Use a mastic or adhesive remover as a solvent to remove carpet glue. Heat is another option for the removal of glue remnants without resorting to toxic solvents.
In areas where there are no electrical outlets on the floor, try pouring boiling water, allowing it to sit for about three minutes and scraping the glue with a razor scraper. In areas where water causes a safety hazard, use an iron over newspaper to melt and absorb the glue. Scrub any remnants away with a scrubber sponge before resorting to a solvent. Rinse the concrete with clean water after successfully removing the glue.