and posts laying on the grass – they are covered

With tarps.

Photo 3. Concrete core samples removed from locations C1 through C3 noted on

Figure 1.

Photo 4. Two dowel rebar samples removed.

Photo 5. Post and beams coupons samples removed from steel framing members lying on the ground adjacent to the slabs.

Photo 6. Cut section of the W18 x 35 beam.

Photo 7. Cut section of the W24 x 55 beam.

Photo 8. Example of exposed #4 rebar 18" o.c. at A1 in Figure 1 above. This area was further excavated to confirm the dimensions of the foundation and the footing was scanned for rebar location which was located in accordance to Detail 16 and footing schedule 19 on Drawing No: S1401.

Photo 9. Excavation at A2 where the foundation dimensions were confirmed and the footing rebar locations were confirmed.

Photo 10. Excavation at A2 where the foundation dimensions were confirmed and the footing rebar locations were confirmed.