Oregon Zoo, Elephant Lands - Shotcrete

Portland, OR

Technical Information Project Completion Date: November 2, 2015

Project Location: Portland, OR

Size of Project: The Exhibitory scope of work at the Asian Elephant Oregon Zoo Project required 1,260 cubic yars of shotcrete placed concrete. This included a 7,000 square foot main pool, 1,400 square foot splash pool, 9,500 square foot of artistically textured shotcrete soil nail wall, and 4,000 square foot of artificial shotcrete boulders.

Concrete Strength Requirements: 4,000 psi in 27 day duration.

Water/Cement Ratios: A maximum water-to-cement ratio of 0.45 for all walls on the project. At the main pool floor/slab a maximum water cement ratio of 0.39 was required. This consists of 200 cubic yards of material at pool floor.

Unique or High Volume Admixtures: Integral waterproofing admixture xpex 500 was added to all pool concrete. Davis Integral color was added to all exposed finished concrete.

Oregon Zoo, Elephant Lands - Shotcrete

Unique Mix Designs: A total of four mix designs were required for the exhibitory structures. Two were composed to accommodate waterproof structures. The other two mix designs allowed for shotcrete placement and artistic shaping/carving of the finished product.

Unique Specifications/Requirements: Integral waterproofing additive was specified and included in two mix designs required at the pool structures. Two separate mix designs were designed for placement methods at the Main pool. Integral Davis color was included in two separate shotcrete mix designs in order to accomplish natural organic aesthetics at the finished shotcrete walls.

Placement Challenges or Unique Techniques: In collaboration with the general contractor, staging and job site access was a daily challenge we worked together to overcome. Shotcrete was utilized on this project in order to accomplish monolithic pool installation, top down soil nail shoring structures and artistically carved artificial boulders.

Other Special Technical Aspects: One sided forms, neat cut top down excavation, MSE wall structures, and level pathways were a few of the many subgrades in which shotcrete was applied. Reinforcing was artistically shaped in order to accomplish organic natural like structures to be installed with shotcrete and carved to create the natural elephant habitat.

Oregon Zoo, Elephant Lands - Shotcrete

Oregon Zoo, Elephant Lands - Shotcrete

Elephant lands is a state of the art exhibit in which 3.6 acres of the Oregon Zoo is dedicated to the health and wellbeing of the entire elephant family.

Oregon Zoo, Elephant Lands - Shotcrete

Artistically crafted concrete structures such as containment walls, pools, and feeders promote animal enrichment and allow elephants to be active throughout the entire day.

Oregon Zoo, Elephant Lands - Shotcrete

The scope of this project was a design build construction based bid. Preliminary designs were provided by CLR Architects and Turnstone Construction worked closely with both the design

team and animal management to accomplish an ideal living situation for the elephants.

Oregon Zoo, Elephant Lands - Shotcrete

Top down shoring methods were used throughout the project to

create structures for hillside retainage and animal containment.

Oregon Zoo, Elephant Lands - Shotcrete

Soil nails were drilled horizontally into the hillside excavation and were grouted and shotcreted in four to six foot lifts.

Oregon Zoo, Elephant Lands - Shotcrete

Once the permanent shoring walls were completed, shotcrete was applied for a second coat and artistically textured to simulate natural cut bank cliffs.

Oregon Zoo, Elephant Lands - Shotcrete

A big portion of the project included a 160,000 gallon Main Pool and also a small wade pool. Turnstone worked with CEMEX Ready Mix to develop both a 5,000psi concrete mix for the pool floor as well as a 5,000psi shotcrete mix

for the pool walls. Both mix designs included integral waterproofing admixture Xpex as well as 15% minimum of fly ash.

Oregon Zoo, Elephant Lands - Shotcrete

The pool shell structure was placed in two pours. The pool floor was boom pump placed for a total of 200 cubic yards, then the pool walls

were placed via the shotcrete method at one-sided forms.

Oregon Zoo, Elephant Lands - Shotcrete

Simulated concrete boulders were sculpted throughout the project as aesthetically pleasing facades to hide manmade structures such as

walls, skimmer boxes, and bollard posts.