ACI 351.1R

Description / Abstract: This report provides an overview of current practices for grouting to support equipment and machinery. Recommendations are provided for those portions of the grouting operation where a consensus could be developed among knowledgeable manufacturers and users. Various approaches are outlined for areas where opinions differ. Many statements and much of the information contained in this report are based on published manufacturers' data and observations and practical experience by technical representatives and users. There is little current published research available at this time, but the information in this report is the most current information available. This report describes materials and installation methods for grouts used as load-transfer material between machine or equipment bases and their foundations. Characteristics of the placed material, test methods for forecasting their long-term performance, and installation procedures are included. The information may also be appropriate for other types of applications where filling of the space between load-carrying members is required, such as under column baseplates or in joints between precast concrete elements.

Machinery and equipment that have precise tolerances for alignment or require uniform support cannot be placed directly on finished concrete surfaces. Both the concrete surface and the machine base have irregularities that result in alignment difficulties and bearing load concentrations. For this reason, machine bases or soleplates are aligned and leveled by shimming or other means, and the resulting space between the machine base and the foundation is filled with a load-transfer grout material. The load-transfer grout materials most frequently used are nonshrink cementitious grouts and nonshrink epoxy grouts.