In this study, a reference function was derived for the relationship between scaled distance and typical blast wave parameters, including time of arrival (^t _A ), peak overpressure (p ⁺), positive duration (t ⁺), and positive impulse (i ⁺). A blast wave was generated using a right cylindrical cast TNT charge of weight 10.1-160 kg and a scaled height of burst of approximately 0.18 m･kg ^－1/3 in field experiments. Each pressure profile was measured using piezoelectric pressure sensors installed at a height of 1 m over a mass-scaled distance (Z) of 1.88 to 148.9 m･kg ^－1/3. The relationship between Z and each mass scaled blast parameters (T _A, P ⁺, T ⁺, I ⁺) was approximated using cubic natural spline functions. Compared to the surface explosion of hemispherical TNT, the shape of the explosive had a significant effect below 4 m･kg ^－1/3, resulting in larger P ⁺ and smaller T ⁺.

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The effect of rebar in reinforced concrete on blasting demolition was clarified through laboratory tests. In this study, blasting tests were conducted using concrete plate specimens containing iron bar, and the strain/stress state around the rebar and crack propagation were examined. The strain generated in the specimen after ignition of the explosive was calculated by the digital image correlation method. This method successfully visualized cracks that could not be seen visually and clarified stress wave propagation and crack propagation behavior around the rebar before and after crack initiation. The results showed that the presence of rebar in the propagation path of a stress wave causes more regular cracking than when no rebar is present due to reflection and diffraction of the stress wave.

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