The optimization of field parameters of non-explosive demolishing agent

Abstract

Demolition of concrete and rock is a common process 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 analysing 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.