Frequently Asked Questions

What is the correct procedure for grouting a large diesel generator baseplate in an industrial facility in Ghaziabad, and what are the critical quality control checks during and after grouting to ensure the grout fills the void completely and achieves the required bearing strength?

Generator baseplate grouting is a precision operation where the correct procedure and quality control are critical to the long-term performance and alignment of the generator set. For a large diesel generator (typically 500 kVA to 2,000 kVA) in a Ghaziabad industrial facility, the following step-by-step grouting procedure using MC-Grout 100 is recommended. Before grouting, ensure the following pre-conditions are satisfied: the concrete foundation has been poured and cured to at least 80 percent of design strength (minimum 21 days for M25 concrete in Indian summer conditions); the generator baseplate is correctly positioned, levelled (typically to within 0.5 mm over the length of the baseplate using precision steel wedge packs or levelling bolts), and plumb-checked by the mechanical engineer; the holding-down anchor bolts are correctly positioned in their foundation pockets, perpendicular to the base, and the pockets are free from water, dirt, and loose concrete; the concrete surface under the baseplate has been roughened by chipping or grit blasting, blown free of dust, and pre-wetted to saturated surface dry (SSD) condition to prevent the dry concrete from drawing water from the fresh grout. Formwork preparation: erect tight, leak-proof formwork around the perimeter of the baseplate to contain the fluid grout, extending 75 to 100 mm beyond the baseplate edge on all sides. The formwork must be sealed at the concrete surface with foam tape or mortar to prevent grout leakage. Provide a grout inlet opening (funnel) at one end of the baseplate, and a grout vent (overflow opening) at the opposite end to allow grout flow to be observed and to allow air to escape as grout fills the void. Grout mixing: weigh or measure the water and powder accurately per the MC-Grout 100 data sheet (never add water by eye or exceed the maximum water addition — excess water increases bleeding and reduces strength and dimensional stability). Add powder to water (not water to powder) in a clean bucket or drum and mix with a slow-speed drill mixer (400 rpm, double-paddle beater) for 3 minutes until a completely smooth, lump-free, flowing consistency is achieved. Do not mix with a high-speed mixer or concrete mixer — these introduce excess air and reduce grout density. Grout placement: pour the mixed grout continuously and progressively from one end of the baseplate (not from multiple sides simultaneously), allowing the grout to flow across the full length of the void under the baseplate under gravity and the hydrostatic pressure of the grout head in the funnel. Continue pouring until grout exits from the overflow vent at the far end of the baseplate — visual confirmation that the void is completely filled. If grout is slow to flow (indicating a very narrow gap or high resistance), a gentle tapping of the formwork sides may help the grout flow, but do not vibrate the fresh grout (vibration destroys the gas bubble expansion system that provides non-shrink performance). Maintain continuous grout flow without interruption until the overflow vent confirms complete filling. Quality control checks during and after grouting: during grouting, the continuous flow from inlet to overflow without interruption and the absence of visible voids or air bubbles in the exiting grout at the overflow are the primary confirmation of complete void filling. After grouting, check the freshly placed grout surface for bleeding (free water on top of the grout within 30 minutes of placement) — any significant bleeding indicates excess water was added or the grout was over-mixed and air entrained. Significant bleeding is a defect: stop grouting and investigate the cause. Allow the grout to cure undisturbed for a minimum of 24 hours before the holding-down bolts are tightened and a minimum of 48 hours before the generator set is loaded. After curing, drill or core test samples from the overflow grout to check compressive strength (minimum 30 MPa at 24 hours, 45 MPa at 28 days per data sheet), and use a rubber hammer tap test on the perimeter of the baseplate (tapping around the edge while listening for a hollow sound that would indicate a void under the plate) to verify complete contact. If a hollow tap is detected at any location, the grout voids must be filled by drilling and injection of neat MC-Grout 100 at low pressure before the generator is commissioned. Space Arc Engineering supplies MC-Grout 100 and provides technical support for generator, pump, and machinery installation grouting projects across Delhi NCR, Ghaziabad, Noida, and Uttar Pradesh.