Poschner Construction Ltd.
Removing rock using GeoBreak Expanding Grout on congested job site –Vancouver, BC – completed February 2019
Scope of the Project
- Use GeoBreak Expanding Grout to heave apart rock to allow for a ripper to pull away material once it is cracked and broken.
- Non-explosive, cost effective alternative required to break the rock in downtown Vancouver.
A hard sandstone was exposed that required removal for a crane pad footing excavation off Dunlevy Ave in Vancouver. The rock that was originally dug up had approximate dimensions of 20’ x 20’ x 3’. Further excavation revealed more rock that required breaking. This project was in close proximity to surrounding buildings/structures, and equipment which made traditional blasting prohibitied. Using a hydraulic hammer is slow, tedious and becomes uneconomical when the geological conditions are very tough with a large volume of rock to break. GeoBreak Expanding Grout (NexPand Pro) was used as a cost effective approach without the need for permits or training to use. 1.5” (38mm) hole size was used with 12” – 15” (305mm – 380mm) spacing. After holes were drilled and the slurry was poured, a tarp was used to cover production holes to protect from unwanted moisture to enter the holes during a snowy period. GeoBreak’s Expanding Grout heaved apart the rock allowing for a machine to effortlessly remove the broken material.
Which GeoBreak Products Were Recommended
GeoBreak Expanding Grout Type III was recommended for this rock breaking project.
The expected outcome of using GeoBreak Expanding Grout was to heave apart the rock and allow for a machine to efficiently remove the cracked and broken rock.
GeoBreak Expanding Grout broke the sandstone where a ripper attachment pulled away the broken rock which was loaded and hauled away easily.
Final Thoughts From The Project Contractors
Anytime rock is dug up on a site, whether it be bedrock or boulders, it creates issues that can effect timelines for projects. The rock was large, competent material located where a crane pad footing was being placed. Using a hydraulic hammer would decrease productivity due to the fact there was only one machine (20 ton) on the site that needed to be used in another area. Running a machine and renting a hammer attachment is expensive and time consuming, even more so when you are handling very hard rock. We used GeoBreak’s Expanding Grout to break the rock on the site. No permits, not a dangerous good and same day delivery made this rock breaking a lot more manageable. Two labourers were on handheld rock drills drilling holes with the recommended drilling pattern provided by GeoBreak. Holes were drilled mid-week and the slurry was poured on Friday. The grouted holes did their thing during the weekend while no one was on site with the area tarped off. On Monday the rock was cracked and heaved apart making the use of a ripper attachment to pull away the rock effortless. The rock was handled and dealt with minimal equipment used while continuing to align with project timelines. The non-explosive features of the Expanding Grout allowed us to continue to work without clearing out to a safe distance from traditional blasting operations.