Tada, Masaru creator Horii, Hideyuki Chairperson Pama, Ricardo P. Examination Committee Ueda, Tamon Examination Committee Th e Royal Thai Government Scholarship donor text th Bangkok Asian Institute of Technology 1990 monographic eng

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60, [79] p. An accurate in-plane displacement measurement system was established based on the laser speckle method in order to measure displacement field due to crack propagation on the surface of a wedge - load- type specimen of concrete or mortar. Crack growth behavior on the specimen surface was observed utilizing the established measurement system. Fracture process zone in the specimen was modelled with the Dugdale-Barenblatt- type model employing tension - softening relation as material property under tensile fracture. Analysis based on the boundary element method was then performed on this analytical model . The results obtained by the observation and the analysis were compared. The predicted maximum load value was in a relatively good accord with the obtained maximum load value in the fracture test for crack observation . The predicted distribution of crack opening displacement (crack profile) agreed with the observed crack profile when load was relatively small. However, with increasing load the observed crack length became larger and crack opening was detected ahead of the predicted crack tip . Accordingly shape of the observed crack profile differs from the prediction by the present model. Possible causes which account for this discrepancy were discussed. Measurement of tension-softening relation was attempted based on the J-integral method on both concrete and mortar . The obtained tension-softening curve was far from reported results obtained using the same method as well as a Problems in the method were pointed out and discussed. in previous researches direct tension test. possible causes were A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Engineering and Technology Thesis (M.Eng.) - Asian Institute of Technology, 1990 Concrete Cracking Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B18571 http://203.159.5.9/ait-thesis/detail.php?q=B18571 270798 20260818170351.0