Expansive mortar for rock fracturing in underground excavation
Date of Issue2018
School of Civil and Environmental Engineering
This purpose of this project is to act as a pilot study on the performance of expansive mortar also known as Soundless Chemical Demolition Agents (SCDA). Information regarding the performance of SCDA outside conditions specified by the manufacturers are limited and thus the impetus for this project was to collect data on the performance of the SCDA outside of what has been provided by its manufacturers. The experiment in this project was designed to the measure how the performance of the SCDA would be affected by the change in the ambient temperature, it’s water content and the borehole diameter. For this purpose, concrete blocks were prepared and the SCDA was used to induce brittle failure in the blocks. This was done by drilling a hole in the middle of the block and filling it with a slurry of SCDA and water. Strain gauges were attached to the blocks identify the exact time of failiure of the concrete blocks. The data gathered from the experiments suggest all three variables, have a significant impact on the performance of the SCDA. It was observed that a higher ambient temperature, larger borehole diameter and lower water content diameter resulted in the better performance of the SCDA. It was also observed that the conditions in which the SCDA resulted in faster cracking of the samples had a different crack pattern compared to the samples which took longer to crack.
Final Year Project (FYP)
Nanyang Technological University