Frequently Asked Questions

For a 500 MW power plant turbine generator base plate grouting project at a Delhi NCR power station, what performance specification should the project engineer write for the precision grout, and why does MC-Grout SV meet these requirements?

The specification for precision grout in a turbine generator base plate installation at a major power plant is one of the most critical and tightly controlled grouting specifications in industrial civil engineering. The turbine generator set is a piece of rotating machinery operating at high speed (typically 3,000 rpm for 50 Hz synchronous generators) with very large rotating mass (rotor mass in 500 MW generators typically 100 to 200 tonnes) and shaft alignment tolerances measured in hundredths of a millimetre. The quality of the grout bed under the base plate directly determines the shaft alignment stability, vibration characteristics, and long-term operational performance of the turbine. A grout bed with voids (incomplete filling under the base plate), a grout that has shrunk away from the plate (leaving a stress-concentrating gap under loaded regions), or a grout that is too weak (cracking under the alternating compressive and tensile stresses from rotating machinery vibration) will cause misalignment, vibration transmission to the foundation, and potential shaft damage — consequences that involve extremely expensive remediation and lost power generation revenue. The performance specification for precision grout in a 500 MW turbine generator base plate installation should include the following minimum requirements. Compressive strength: minimum 50 MPa at 28 days (to exceed the contact stress under the base plate from turbine deadweight plus dynamic load amplification factor of 1.5 to 2.0) — this requirement rules out standard precision grouts in the 30 to 40 MPa range. Non-shrink performance: no plastic shrinkage — verified by the sleeve test or ASTM C1090 standard — to ensure full contact under the base plate. Self-levelling fluidity: Hagermann flow greater than 270 mm — to ensure the grout fills the full underside of the large base plate area (typically 3 to 5 metres long by 1 to 2 metres wide) in a single gravity pour without vibration or pumping. Chloride content: less than 0.05 percent by mass of cement — to protect the anchor bolts from chloride-induced corrosion. Temperature compatibility: grout must be suitable for placement at Indian ambient temperatures of 20 to 40 degrees C. MC-Grout SV meets or exceeds all of these requirements: compressive strength exceeding 60 MPa at 28 days (10 MPa above the minimum specification), non-shrink by gas-generating expansion mechanism, Hagermann flow exceeding 300 mm (above the 270 mm specification requirement), chloride-free formulation, and factory-tested performance at temperature ranges applicable to Indian site conditions. For the installation procedure, the grout specification should also include details on subbase preparation (shotblasting to Sa 2.5 or scarifying to ICRI CSP 5-6), anchor bolt clearance inspection, pre-installation moisture check of the concrete pedestal (SSD condition before grouting), mixing equipment (forced-action paddle mixer — no transit mixer), batch size limitation (maximum 2 bags at 30 degrees C ambient — 1 bag at above 35 degrees C), grout header box design (minimum 100 mm head above the base plate underside at the pour point), vent location (on the opposite long side from the pour point), and curing procedure (wet hessian and polythene for minimum 7 days, surface temperature maintained below 40 degrees C). Space Arc Engineering provides technical advisory support for precision grouting projects in power and heavy industry across Delhi NCR and Uttar Pradesh — contact our technical team at +91 9999155255 for project-specific grouting system design and product supply.