When it comes to concrete, there are several synonyms for "quality." One such term is "durable," as durable concrete is able to withstand wear and tear over time. "Strong" is another synonym that can be used, as quality concrete should have a strong compressive strength. "Hard-wearing" is also a fitting descriptor, as it suggests the concrete has been properly mixed and cured to create a wear-resistant surface. "Reliable" can also be used to describe quality concrete, as it should be able to stand up to weathering and other external factors. Ultimately, quality concrete is characterized by its durability, strength, and reliability, making it a dependable choice for a variety of construction projects.