Concrete package for the San Francisco 49ers stadium
49ers Stadium
A joint venture between Turner Construction and Devcon Construction has awarded the concrete package to Conco for the $1.2 billion San Francisco 49ers stadium. Designed by architect HNTB, the stadium is scheduled to open in time for the 2014 NFL season.
The project consists of slabs in excess of 2,000,000 square feet and will use more than 65,000 cubic yards of concrete. In order to meet the demands of the ambitious timeline for completion of the foundation, Conco will be working in four separate areas simultaneously. The same approach will be taken for the many deck pours that will need to be completed.
Conco brings to the project its vast experience in public arenas. Among its portfolio of projects include all the cast in place concrete for the San Francisco Giants ballpark (AT & T Park), the foundation package for the HP Pavilion (Shark Tank), all cast in place concrete for the LA Live complex, and ancillary structures for the Seattle Seahawks Stadium.
Visit the Construction Camera page for a live view of the construction.
Wafflemat is one of the most-proven foundation systems ever developed, with millions of square feet of residential and light commercial space built across the United States and Mexico since 1995 – all without a single structural failure.
It is also one of the easiest, and in terms of cycletime, fastest to construct, taking 3 – 4 days vs. 10 – 14 for alternative slabs. Wafflemat conforms to both International Building Code and Post Tension Institute specifications.
To build a Wafflemat foundation, all that’s needed is a clean and level pad, as the system sits directly on grade. No pre-soaking is necessary.
After installing underground utilities, a task made much easier with Wafflemat because the trenching does not have to go under any in-ground ribs or deepened footings, the perimeter formwork is placed directly on the pad.
A series of interlocking Waffleboxes, 8½” or 12” high, 19” x 19” thermal-grade, heat-resistant, patented plastic forms, are then set directly on the ground. Strong enough to walk on, they connect together at the top and bottom with plastic clips supplied with the Wafflemat system and create voids in the foundation. There is only one way Waffleboxes can be installed, ensuring each Wafflemat foundation is laid out correctly – and, to code.
A post tensioned or rebar reinforced concrete slab, usually 4” – 5” thick, is monolithically poured directly over the Waffleboxes. The pour creates concrete beams running throughout the footprint and perimeter. The completed Wafflemat slab then sits on the ground like a raft.
There are two key features that set Wafflemat apart from all other foundations systems, and are the reasons why it delivers superior performance. First, the voids formed by the Waffleboxes act as ‘relief valves’ that absorb heaving soils and eliminate significant structural cracking.
Second, and even though Wafflemat provides one of the stiffest cross sections per cubic yard of concrete, the system has less contact area with the underlying soils when compared with other slabs. And, less contact area means less uplift pressure on the slab when soils heave.
In terms of environmental impact, a Wafflemat foundation uses less concrete and steel, and reduces excavation of soils and accompanying off-haul when compared to other systems. This results not only in lower carbon emissions, but also less erosion and transport of sedimentation in drainage and storm runoff waters ultimately flowing into the ocean. Wafflemat also assists builders in obtaining LEED points, most likely in the categories Energy & Atmosphere, Materials and Resources, and Innovation and Design Process.
Finally, and even though Wafflemat’s track record of reliability is unparalleled, it’s consistently one of the most economical systems in all construction, as reductions in soils prep, materials, and cycletime often produce cost savings of 10% – 20% when compared to other foundations.
Turnkey concrete package for Los Angeles Hall of Justice
L.A. Hall of Justice
The Los Angeles Hall of Justice has been closed since the magnitude 6.7 1994 Northridge earthquake. The 335,000 sq. ft. building stands 14 floors tall in L.A.’s downtown. Originally constructed in 1925, this imposing structure was meant to convey a sense of justice and public importance. The Hall was designed in the classic Italianate style and was constructed with Type I non-combustible building materials including concrete floor slabs, a steel frame structure encased in concrete, granite exterior veneer, and hollow clay tile partitions at the interior. The Hall of Justice also presented a stunning interior with an ornate, barrel-vaulted entry foyer, gold-marble walls, and large ionic columns supporting the exquisitely gilded ceiling.
Although the building was completely abandoned following the earthquake, plans to revive it have been under consideration more than a decade. To date, all hazardous materials have been abated and all interior demolition of infrastructure systems and non-bearing walls have been completed. The building has been prepared for its eventual restoration and re-occupancy as an office building. After many years of designs and budgets, Clark Construction was awarded the job in a design build competition valued at $151,000,000.00.
A key part of the reconstruction is to preserve and restore the historic features of this important structure while bringing the building up to existing seismic codes. In order to accomplish this, shotcrete will be used extensively to reinforce existing concrete walls.
Conco’s scope of work will included all shotcrete, concrete, and rebar. We are also resurfacing the entire existing floor surfaces in the Hall of Justice structure and constructing a new 9 story, 1000 car parking structure on the same site.
Landscape contractor, Valley Crest Landscaping, was confronted with the task of filling newly constructed planter boxes around a new apartment complex in Pleasant Hill, CA. The site consisted of numerous buildings with tight access. The original plan was to use laborers with wheelbarrows to fill all of the planter boxes. It was estimated that the task would take more than a week to complete.
After consulting with Gary Brandt with Conco Pumping, Gary recommended that Valley Crest utilize Conco’s portable belts. These belts are capable of being deployed in tight spaces between buildings, can be configured to transport material around corners, use 110V single phase power, and can deliver material at the rate of 40 TPH.
With Conco’s portable belts, Valley Crest was able to complete the task in half the budgeted time using half the projected labor expense. Most important it allowed the GC the extra days needed to complete this project so the new tenants would be moved in on the dates promised by the owner.
Conco’s portable belts have many other practical uses. Some of the more notable uses include:
Import/export of material in confined space building basements
Back fill of retaining walls, abandoned swimming pools, etc.
Conveyance of masonry block, pavers and other building materials to upper level decks or into tight areas
Transportation of ballot boxes from delivery vehicles to counter rooms.
