Deconstructable Steel-Concrete Shear Connection for Sustainable ...
Graduate Category: Engineering and Technology Degree Level: Ph.D Abstract ID# 882
Deconstructable Steel-Concrete Shear Connection for Sustainable Composite Floor Systems Lizhong Wang1, Clayton Brown2, Mark D. Webster3, and Jerome F. Hajjar4 1Graduate
Research Assistant, Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, [email protected] 2Staff I – Structures, Simpson Gumpertz & Heger Inc., Waltham, MA , [email protected] 3Senior Staff II – Structures, Simpson Gumpertz & Heger Inc., Waltham, MA , [email protected] 4CDM Smith Professor and Chair, Department of Civil and Environmental Engineering, Northeastern University, Boston, MA [email protected]
Introduction According to the U. S. Department of Energy, the construction and use of commercial and residential buildings accounted for nearly half of the U.S. energy consumption in 2011. A new design approach, known as Design for Deconstruction (DfD), has emerged to facilitate future reuse of materials.
Reaction Angle
Self-reacting Frame Precast Concrete Plank
Steel Beam
a) Pushout Test
Spreader Beams Precast Concrete Planks Lateral Bracing Precast Concrete Planks
Figure 1. U.S. Energy Consumption by Sector
Figure 2. End-of-life of Construction Materials
Image from US Energy Information Administration (2011)
Image from SteelConstruction.Info
Contrary to the conventional linear material flow, which starts with the extraction of raw materials and ends with the disposal of debris in landfills, DfD helps close this loop by reducing the cost of recovering and reusing resources. Design for Deconstruction
Extraction
Manufacturing
Construction
Operation
Deconstruction
Chord
Steel Collector Steel Brace
Timber Supports
Steel Beam
c) Composite Diaphragm Test
b) Composite Beam Test
Figure 8. Experimental Program
Life Cycle Assessment Life Cycle Assessment (LCA) employs life-cycle inventories (LCI) to quantify the environmental impacts of a product or system. An LCI is an accounting of environmentally significant inputs, such as embodied energy and materials, and outputs, such as pollutants, in the product or system throughout its life cycle.
Disposal
Figure 3. Material Flow in Buildings
Deconstructable Composite Floor System Components • Concrete floor planks: prefabricated for maximum efficiency • Cast-in channels: embedded in the concrete planks to provide flexibility for where the beam intersects the plank and to allow for different beam widths • Bolts and clamps: firmly clamp the steel beam and the concrete plank together and utilize frictional forces to achieve composite action in the flooring system • Tongue and groove mating edges: ensure the adjacent planks share load and offer a level and well-matched surface Precast concrete plank Cast-in channels
Steel beam Tongue and groove side joint
Bolts
A parametric study is conducted to compare the environmental impacts of prototype structures with different parameters. The effect of the percentage of reusable DfD components is studied only for 30-9-6 and 30-9-8. Three different percentages are assumed: 66%, 75%, and 80%. Table 1. Prototype Structure Matrix Frame Number
Name
Bay width (ft.)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
20-3-6-ss 20-3-8-ss 20-9-6-ss 20-9-8-ss 30-3-6-ss 30-3-8-ss 30-9-6-ss 30-9-8-ss 20-3-6-gc 20-3-8-gc 20-9-6-gc 20-9-8-gc 30-3-6-gc 30-3-8-gc 30-9-6-gc 30-9-8-gc
20 20 20 20 30 30 30 30 20 20 20 20 30 30 30 30
Number of stories 3 3 9 9 3 3 9 9 3 3 9 9 3 3 9 9
Concrete plank thickness(in.) 6 8 6 8 6 8 6 8 6 8 6 8 6 8 6 8
Connections between concrete and steel Headed stud anchors Headed stud anchors Headed stud anchors Headed stud anchors Headed stud anchors Headed stud anchors Headed stud anchors Headed stud anchors Girder clamps Girder clamps Girder clamps Girder clamps Girder clamps Girder clamps Girder clamps Girder clamps
0.80
Clamps
30'
10'
Figure 6. Precast Concrete Plank Cross Section (units: inches)
0.10
Figure 7. Typical Floor Plan for DfD System (units: feet) 0.00
• Composite beam tests: evaluate the clamping connection within a full-scale composite beam test • Composite diaphragm tests: study the in-plane seismic behavior of the diaphragm floor system, including the chords, the collectors and the connections between the collectors and the lateral-force-resisting system
Fossil Fuel Depletion (MJ surplus)
Global Warming (kg CO2 eq)
Respiratory Effects (kg PM2.5 eq)
Smog (kg O3 eq)
Ecotoxicity (CTUe)
Test Program • Pushout tests: quantify the strength and ductility of the clamping connectors, evaluate a wide range of parameters, and formulate strength design equations
0.48 0.53 0.46 0.50 0.47 0.52 0.56 0.47 0.42 0.60 0.51 0.45
b) Plank parallel to the steel girder
0.20
0.39 0.40 0.37 0.38 0.38 0.39 0.43 0.37 0.34 0.44 0.38 0.35
12''
0.31 0.36 0.30 0.35 0.31 0.36 0.40 0.31 0.26 0.45 0.35 0.29
12''
0.30
0.49 0.56 0.45 0.51 0.48 0.55 0.57 0.47 0.42 0.64 0.53 0.46
30'
12''
30'
12''
10'
12''
0.40
10'
6 ''
10'
10'
a) Plank perpendicular to the steel beam
0.50
0.05 0.06 0.04 0.05 0.05 0.05 0.05 0.04 0.03 0.05 0.04 0.04
30'
10' 10' 10'
6'' 6''
12''
0.60
Relative Environmental Impacts
30'
10'
30'
24''
6''
0.70
Figure 5. Deconstructable Composite Beam Prototype
Figure 4. Conventional Composite Structures Image from McGraw-Hill Concise Encyclopedia of Engineering. © 2002 by The McGraw-Hill Companies, Inc.
20-3-6
20-3-8
20-9-6
20-9-8
30-3-6
30-3-8
30-9-6 0.66
30-9-6 0.75
30-9-6 0.80
30-9-8 0.66
30-9-8 0.75
30-9-8 0.80
Figure 9. Environmental Impact Comparison after Three Cycles References Energy Information Administration (EIA) (2010). Assumptions to the Annual Energy Outlook 2010,U.S Energy Information Administration, Washington, D.C., April. Halfen (2011). Halfen Anchoring Systems, Halfen, Converse, Texas. Lindapter (2011). Steelwork Fixings Catalogue, Lindapter, Bradford, U.K. Wang, L., Webster, M. D., Hajjar, J. F. (2015). “Behavior of Deconstructable Steel-Concrete Shear Connection in Composite Beams,” Proceedings of the ASCE/SEI Structures Congress 2015, Portland, Oregon, April 23-25, 2015. Wang, L., Webster, M. D., Hajjar, J. F. (2015). “Diaphragm Behavior of Deconstructable Composite Floor Systems,” 8th International Conference on Behavior of Steel Structures in Seismic Areas, Shanghai, China, July 1-3, 2015
Deconstructable Steel-Concrete Shear Connection for Sustainable Composite Floor Systems Lizhong Wang1, Clayton Brown2, Mark D. Webster3, and Jerome F. Hajjar4 1Graduate
Research Assistant, Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, [email protected] 2Staff I – Structures, Simpson Gumpertz & Heger Inc., Waltham, MA , [email protected] 3Senior Staff II – Structures, Simpson Gumpertz & Heger Inc., Waltham, MA , [email protected] 4CDM Smith Professor and Chair, Department of Civil and Environmental Engineering, Northeastern University, Boston, MA [email protected]
Introduction According to the U. S. Department of Energy, the construction and use of commercial and residential buildings accounted for nearly half of the U.S. energy consumption in 2011. A new design approach, known as Design for Deconstruction (DfD), has emerged to facilitate future reuse of materials.
Reaction Angle
Self-reacting Frame Precast Concrete Plank
Steel Beam
a) Pushout Test
Spreader Beams Precast Concrete Planks Lateral Bracing Precast Concrete Planks
Figure 1. U.S. Energy Consumption by Sector
Figure 2. End-of-life of Construction Materials
Image from US Energy Information Administration (2011)
Image from SteelConstruction.Info
Contrary to the conventional linear material flow, which starts with the extraction of raw materials and ends with the disposal of debris in landfills, DfD helps close this loop by reducing the cost of recovering and reusing resources. Design for Deconstruction
Extraction
Manufacturing
Construction
Operation
Deconstruction
Chord
Steel Collector Steel Brace
Timber Supports
Steel Beam
c) Composite Diaphragm Test
b) Composite Beam Test
Figure 8. Experimental Program
Life Cycle Assessment Life Cycle Assessment (LCA) employs life-cycle inventories (LCI) to quantify the environmental impacts of a product or system. An LCI is an accounting of environmentally significant inputs, such as embodied energy and materials, and outputs, such as pollutants, in the product or system throughout its life cycle.
Disposal
Figure 3. Material Flow in Buildings
Deconstructable Composite Floor System Components • Concrete floor planks: prefabricated for maximum efficiency • Cast-in channels: embedded in the concrete planks to provide flexibility for where the beam intersects the plank and to allow for different beam widths • Bolts and clamps: firmly clamp the steel beam and the concrete plank together and utilize frictional forces to achieve composite action in the flooring system • Tongue and groove mating edges: ensure the adjacent planks share load and offer a level and well-matched surface Precast concrete plank Cast-in channels
Steel beam Tongue and groove side joint
Bolts
A parametric study is conducted to compare the environmental impacts of prototype structures with different parameters. The effect of the percentage of reusable DfD components is studied only for 30-9-6 and 30-9-8. Three different percentages are assumed: 66%, 75%, and 80%. Table 1. Prototype Structure Matrix Frame Number
Name
Bay width (ft.)
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
20-3-6-ss 20-3-8-ss 20-9-6-ss 20-9-8-ss 30-3-6-ss 30-3-8-ss 30-9-6-ss 30-9-8-ss 20-3-6-gc 20-3-8-gc 20-9-6-gc 20-9-8-gc 30-3-6-gc 30-3-8-gc 30-9-6-gc 30-9-8-gc
20 20 20 20 30 30 30 30 20 20 20 20 30 30 30 30
Number of stories 3 3 9 9 3 3 9 9 3 3 9 9 3 3 9 9
Concrete plank thickness(in.) 6 8 6 8 6 8 6 8 6 8 6 8 6 8 6 8
Connections between concrete and steel Headed stud anchors Headed stud anchors Headed stud anchors Headed stud anchors Headed stud anchors Headed stud anchors Headed stud anchors Headed stud anchors Girder clamps Girder clamps Girder clamps Girder clamps Girder clamps Girder clamps Girder clamps Girder clamps
0.80
Clamps
30'
10'
Figure 6. Precast Concrete Plank Cross Section (units: inches)
0.10
Figure 7. Typical Floor Plan for DfD System (units: feet) 0.00
• Composite beam tests: evaluate the clamping connection within a full-scale composite beam test • Composite diaphragm tests: study the in-plane seismic behavior of the diaphragm floor system, including the chords, the collectors and the connections between the collectors and the lateral-force-resisting system
Fossil Fuel Depletion (MJ surplus)
Global Warming (kg CO2 eq)
Respiratory Effects (kg PM2.5 eq)
Smog (kg O3 eq)
Ecotoxicity (CTUe)
Test Program • Pushout tests: quantify the strength and ductility of the clamping connectors, evaluate a wide range of parameters, and formulate strength design equations
0.48 0.53 0.46 0.50 0.47 0.52 0.56 0.47 0.42 0.60 0.51 0.45
b) Plank parallel to the steel girder
0.20
0.39 0.40 0.37 0.38 0.38 0.39 0.43 0.37 0.34 0.44 0.38 0.35
12''
0.31 0.36 0.30 0.35 0.31 0.36 0.40 0.31 0.26 0.45 0.35 0.29
12''
0.30
0.49 0.56 0.45 0.51 0.48 0.55 0.57 0.47 0.42 0.64 0.53 0.46
30'
12''
30'
12''
10'
12''
0.40
10'
6 ''
10'
10'
a) Plank perpendicular to the steel beam
0.50
0.05 0.06 0.04 0.05 0.05 0.05 0.05 0.04 0.03 0.05 0.04 0.04
30'
10' 10' 10'
6'' 6''
12''
0.60
Relative Environmental Impacts
30'
10'
30'
24''
6''
0.70
Figure 5. Deconstructable Composite Beam Prototype
Figure 4. Conventional Composite Structures Image from McGraw-Hill Concise Encyclopedia of Engineering. © 2002 by The McGraw-Hill Companies, Inc.
20-3-6
20-3-8
20-9-6
20-9-8
30-3-6
30-3-8
30-9-6 0.66
30-9-6 0.75
30-9-6 0.80
30-9-8 0.66
30-9-8 0.75
30-9-8 0.80
Figure 9. Environmental Impact Comparison after Three Cycles References Energy Information Administration (EIA) (2010). Assumptions to the Annual Energy Outlook 2010,U.S Energy Information Administration, Washington, D.C., April. Halfen (2011). Halfen Anchoring Systems, Halfen, Converse, Texas. Lindapter (2011). Steelwork Fixings Catalogue, Lindapter, Bradford, U.K. Wang, L., Webster, M. D., Hajjar, J. F. (2015). “Behavior of Deconstructable Steel-Concrete Shear Connection in Composite Beams,” Proceedings of the ASCE/SEI Structures Congress 2015, Portland, Oregon, April 23-25, 2015. Wang, L., Webster, M. D., Hajjar, J. F. (2015). “Diaphragm Behavior of Deconstructable Composite Floor Systems,” 8th International Conference on Behavior of Steel Structures in Seismic Areas, Shanghai, China, July 1-3, 2015
