PROCEDURE GROUTING APPLICATION WORKS
PROCEDURE GROUTING APPLICATION WORKS
This method statement covers the grouting application for equipment foundations, precast concrete and structural foundations including all operations necessary for the surface, formworks, proper mixing, placing, finishing and curing for non-shrink cementitious grouting.
Grouting application shall be in accordance with Standard Drawing for Grout and Surface Preparation unless otherwise specified in issued for construction drawings.
TOOLS AND EQUIPMENT FOR GROUTING WORKS
- Tools and equipment should be in good condition and must be checked by Safety Officer / Mechanical Supervisor prior to use in the construction area. These included but not limited to the following:
- Resin mixer drill and/or Spiral Paint Mixer
- Bagger mixer (depends on quantity required)
- Grout mixers with container suitable for quantity required
- Drill mixer
- Mixing paddle
- Pan mixers or rectangular container
- Pushing tools (use to assist the grout to fill for far location)
- Caulking guns
- Finishing trowel
- Wheel-borrow, bucket
- Survey instrument
- Starret level
- Air compressor
- Formworks with releasing oil
- Vacuum cleaner
- Power stiff bristle brushes
- Hand tools
- Electric/Manual saw
- Grouting materials shall be in accordance with the project specification Section 3.5 for Epoxy grout and Section 4.5 for cementitious grout. Only approved COMPANY grout products shall be used.
- All materials shall be delivered to job site in original unopened packages and shall be stored in accordance with the manufacturer’s recommendation.
- Grouting materials shall be stored out of direct sunlight, clear of the ground on pallets protected from rainfall. Avoid excessive compaction.
- The grout shall be stored, mixed, placed at temperatures recommended by manufacturer.
- Confirm that structural and equipment foundations released for grouting has reached the required strength or has cured the length of time as per project specification. For precast concrete column and foundation; precast column shall be aligned and accepted. Prior to grouting; the base plate level must be approved by COMPANY.
- Secure valid Work Transfer Sheet from civil/structural and mechanical group signed by respective department confirming that the equipment and/or structure is ready for grouting.
- Secure a valid work permit before starting any grouting works.
- Prepare grout area in accordance with the extent of grouting as shown in Grouting Method “Standard Drawing for Grout and Surface Preparation”
- Contact surfaces of grout shall be chipped/rough to remove all laitance and weak surface materials. A sound and clean substrate shall reveal.
- Concrete chipping and removal must not be performed with heavy tools such as jackhammers as they could damage the structural integrity of the foundation. A chipping hammer with a chisel bit is the preferred tool for this purpose.
- When surface preparation is completed, remove all debris from bolt pockets by vacuuming. For foundation’s top surface area, use power wire brushing to remove loose contaminants followed by blowing of oil free air using air compressor. All surfaces should be thoroughly cleaned to ensure a strong bond develops between interfaces.
- The underside of base frame equipment shall be clean, dry and unpainted to allow grout to bond.
- A minimum of 25mm of concrete must be removed for damaged concrete down to exposed fractured coarse aggregate.
- Bolts and sleeves shall be with seal and dry.
- Ensure the base frame or skid is properly positioned and leveled.
- Formworks shall be built of materials of sufficient strength and securely anchored and sealed to withstand the liquid head and forces developed by grout during placement. With sealant to avoid grout loss and dimension to permit grout placement.
- Grout forms shall have chamfer strips at all vertical corners and at the horizontal surface of grout.
- Bond breaker compatible with manufacturer recommendations shall be applied to surfaces of formworks and temporary fixing pieces to facilitate removal after the grout has hardened.
- Confirm that proper number and size of air relief holes in base plates were provided to prevent voids.
- Cover grouting work area on floor with plastic to protect the floor.
Placement of Grout
- Grout shall be used under all base plates of equipment and structures, precast concrete structure where a uniform bearing surface is required for transfer of loads into the foundation. Placement of grout shall be as per manufacturer’s recommendations on mixing temperature.
- Where applicable, the grout shall be chamfered to the lower edge of the base plate.
- Non-shrink Cementitious Grout
- Non-shrink cement based grout shall have the properties as per specifications.
- Formworks dimension shall be as per manufacturer’s recommendation to allow a pressure head to build up facilitate flow and full coverage. The top of formwork should be at least 25mm above the underside of the base plate. Before fixing the last piece of formwork, remove all dirt and debris from within the area to be grouted.
- Saturate the concrete within the formwork with potable water for 24 hours prior to grouting. Surface shall bed amp but free of standing water prior to grouting.
- Mix the initial batch of grout materials into one bagger mixer and/or plastic bucket (depends on required quantity) and mix as per manufacturer standard. Mix until a smooth, uniform, lump free consistency is achieved.
- Pour the grout immediately after mixing into the prepared area in such a manner that the grout has the shortest distance to flow. Pour the grout in one direction to prevent trapping of air and continuously to avoid segregation, bleeding, or premature initial set.
- Fill all the bolt pockets with grout before pouring the rest of the under plate with grout.
- Cure the grout with potable water using water-saturated burlap in the duration of 7 days.
- Grout sampling shall be taken by approved third party for compressive testing.
- Formworks can be removed after 24 hours or as per manufacturer’s recommendation. Removal of formworks shall be properly done to avoid surface damage.
- Permanent shims shall have a minimum distance from the edge of base plate equal to the thickness of the grout pour.
Testing of Grout Works
- Non-shrink cementitious grout’s compressive strength shall meet the requirements of ASTM C1107 and shall be at least of 34.5 Mpa (5000 psi) at twenty-eight (28) days and not less than the 28-day compressive strength of foundation concrete and a minimum working time of sixty (60) minutes when tested in accordance with ASTM C 191.
- Expose grout shall be coat with an approved curing compound to retain moisture during curing.
- Finishing and Clean-up
- The grout is of self-leveling consistency; however, a steel trowel damped into solvent might be needed to finish the grout surface.
- Remove excess grout or drops; the leftover grout materials shall be made into solid waste for proper disposal as per COMPANY. Clean transport buckets and other equipment for next application jobs.
- Good housekeeping shall be maintained after completion of application.
- Repair/replace of Cracked Portion
- Cracked/damaged portion shall be manually chipped and removed, the chipped surfaces should be thoroughly cleaned by air and washed with water to ensure a strong bond between surfaces; then apply grouting materials.