100 Percent Expansion Joint Assessment_CAV.pdf

DEPARTMENT OF VETERANS AFFAIRS

AUDIE L. MURPHY MEMORIAL VETERANS HOSPITAL

STRUCTURAL REVIEW OF EMPLOYEE

PARKING GARAGE EXPANSION JOINT

San Antonio, TX November 6, 2020

Barker Structural #215549C

PARKING GARAGE VIEWED FROM THE NORTH

Prepared by:

Kris Barker, P.E.

Principal

Barker Structural 4040 Broadway

Ste. 604 San Antonio, TX 78209

Texas Firm #EF6676

1.0 PROJECT INFORMATION

Phase I o 4 levels (3 elevated) o Precast concrete with cast-in-place concrete topping (2 ½” thick topping except at garage perimeter) o Built in or about 2012 o Drilled concrete pier and grade beam foundation

Phase 2 o 5 levels (4 elevated) o Precast concrete with cast-in-place concrete topping (2 ½” thick except at garage perimeter) o Built in or about 2014 o Drilled concrete pier and grade beam foundation

2.0 SCOPE OF SERVICES (problem definition)

The expansion joint between the 1st and 2nd phases, at the 2nd level, has cracked and spalled. The photo below was taken at the 2nd level entrance lane. The scope of this report is as follows:

Visual Observations – Barker Structural visited the parking garage on August 4, 2020 to review the extent of the deterioration. We returned again on October 20, 2020 to assist with the concrete coring.

Review of Available Data – The original structural plans for both phases were made available for Barker Structural’s review related to the expansion joint.

3.0 LIMITATIONS

The intent of this report is to provide a general understanding of the condition of the structure at the expansion joint at each level. As the reinforcing and embedded items were not exposed, this report cannot be considered a comprehensive summary of structural deficiencies.

4.0 SUMMARY AT EACH LEVEL

A. 1ST Level (foundation) – not part of this review.

B. 2nd Level

As this report will indicate, the damage at the expansion joint appears to be limited to the entry lane at the 2nd Level.

The Phase 1 and Phase 2 structural plans specify 2 ½” minimum concrete topping.

As the Phase 2 expansion joint detail (shown above) indicates, the structural engineer anticipated that both slabs would be of equal thickness. The photo below depicts the actual condition. The Phase 2 tee flange ended up higher than the Phase 1 flange by approximately 2” or slightly more.

The detail and the photo are viewed looking north. Phase 1 is to the right side of the joint.

The Phase 2 contractor reduced the Phase 2 topping thickness to as thin as 1 5/8”, apparently to flush the new topping with the existing topping.

The 2nd floor inherently receives more vehicle traffic than do the levels above. The 1 5/8” thickness robbed the joint of strength and toughness. The cracks and spalling are the result.

C. 3rd Level

Since the topping thickness at Level 2 is substantially less than was specified we requested that the topping be cored at all 3 elevated floors (2nd, 3rd and 4th).

The 3rd Level cores indicate that the topping in the vicinity of the expansion joint is approximately 2 1/8” thick.

The expansion joint appears to be intact. There is no noticeable cracking or spalling.

As the photo to the right indicates, the adjacent concrete curb has been damaged. We don’t know the cause. It is not indicative of a structural concern with the garage. However, we will recommend that it be repaired.

D. 4th Level

The 4th Level cores indicate a topping thickness of approximately 2 1/8”. I did not observed any cracking or spalling at the 4th Level.

5.0 CONCLUSIONS AND RECOMMENDATIONS

2nd Level o That a strip of topping approximately 4’-8” wide be removed from each side of the expansion joint and replaced. Since the inbound and outbound lanes are both significantly thinner than was specified, we recommend that the topping be removed and replaced at both lanes.

o That the expansion joint material also be removed and replaced across both lanes.

3rd Level o Even though the topping at Level 3 measures less than the specified 2 ½” we do not recommend it’s removal and replacement. The joint at this level appears to be performing adequately. In years past 2” thick topping was common. That thickness performed well. For other reasons (code upgrades) we now thicken topping slabs to 3 ½” or 4” but removing and thickening the topping at an existing joint that is performing well, in our opinion, would not be prudent.

o We recommend that the concrete curb be removed and replaced.

4th Level – Similar to Level 3, the existing expansion joint appears to be performing adequately. In our opinion remedial action is not necessary at the 4th level.

6.0 GENERAL COMMENTS

This report has been prepared for the exclusive use of our client, for specific application to the project discussed and was prepared in accordance with generally accepted consulting engineering practices. No warranties, either expressed or implied, are intended or made. In the event that additional information becomes available, the conclusions and recommendations contained in this report shall not be considered valid unless Barker Structural reviews the additional information and either verifies or modifies the conclusions of this report in writing.