At Kirkpatrick and Hodgson Concrete, a dedicated Quality Assurance/Quality Control laboratory frequently tests mix designs to determine the best aggregate ratio and aggregate-to-paste ratios. Working to gauge the proper formulas reduces the water content of their mixes, determines the amount of coarse aggregate by volume and maximizes their designs without decreasing performance. Kirkpatrick also designs mixes that are “placement friendly” meaning they do not require special mixes for placement by pump truck or tailgate.
Walker Concrete also maintains a QA/QC laboratory and frequently performs a battery of tests on all materials used for concrete in their production facilities. The goal is to also determine the optimum water demand for the materials based on aggregate blends and cementitious blends. Walker's performance mix designs are created to comply with ACI requirements for compressive strength targets along with a specialized aggregate grading system to produce the best workablility for placing and finishing of the concrete.