Abstract:
Demolition of concrete and rock is a common pI:.ocess in many
construction, renovation and rehabilitation projects. Non-explosive Demolishing
Material (NEDM) has been a popular alternative for explosive or mechanical
demolishing activities due to the lack of noise and vibration. NEDM is a dry,
powdery material that expands considerably when mixed with water. When two
consecutive drill holes in rock or concrete are loaded with NEDM, the pressure
developed by NEDM gives rise to stress concentrations among the holes causing
the rock to fracture. However, NEDM is not yet economically competitive, with
explosives and any means of optimizing on their use is considered desirable.
This study examines the factors affecting the performance of NEDM in the
laboratory environment using unreinforced concrete blocks by ana lysing crack
initiation and crack expansion. It was found that the performance of the NEDM
is a function of water content, water temperature, field temperature and the
brand used. Further Research was conducted to examine the possibility of
adding an inert material to the NEDM in order to reduce the cost. Research was
also conducted to improve the workability of the NEDM by the addition of
super plasticizer to the slurry. .
