construction materials and at plup olyu

Construction Materials and Structural Engineering Research 

t P l Uat PolyU

Department of Civil and Structural Engineering

Eco‐friendly yConstruction Materials 

Professor Chi‐Sun PoonProfessor Chi Sun Poonwww.eco‐block.hk

Department of Civil and Structural Engineering

Construction and Demolition Waste• 20 Million tonnes

Batching plants

ExcavationRoad Work

ConstructionDemolitionC&D Waste

Refurbishment

Department of Civil and Structural EngineeringRenovation

Construction and Demolition Waste

C & DWasteC & D Waste

Inert i

Non inert iConstruction 

WasteConstruction 

Waste

Land  RecycledReclamation & Site Formation

Recycled Aggregates Landfill

Department of Civil and Structural Engineering

Waste GlassWaste Glass

Hong Kong : in 2009About 300  tonnes per day; 

about 1% recycled99% landfilled

Department of Civil and Structural Engineering

99% landfilled

R l d A t f C t Li it tiRecycled Aggregates for Concrete : Limitations

•High water absorption (in particular, the recycled fines)

•presence of contaminants and other foreign materials

•Compressive strength, tensile strength and bond strength of concrete would be reduced

•Drying shrinkage is higher and the creep of concrete may increase.

Department of Civil and Structural Engineering

Eco‐blocks 環保磚

Alt ti ti P t b i k d

環保磚

• Alternative casting : Pre‐cast bricks and blocks (dry mixed) 

• Use with waste glass to enhance aesthetics and water absorption propertiesand water absorption properties 

• Use with photo‐catalyst  for valued added properties

Department of Civil and Structural Engineering

Air Pollutant Removal Paving BlocksAir Pollutant Removal Paving BlocksEco-blocks - 3rd Generation

Sunlight Air Pollutants (NOx) Precipitation

Surface layerCement +Recycled Glass + Recycled Aggregate + Photo-catalyst

NO3TiO2

Base layer Cement + Recycled Aggregate + Recycled GlassRecycled Glass

Department of Civil and Structural Engineering

Eco‐Blocks 環保磚

第一代

第二代第二代

Recycled AggregateRecycled Aggregate + Recycled Glass

第三代

Recycled Glass + Recycled Aggregate + Photo-catalyst

Department of Civil and Structural Engineering

Examples of field applicationsExamples of field applications

Department of Civil and Structural Engineering

4th Generation Eco‐blocks Made with Waste glassGe e at o co b oc s ade t aste g ass

Self cleansing and disinfection functions

Web-site : www.eco-block.hk

Department of Civil and Structural Engineering

From raw materials to finished products

Ingredients:WC:MK:CG:FG

Fine glass (FS)            Coarse glass (CG)

(0.9:0.1:0.6:1.4)

Metakaolin (MK)       White cement (WC)

Constituents andrecycled glass weremixed in mixer

Department of Civil and Structural EngineeringHardened architecture concrete with desired shape

Performance of HSC under fire : Dr Y.L Wong

High strength concrete (HSC) with granite aggregates fully saturated with water, Heating rate = 2 /minute, spalled at about 450℃

Department of Civil and Structural Engineering

at about 450℃

Effects of Coating on HSC Columns Under Standard Fire (by PolyU and SCUT)(by PolyU and SCUT)

Column size:

400x400x2000

Upper column C8: fully saturated with water

Lower column C1: air‐cured

fcu = 86 MPa

Department of Civil and Structural EngineeringAxial load = 3000 kN

Effects of Coating on HSC Columns under Standard Fire (by PolyU and SCUT)(by PolyU and SCUT)

Department of Civil and Structural Engineering

C8, C1: Severe concrete spalling at 20 minutes

Effects of Coating on HSC Columns under Standard Fire (by PolyU and SCUT)(by PolyU and SCUT)

Upper column C5: Intumescent coating burnt off at 30 minutes, severe concrete spalling at 40 minutes

Department of Civil and Structural Engineering

pp g , p g

Lower column C2: Mosaic tiles detached at 30 minutes, severe concrete spalling at 40 minutes

Assessment of Fiber Distribution in Fiber Reinforced Concrete 

Dr Eddie S.S. Lam 

• To develop a procedure to access the• To develop a procedure to access the distribution of fibers

• To relate the distribution of fibers with workability, tensile strength, etc.workability, tensile strength, etc.

• To recommend appropriate quality d fib di ib iassurance procedures on fiber distribution 

and/or fiber concentration

Department of Civil and Structural Engineering

Fracture surfaces: mark the fibersFracture surfaces: mark the fibers

Department of Civil and Structural Engineering

Cut surface: expose the fibersCut surface: expose the fibers

Some of the fibers were pulled out from the splitting‐plane leading to loss of number ofleading to loss of number of fibers.Therefore, we carry out studies on cut surfaceon cut surface.Cut surface is immersed in (10%) hydrochloric acid to di l th t tdissolve the cement paste.After that, fibers can be shown clearly.Counting of fibers is still in progress.

Department of Civil and Structural Engineering

Research on Emerging Structural Materials and St t l S tStructural Systems

Prof. Jin-Guang TENG Dr. Jian-Guo DAI

Chair ProfessorDepartment of Civil and Structural Engineering

Assistant ProfessorDepartment of Civil and Structural EngineeringStructural Engineering

Tel: (852) 2766 6012Fax: (852) 2766 1354

Structural Engineering

Tel: (852) 2766 6026Fax: (852) 2334 6389

E-mail: cejgteng@polyu.edu.hk

Current research foci:

( )E-mail: cejgdai@polyu.edu.hk

• Fibre-reinforced polymer (FRP) composites for the strengthening of existing structures

• S i i t d t fit f RC t t• Seismic assessment and retrofit of RC structures

• Performance of FRP composites in severe environments

Department of Civil and Structural Engineering• Hybrid structures incorporating FRP composites

Strengthening of concrete structuresStrengthening of concrete structures

• World-leading research on FRP gstrengthening of concrete structures

• Research results adopted by• Research results adopted by American, UK and Australian guidelines and the Chinese National Standard

• One of the main groups for the drafting of the Chinese National Standard forNational Standard for Infrastructure Application of FRP Composites

• Currently working on Hong• Currently working on Hong Kong Guidelines for the Strengthening of Concrete

Department of Civil and Structural Engineering

Structures Using FRP Composites (ITF Funded)

Seismic assessment and retrofitSe s c assess e t a d et o t

Development of a computational platform for the seismic assessment and retrofit of RC buildings, based on OpenSees(Open System for Earthquake Engineering Simulation)

Department of Civil and Structural Engineering

(Open System for Earthquake Engineering Simulation)

FRP-strengthened concrete structures in severe environmentssevere environments

Location I

PolymeradhesiveCFRPInsulationmaterials

D bilit f FRP t th dFire performance of un-protected and insulated FRP-strengthened RC structures

Durability of FRP-strengthened concrete structures in a sub-tropical climate: accelerated and field exposure tests

Department of Civil and Structural Engineering

g exposure tests

Hybrid structures incorporating FRP compositesy p g p

Hybrid FRP-concrete-steel d bl ki b l l

Smart FRP bars as double-skin tubular structural members as columns and beams

reinforcement for concrete structures

Department of Civil and Structural Engineering

Other Research Areas

•Structural Steel•Structural Health Monitoring

•Structural Dynamic•Structural Dynamic

Department of Civil and Structural Engineering