Practical Application of Static Rock Breaker Using TiNi Shape Memory Alloy

A newly invented static rock breaker using TiNi shape memory alloy has been proposed. The breaker consisted of compressively pre-strained TiNi rods of 15mm in diameter and 29mm in height and a pair of two-layered wedge type platens of steel, and required no accessory equipments other than heating apparatus. The maximum breaking force per unit length of the breaker was 3 to 5MN/m. The total breaking force was about 300 to 900kN, depending on the number of TiNi rods used. To examine the practicality, the breaker has been applied to concrete wall of building, natural boulder, etc. It was confirmed that the breaker was not lack in terms of performance and was possible to control the direction of crack initiation and propagation. It can be concluded that TiNi shape memory alloy has a bright prospect as a solid pressure source.