Relationships among Elastic Wave Velocities and Stress-Strain Responses in Mortar or Concrete Specimens under Uniaxial Compressive Load: Elastic wave propagation properties of rock materials (mortar or concrete) under load (I) - KOYAMA, Shuhei; NAKAYA, Mitsuo; OKUNO, Hizuru (Transactions of The Japanese Society of Irrigation, Drainage and Reclamation Engineering, 1980)