Start with blended cement. PPC and PSC replace 30 to 50 percent of the clinker with fly ash or slag, and the concrete is often more durable for it.
Next, specify strength at 56 days instead of 28 where the programme allows. Blended cements keep gaining, so you can use less cement for the same final strength.
Finally, order accurately. Over-ordering is the quietest source of waste on any site. Our Coverage guide and sales engineers can help.