Disney Frontierland Expansion Wins the Decorative Concrete Council’s Award for Cast-in-Place Special Finishes Over 5,000SF

The Decorative Concrete Council awarded the Disney Frontierland Expansion project the “Cast in Place Special Finishes Over 5,000SF” this week in a virtual ceremony. The goal of this project was to prepare the Disneyland park for the new Star Wars attraction. In addition to four tunnels, multiple retaining walls and a marina, Largo’s scope included a concrete trestle bridge for the railroad at the Rivers of America attraction. Although the visual aspect of the end product is exquisite, the details that were put into the fabrication of the two elements of the structure; the columns and hammerheads, and the concrete mix design used to simulate an aged wooden railroad trestle bridge, is also noteworthy.

The columns started in the back lots of Walt Disney Imagineering as an image in the mind of the design team. This image was transformed into approximately 50 lineal feet of hand carved foam positive. This was reviewed by the Disney team to confirm their vision and sent out to Fitzgerald Formliners to confirm that the positive would produce a usable form liner. A number of changes were made in the foam positive to ensure that no negative spaces existed in the positive to allow for smooth removal of the form liner. To allow for proper alignment of the four columns that attached to each of the twelve hammerheads, relative to each other, the column forms were fastened to a wall form.

With all of the details in the form liner, Largo contacted Holliday to discuss the appropriate concrete mix design to ensure a perfect positive from the very detailed form liner. Although self-consolidating concrete is not frequently used in the Southern California market, it was determined that with the details, the importance of exact alignment of the columns and the limited space within the column form to allow for a vibrator, that this would be the appropriate mix design to yield the best finished product.

4000 psi @ 28 days Self Consolidating Concrete mix with a water to cement ratio of 0.44. The cementitious content was 8.5 sacks that was 70% Type II/V cement and 30% Type F Fly Ash. Nominal spread was 25” to 30” but it was usually in excess of 27”. It has a maximum aggregate size of 3/8”, but since the mix needed to reveal very fine details it was proportioned to contain 70% Washed Concrete Sand. All of the aggregates are from Holliday Rocks Upland California Facilities. The admixtures in the mix design included: a Type F High Range Water Reducing Superplastizing polycarboxylate, a workability-retaining admixture that provides flexible degrees of slump retention without retardation. And when needed (in this case it wasn’t but was always available) a viscosity-modifying admixture that is specially developed for producing concrete with enhanced viscosity and controlled rheological properties that increases resistance to segregation while facilitating placement and consolidation.

The hammerheads that span across the columns were formed out of rough sawn dimensional lumber of varying widths on top of the above-mentioned columns. Each of the twelve hammerheads were formed with no common joint plan of the rough sawn lumber. Steps were taken to raise the texture of the rough sawn lumber. Each board was soaked in water overnight and sealed with form release to accentuate the rough sawn look to the vision of the Imagineers. The hammerheads were also poured with the self-consolidating concrete mix design that was used in the columns.   Typically, these decorative types of concrete elements are a post installed façade covering a structural column, but with the load requirements of the train, envisioned size of the elements and the environmental concerns of the river, the above summarized use of concrete was developed and put to use.

Reach for the Stars!

The New Century Plaza Towers became the tallest buildings in Century City, CA this month when Largo Concrete topped out at level 46. In addition to constructing the twin towers simultaneously, Largo also retrofitted the historic Fairmont Hotel designed by world-renowned architect Minoru Yamasaki along Avenue of the Stars. Yamasaki was also responsible for the triangular shaped 44-story Century Plaza Office Towers located on the opposite side of the main thoroughfare. In an effort to pay homage to Yamasaki, design architect Pei Cobb Freed & Partners shaped the new towers as reuleaux triangles. A figure consisting of three circular arches, formed from the intersection of three circular disks, each having its center on the boundary of the other two.

Largo began construction during the summer of 2018 by pouring seven large mat foundations, two of which were we over 9,300CY. Limited access to the site meant much of the readymix for the large pours had to be piped in from Constellation Way to placing booms mounted on tower crane foundations. The first of these two pours utilized five truck mounted boom pumps and two placing booms to place 9,509CY over the course of 16 hours. The second large pour was even further from the street and required five placing booms and two boom pumps to place 9,367CY over 16 hours.

The first four levels out of the ground are dedicated primarily to 1,345 parking stalls and back-of-house facilities. Radius vehicular ramps and grand staircases exude the circles used to shape the reuleaux tower decks to come above. A 25’ tall radius transfer beam supports 30 columns opening up the loading dock space. Formwork supplier Peri USA assembled a temporary access bridge to deliver rebar from Constellation Way to the back of the site. In addition to reducing the amount of crane time the temporary bridge also minimized vehicular traffic along the privately owned Solar Way.

The twin towers rise from the exquisitely landscaped plaza level lined with retail shops and cafés for a pedestrian experience which continues through the hotel lobby to Avenue of the Stars. The towers were constructed concurrently with crews pouring a deck on alternate towers every two days. A custom PERI ACS 400 core wall, self-climbing interior system with gantry beams suspending the exterior formwork was used for the hexagonal-shaped core walls. A radius trolley trailer beam was suspended from the core climber to facilitate construction of the steel framing inside the tower lobbies. The entire system weighed over 360,000lbs.

A column mounted cocoon screen with attached roll-back column formwork enclosed the upper floors as they were being constructed which removed re-shoring and enhanced safety on the site. The perimeter column forms were designed so that they could be stripped horizontally, from underneath the deck, which allowed the deck formwork to be completed before the column forms were poured and stripped. Largo also self-formed the masonry scope of work placing 102,000 concrete masonry units throughout the building including the entire height of the core.

In an effort to ease the strain on vertical transportation between the two towers, teams utilized a temporary 60’ pedestrian bridge spanning the two structures beginning at level 30 and moving up to level 43 as the buildings progressed. This proved especially helpful once Covid-19 reduced the number of individuals in each manlift for social distancing measures.

When complete, the $2.5 billion revitalization project will be over 1 million square feet on the 6.13-acre site. The Fairmont Century Plaza will feature 400 hotel suites with 63 private residences on the upper levels and the towers will hold 290 luxury condominiums with multi-level penthouses. Largo Concrete will have worked 760,000 Man Hours placing 151,000 CY of Concrete! General contractor Webcor is working with Gensler and Harley Ellis Devereaux Architects and structural engineer Englekirk to have the development open during the summer of 2021.

Uptown Whittier Parking Structure Tops Out

Largo recently topped out at the Uptown Parking Structure in Whittier, CA. The project is located on the east side of Comstock Avenue between Bailey and Philadelphia Street. The structure is being built to support the vibrant downtown commercial and entertainment area along Greenleaf Avenue.

Standing four levels above grade, the structure holds 351 parking stalls across 122,083gsf. The facade along Comstock was designed to compliment the Uptown architecture utilizing plaster, exterior insulation finishing systems (EIFS) and red brick to achieve the desired look. The elevator cores on either side of the building are structural steel with metal stud framing and brick veneer. The stairs along Comstock are cast-in-place while the stairs in the back of the building are steel.

Largo is the general contractor for this project self-performing the concrete formwork, pumping, place and finish, and masonry scopes of work. Largo is working for the City of Whittier to have the structure open before the end of the 2020.

Yerba Buena Island Condominiums Top Out

Largo Concrete poured the last concrete deck at the Yerba Buena Island Condominiums this month. The project is perched on the small island in the San Francisco Bay best know for its tunnel connecting the two spans of the Bay Bridge. The development begins at the corner of Macalla and North Gate Roads on the northeast side of the island and works it’s way up the hill. The structure is 257,380gsf with 2.5 levels of below grade podium parking and five levels of light gauge metal stud above it. Largo worked with DCI Engineers to deliver the superstructure in a design-build format. Tenants will enjoy views of the self-anchored suspension eastern span of the Bay Bridge with Oakland and Emeryville in the background to the east, and Treasure Island to the north. General contractor Cahill Contractors are BDE Architecture aim to have the development open in early 2021.

Le Conté Apartments becomes UCLA’s Tallest Building

Largo Concrete topped out at the UCLA Le Conté Apartments this summer making it the tallest building on campus. The undergraduate student housing project is located at the corner of Le Conte and Gayley Avenue on the south side of the campus. The south building is 11 cast-in-place levels above grade and the north is 19. The overall project is 301,761gsf and will add 1,167 beds in 192 rooms. General contractor PCL Construction, Studios Architecture and Nabih Yousseff & Associates structural engineers are on track for temporary occupancy in the Winter of 2021.

Largest Column-Free Space in North America Pours Out at the Las Vegas Convention Center

Largo recently poured-out at the Las Vegas Convention Center (LVCC) Phase 2 Expansion project which features 328,000sf of column-free exhibit space. The 1.44m gsf addition includes a total of 600,000sf of exhibit space, 210,000sf of pre-function areas and 150,000sf of meeting and multi-purpose space. 195,000sf of support areas include MEP facilities, restrooms, public corridors, and a central utility plant. 280,000sf of service space includes loading docks, kitchens, food and beverage outlets, security stations, and office space for admin, maintenance and operations staff.

Largo placed over 70,000CY of concrete across 970,000sf of slab-on-grade, 243,000sf of suspended decks and beams and 414,000sf of slab on metal deck. Largo placed concrete on 296 different days averaging 235CY per pour! The majority of the 585,000sf Exhibit Hall Floor was placed in 88 working days, which averages out to placing 6,600sf every day for four months! General contractor Martin Harris/Turner Construction, JV, TVS Nevada Architects and Magnusson Klemencic Associates structural engineers, the development is scheduled to be complete in December 2020.

Miro Towers Become the Tallest Buildings in San Jose

The Miro Towers became San Jose’s tallest structures this month when Largo poured level 29 at 291′ above street level! Located on the north side of E. Santa Clara Avenue between Fourth and Fifth, the buildings are across the street from City Hall which used to be the city’s second tallest structure. Miro will feature a total of 630 two and three bedroom units and 633 parking spaces.

Stressing Procedure

Transfer girders utilize four rows of post-tensioned cables which are progressively stressed throughout construction. The girders are located on level five above grade and are up to 72” wide by 64” deep! The additional rows of PT cables are spaced 6” apart and lay below a row of tendons which are stressed after placing level five. Upon completion of level ten the bottommost row is stressed, then the second from the bottom row is tensioned at level 15, ending at level 25.

Steinberg Hart Architects, DCI Structural Engineers, and general contractor Suffolk Construction are on schedule to have the Miro towers open early 2021.

4 Diller Tops Out Along El Camino Real in Redwood City, CA

Largo topped out at the 4 Diller project in Redwood City, CA this month! The 555,736gsf building is located in the heart of Silicon Valley and 35 of the 350 total units are designated as for affordable housing. The development has three levels of below grade parking which houses 441 private vehicles and 89 bikes. In addition to 2,900sf of retail space at street level the development features a fitness room, a club room and rooftop pool deck. General contractor and developer Greystar, Studio T Sqaure Architects and structural engineer Cary Kopczynski & Company aim to have the development open late 2020.

Fig-Pico Hotel Mat Foundation Pour

Largo poured the massive mat foundation for a new high-rise tower in downtown Los Angeles on Saturday night. Located on the northeast corner of Figueroa and Pico, the hospitality development will add 727 rooms when complete in 2022.

National Readymix began service to the site at 1AM, and it took 7 pumps nearly 11 hours to pour 7,096CY.

The building will consist of 37 total levels which includes a concrete roof. Building services are located in the basement with 11,000sf of retail space on street level. Six levels of above grade parking followed by a pool deck with outdoor restaurant space make up the first eight levels. Hospitality levels are shared between the AC and Moxy Hotel brand names with 347 and 380 keys respectively. Largo Concrete is working with Lightstone developers, general contractor Suffolk Construction, Gensler architects and Saiful Bouquet structural engineers to be poured out in late 2021.

Mat Foundation Pour Time-Lapse Video

UCLA Margo Leavin Art Studio Wins Charles Pankow Award

Largo Concrete worked with Abbott Construction on the UCLA Warner Graduate Art Studio Project in Culver City, CA.

The overall project consisted of a 21,200sf renovation of the Graduate Art Studios existing building and a 26,800sf, L-shaped addition to the facility. Design by architecture firm Johnston Marklee, the building is organized in the fashion of a ‘community’ with small blocks of private studios in a cul-de-sac setting adjacent to communal, plaza like facilities connected by pathways akin to city streets. Specialized lab space for woodworking and ceramics are also included in the facility which is designed to be adaptable to accommodate future new technologies and working methods. The Margo Leavin Art Studio project anticipates a LEED Gold Certification.

The construction of this building utilized several different concrete assemblies to support the building and achieve the natural concrete look. This was especially important to designers and the University to integrate the facility into the former industrial zone know as the Hayden Tract. The exterior walls were designed as concrete tilt-up panels with 2′-0″ “pillows” or half-circles on the exterior face. Special single-use form liners were designed and fabricated out of state to achieve the “pillow” shapes. Cast-in-place stitch columns were used to connect the tilt panels at each grid line. The stitch columns also used the “pillow-shaped” form liner but were exceptionally challenging because they were poured full-height (28′-10″) between the panels and had to line up perfectly with no gaps or visible seams. Largo Concrete’s in-house engineering team designed custom falsework to support lintel panels which would eventually be suspended 15’-0” in the air. These panels also feature the “pillowed” exterior finish and are unsupported from below as they span the openings to the building.

The interior frame of the building consists of cast-in-place walls, columns and ring beams: all exposed with an “as-cast” finish. Shotcrete walls and beams were installed against the existing building walls on two sides to connect the new construction to the existing building. As was the case with the exterior finish, no sacking or other cosmetic enhancements were allowed on the interior as well. The buildings roof is designed as a grid of vaults with curved glulam beams covered by roofing membrane, curved polycarbonate or nothing at all to allow for natural ventilation in certain spaces.

Limited access to the building pad because of the existing structure made it difficult to form, place and hoist the tilt-up panels. The time frame to complete all of the building concrete was 8 months. Despite these challenges the concrete scope of work was completed in eight months with zero safety incidents over 29,213 hours. Some of the potential hazards that were endured included 30’-0” shotcrete walls and beams, 30’-0” shear walls and columns, 30’-0” tilt-up panels and hoisting the panels with a high voltage wire running along one side of the jobsite.

A special thanks to all those involved in this great project:
Owner: University of California, Los Angeles
General Contractor: Abbott Construction
Architect: Johnston Marklee
Structural Engineer: Simpson, Gumpertz & Heger
Readymix Supplier: Cemex