Frequently Asked Questions

In a chemical processing plant in Ghaziabad or Noida where sulfuric acid is handled and where pumps are mounted on concrete pedestals that have been attacked by acid spills, what is the correct rehabilitation and re-grouting procedure using MC-Grout EP epoxy grout, and how should the corroded concrete pedestal be repaired before new epoxy grout is applied?

The rehabilitation of an acid-attacked concrete machinery pedestal in a Ghaziabad or Noida chemical plant requires a systematic approach covering concrete assessment, removal of damaged material, repair of the concrete substrate, and re-installation of the baseplate with MC-Grout EP epoxy grout — a process that must be coordinated with the plant shutdown schedule to minimise production downtime. The procedure begins with condition assessment and planning: inspect the concrete pedestal visually and by hammer tapping (hollow sound indicates delaminated or unsound concrete) to identify the extent of acid attack. Acid attack on concrete typically manifests as surface softening, erosion, and etching of the concrete surface (the calcium silicate hydrate and calcium hydroxide in the concrete are dissolved by the acid), followed by progressive loss of surface concrete depth — the affected concrete becomes soft, crumbling, and increasingly porous as the acid continues to react with deeper concrete layers. Take concrete samples for pH testing (acid-attacked concrete shows pH below 10, versus pH 12.5 to 13 for healthy concrete) and for depth-of-attack determination. The depth of concrete removal required is determined by the depth to which the concrete has lost its alkalinity and physical integrity — typically confirmed by phenolphthalein pH spray test on fresh break surfaces (healthy concrete turns pink, acid-attacked concrete remains colourless). Remove all deteriorated concrete by pneumatic breaker or hydro-demolition to expose sound, undamaged concrete throughout the pedestal repair zone. The removal must extend fully under the pedestal footprint — all weak, acid-softened concrete beneath the baseplate must be removed, as any residual softened concrete under the new grout will compress and allow baseplate settlement when the machine is loaded. After removal, assess the rebar condition — acid attack often extends to the reinforcement, and any corroded bars must be cleaned by grinding and treated with MC-Cor 1 zinc-rich epoxy corrosion inhibitor primer before substrate repair. After rebar treatment, repair the bulk of the removed concrete volume with MC-Dur 1300 epoxy mortar (for areas in direct acid contact) or MC-RocTec 222 repair mortar (for areas away from direct chemical exposure), building up the substrate to within 30 to 50 mm of the final baseplate installation level to leave the gap dimension appropriate for MC-Grout EP application. The substrate repair mortar must be cured to full strength (minimum 3 days for epoxy mortar, 7 days for cementitious repair mortar) and the surface must be allowed to dry to surface dry condition before the next step. Formwork and baseplate preparation: install formwork around the repaired pedestal perimeter to contain the MC-Grout EP during pouring. Coat the formwork with a release agent to allow clean stripping after grout cure. Re-position the baseplate on its levelling wedges at the correct elevation and alignment, verified by the mechanical engineer. Mix MC-Grout EP: combine components A, B, and C in the specified ratio (typically A+B first, then add C aggregate and mix until uniform) using a slow-speed paddle mixer. The combined material should be free-flowing (or stiff, depending on the aggregate-to-resin ratio selected for the application — consult data sheet for pourable versus trowel-applied consistency). Pour MC-Grout EP from one end of the baseplate until it appears at the overflow at the other end, confirming complete filling. After the grout has cured to full hardness (minimum 24 hours for initial strength, 7 days for full chemical resistance), strip formwork, remove wedge packs (fill wedge voids with epoxy mortar), and tighten anchor bolts to specified torque. Apply an acid-resistant topcoat (epoxy or vinyl ester coating per the chemical resistance requirement) to all exposed concrete and grout surfaces on the pedestal to prevent future acid attack. Space Arc Engineering provides MC-Grout EP supply and technical support for chemical plant concrete rehabilitation and machinery foundation repair projects across Delhi NCR, Ghaziabad, Noida, and Uttar Pradesh.