A thesis submitted in partial fulfilment of the requirement for the degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1989

A method of computing deflections based upon effective moment of inertia is proposed. It compares well with Branson 's, CEB and A.W.Beeby methods. The tension stiffening coefficient is adopted from CEB method with a different power of m in ( ::')"' . Another method of computing de flections is developed \ {u2022} I based upon direct sectional analysis with consideration of concrete tension stiffening. When the total concrete area in tension is considered effective, the method gives a good agreement with Branson's way at working moments. However, it does not come up with good comparison with Branson's method when moment approaches yield moment. The study with effective area i.e; region a round bar and one strained below Eiu , contributing for tension shows a possibility for complete agreement. However, it needs a careful and extensive study with various types of stress-strain relationships for concrete in tension. Laser speckle technique is applied to measure inelastic rotation at crack. The method is found to be quite effective and satisfactory for flexure test. The measured inelastic deflection indicated t he applicability of the assumption that "the in elastic rotation is lumped at crack".