Hybrid Concrete construction : maximising the potential
of concrete by combining precast and in-situ concrete
Presented by:
Vincent TEISSIER, Christophe BERGER
LafargeHolcim Center of Research
WARNING BEFORE WE GET STARTED….
CONTENTS
• Introduction
• Typical hybrid options & case studies
• In-house examples
•
•
Pre-walls
Concrete-wood solutions
• Conclusions
CONTENTS
• Introduction
• Typical hybrid options & case studies
• In-house examples
•
•
Pre-walls
Concrete-wood solutions
• Conclusions
Introduction
The search for greater economy, in terms of material costs and reduced
construction time, has resulted in innovative approaches that seek to combine
construction materials and methods to optimum effect.
Hybrid construction combines the most appropriate materials and methods of
construction to produce simple, buildable and economic structures which result in
faster, safer construction and reduced costs.
Hybrid Concrete construction combines the benefits of precasting with all the
benefits of in-situ concreting
Precast Concrete
In-situ concrete
Precast Concrete
Economic for repetitive elements
Long clear spans
Speed of erection
Buildability
High quality finishes
Accuracy
Reduced propping on site
Reduced skilled labor on site
Economic for bespoke areas
Continuity
Robustness
Design flexibility
Locally sourced materials
Short lead-in times
Durability
Economic for repetitive elements
Long clear spans
Speed of erection
Buildability
High quality finishes
Accuracy
Reduced propping on site
Reduced skilled labor on site
CONTENTS
• Introduction
• Typical hybrid options & case studies
• In-house examples
•
•
Pre-walls
Concrete-wood solutions
• Conclusions
Typical hybrid options *
Jubilee Library, Brighton.
* From « Hybrid concrete construction » guide
Some case studies *
Jubilee Library, Brighton.
« Ideas Store », UK.
« West Quay car park », UK.
Gatwick airport
Toyota HQ
* from « Hybrid concrete construction » guide & « Best practice guidance for Hybrid concrete construction »
CONTENTS
• Introduction
• Typical hybrid options & case studies
• In-house examples
•
•
Pre-walls
Concrete-wood solutions
• Conclusions
Pre-Wall System
Precast twin wall system linked by steel connectors and filled by in-situ
concrete
No formwork, good quality finish due to precast manufacturing, structural
load bearing capacity
Pre-Wall System – main applications
Residential buildings, offices, car parks, schools, military, etc.
Industrial buildings : fire walls, technicals, etc.
Miscellaneous : fences, basins, silos, waste recycling plants, sound insulation
walls, etc.
Pre-Wall System – technical description
2 pre-cast walls with independent dimensions
(40-50MPa)
Wall thicknesses from 4.5cm to 7cm
Average weight 250 kg à 350 kg/m²
Minimum steel reinforcement 6.5 kg/m²
All steel parts integrated
Pre-Wall System – a technically-challenging manufacturing
process
Pre-Wall System – job site management
On job sites, pre-wall elements can be turned upside-down automatically (1)
Full truck loads can be stored on job sites (2)
Cranes are required to manipulate heavy elements (3)
(3)
(3)
(2)
(1)
Pre-Wall System – filling up of pre-walls by in-situ concrete
The filling operation of the pre-wall cavity with in-situ concrete should be
done with care, in order to not blow-up the 2 wall elements due to
hydrostatic pressure
In particular, it is recommended to not exceed 70cm filling height , then
allow about 1h between 2 filling operations
Typical issues observed can be air pockets, segregation, etc. A
recommended solution would be to use Self Compacting Concrete rather
than regular concrete
CONTENTS
• Introduction
• Typical hybrid options & case studies
• In-house examples
•
•
Pre-walls
Concrete-wood solutions
• Conclusions
Concrete-Wood solution : a composite system associating
precast & in-situ concrete + wood frames
Architectural view of « Jardins de Jules » - LYON
Concrete-Wood solution – description of the system (1/2)
•
Precast panel composed of a concrete wall + a wood frame provided to host
insulation materials, linked together with elements of galvanised steel
•
Development driven by the thermal constraints linked with RT2012 (insulation
thickness & air tightness)
Galvanised
steel connector
Wood frame
Concrete
external skin
Max dimensions : 3m x 5,2m
Possible thickness : 280, 300, 320, 340 mm
Weight/m² : 192 to 196 kg/m²
Concrete-Wood solution – description of the system (2/2)
Structural concept :
• Column / beam for the
facade
• Load bearing wall for the
interior wall
• Cast in place solid slab
Cast in place
slab
Cast in place
column
Concrete-Wood solution – addition of insulation material
Exterior
Rockwool insulation (95+120mm)
Rockwool insulation (50mm)
Interior
THERMAL FLOW
Concrete-Wood solution – typical job site practices (1/6)
Transportation of panels on
horizontal position
Lifting with tower crane
Concrete-Wood solution – job site practices (2/6)
Elements are re-positioned vertically for handling by specific hydraulic tools
Concrete-Wood solution – job site practices (3/6)
Preparation of panel support on
the slab
Bed of sealant
Concrete-Wood solution – job site practices (4/6)
Push-pull props also used for
adjustment of wall alignment
Concrete-Wood solution – job site practices (5/6)
Waterproofing
membrane
Rockwool insulation
Steel reinforcement
Concrete-Wood solution – job site practices (6/6)
Plywood formwork
Cast in place
column supporting
slab
Concrete-Wood solution – job site overview (1/3)
Concrete-Wood solution – job site overview (2/3)
Concrete-Wood solution – job site overview (3/3)
Concrete-Wood solution – key points to remember
•
Increased speed of construction by maximising contribution from
precast
•
Improved safety on site, no use of scaffolding
•
“Clean” job sites, with limited use of formwork
•
Various type of finish for external skins (colour, matrix, aesthetic
concrete)
•
High thermal insulation and air tightness
CONTENTS
• Introduction
• Typical hybrid options & case studies
• In-house examples
•
•
Pre-walls
Concrete-wood solutions
• Conclusions
Conclusions
•
Hybrid Concrete construction combines the benefits of precasting with all the
benefits of in-situ concreting
•
To date, cost savings up to 30%* have been achieved by using hybrid construction
•
Looking ahead, greater potential is likely going to be achieved by combining all of
these elements with fully integrated design opportunities offered by the BIM
(Building Information Model) technology
• Best practice guidance for hybrid construction, Goodchild & Glass
use of a hybrid concrete frame instead of a composite steel frame on a
shell-and-core office project in central London led to savings of 29% and increased net
lettable floor area from 33,700 m2 to 38,200 m2 – (a 13% increase)11.
Concept
Plot of land
Numerical model
Structure design
Services
Thank you
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