Fracture properties of cement and alkali activated fly ash based concrete with application to segmental tunnel lining

Cement and alkali activated fly ash based concrete is analyzed.Fracture properties of various compositions are investigated both experimentally and numerically.Primary attention is accorded to the influence of the amount of fly ash replacing cement on fracture energy.The influence of short synthetic fibers on mechanical properties is also studied.Artificial neural network is introduced to provide parameters of the constitutive model. Several cement and alkali activated fly ash based concrete samples are examined in this paper with emphasis on their fracture properties. These are first obtained from an extensive experimental program. The measured loading curves are then compared with those derived numerically in the framework of an inverse approach. Here, the artificial neural network and the ATENA finite element code are combined to constitute the optimization driver that allows for a reliable determination of the modulus of elasticity, fracture energy, and tensile strength of individual concretes. A brief introduction to the numerical analysis of fiber reinforced specimens again in conjunction with inverse analysis is also provided.

[1]  R. Helmuth,et al.  Fly Ash in Cement and Concrete , 1987 .

[2]  Richard J. Beckman,et al.  A Comparison of Three Methods for Selecting Values of Input Variables in the Analysis of Output From a Computer Code , 2000, Technometrics.

[3]  Fernando Pacheco-Torgal,et al.  An overview on the potential of geopolymers for concrete infrastructure rehabilitation , 2012 .

[4]  Vít Smilauer,et al.  Material and structural characterization of alkali activated low-calcium brown coal fly ash. , 2009, Journal of hazardous materials.

[5]  Niels Olhoff,et al.  Sensitivity analysis of structures , 1997 .

[6]  Michal Šejnoha,et al.  Mixed Experimental and Numerical Approach to Evaluation of Material Parameters of Clayey Soils , 2004 .

[7]  D. C. Drucker,et al.  Thoughts on the present and future interrelation of theoretical and experimental mechanics , 1968 .

[8]  Venkatesh Kodur,et al.  Effect of Strength and Fiber Reinforcement on Fire Resistance of High-Strength Concrete Columns , 2003 .

[9]  Fernando Pacheco-Torgal,et al.  Are geopolymers more suitable than Portland cement to produce high volume recycled aggregates HPC , 2012 .

[10]  Pieter A. Vermeer,et al.  On the performance of a non-local softening model , 2004 .

[11]  Anna Kucerová,et al.  Back analysis of microplane model parameters using soft computing methods , 2009, ArXiv.

[12]  Jir ˇ íN emecek.  Nanoindentation characteristics of alkali-activated aluminosilicate materials , 2011 .

[13]  Ravindra Gettu,et al.  Fracture mechanics of concrete. A review , 1991 .

[14]  J. Pamin,et al.  Gradient-dependent plasticity in numerical simulation of localization phenomena , 1994 .

[15]  Vít Šmilauer,et al.  Nanoindentation characteristics of alkali-activated aluminosilicate materials , 2011 .

[16]  Jan Zeman,et al.  Applying genetic algorithms to selected topics commonly encountered in engineering practice , 2000 .

[17]  Vijander Singh,et al.  ANN-based estimator for distillation using Levenberg-Marquardt approach , 2007, Eng. Appl. Artif. Intell..

[18]  Petr Hlaváček,et al.  Micromechanical multiscale model for alkali activation of fly ash and metakaolin , 2011, Journal of Materials Science.

[19]  Surendra P. Shah,et al.  Fracture mechanics of concrete , 1995 .

[20]  J. Bijen,et al.  The reaction of fly ash in concrete a critical examination , 1989 .

[21]  Milan Jirásek,et al.  Comparison of integral-type nonlocal plasticity models for strain-softening materials , 2003 .

[22]  David Lehký,et al.  PARAMETERS OF CEMENT AND ALKALI ACTIVATED FLY ASH BASED CONCRETE : LABORATORY MEASUREMENTS AND NUMERICAL SIMULATION , 2014 .

[23]  David Lehký,et al.  ANN inverse analysis based on stochastic small-sample training set simulation , 2006, Eng. Appl. Artif. Intell..

[24]  David Lehký,et al.  Determination of statistical material parameters of concrete using fracture test and inverse analysis based on FraMePID-3 PB tool , 2012 .