Nobody can really tell for sure what will work but you - we haven't got your particular glue handy to test.
Pressure washer is a good bet. You have it, so try it. If at first it doesn't succeed, try a narrower nozzle.
A wire brush might also work. If the glue is brittle, a silicon carbide grinding block may work - or you might rent a terrazzo-grinding machine at a tool rental store for a more industrial approach to grinding it clean, especially if it's a large area.
Muriatic Acid probably scares you as terrible for you and pets, but if you keep the pets off while using it, dress properly, and rinse throughly and then spray water and baking soda mixture around (not actually required, but worth it if it gives you peace of mind) it can be safe and effective at cleaning up concrete.