Session 4 Reference Values for Durability Design Dr. Paul J. Tikalsky, P.E., FACI The Pennsylvania State University USA

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Defining Durability Detailed Knowledge Structural Requirements Environment Material Science Deterioration Mechanisms

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Structural Requirements Define the precise design function Compression, Tension, Shear, Combined? Stiffness? Brace? Load Sharing? Define the structural design RV Define the long term and short term behavioral requirements of the structure Define the desired design life

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Define the Environment Concentrations of chemical and gases Wet/Dry cycles Freeze/Thaw cycles Physical loadings Abrasion Fluid contact and velocity Vibrations/Repeated cycles

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Level of Chemical Exposure Chemical Exposure Sulfate concentration (0-5% SO 4 -2 ) Chloride concentration (0-3 kg/m 3 ) Carbon dioxide or monoxide concentration Acid concentration and type Other chemical concentrations

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Creating Reference Values Reference Values for Durability depend on multiple variables Desired years of service Acceptability or Consequences of deterioration (nuclear power plant or retail space) Compounding exposure conditions Time of testing or evaluation

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Material Science Models Appropriate models must exist for the prediction of deterioration Time based models that progress with predictably changing exposure conditions

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Chloride Diffusion Model C (x,t) = chloride concentration t = time x = depth C o = surface chloride concentration D c = chloride diffusion constant erf = Error Function

Chloride Concentration and Diffusion Constant

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Chloride Concentration vs Time

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Subsidence Cracking Model p = probability of settlement cracking y = x x x 3 x 1 = concrete cover, mm x 2 = concrete cover / bar size x 3 = concrete slump, mm

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Permeability K C = permeability coefficient Q = rate of flow H/L = ratio of head of fluid to percolation length A = cross section area under pressure

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Chloride Penetration Test Method: AASHTO T277 (Coulombs passed in 6 hours)

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic

Ex: Defining Permeability Performance

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Ex: Defining Shrinkage Performance

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Ex: Defining ASR Performance

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Ex: Defining Sulfate Performance

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Models and Design Decisions Do models exist to predict durability based performance? Are the models based on materials science? How can tests at the time of construction be verified by field performance?

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Combined Effects Many durability problems are a result of multiple distress mechanisms. How can a more holistic model be developed and implemented? (e.g. “Life 365”)

Euro-SiBRAM’2002 Prague, June 24 to 26, 2002, Czech Republic Prof. Paul J. Tikalsky, P.E., FACI Penn State University Transportation Infrastructure Lab Research Drive State College, PA USA

Chloride Concentration and Cover Depth