Project Details
Concrete path construction and structural column repairs at Musgrave Hill State School, carried out in accordance with engineering plans prepared by PACM Engineers.
| Project Size: | 40m² concrete path, 16m² slab reinstatement, 110 litres of concrete repair (max) |
| Project Duration: | 3–4 Weeks |
Project overview
Structural deterioration to existing concrete columns at Musgrave Hill State School required urgent remediation to restore structural integrity and prevent further damage. Exposed and corroded steel reinforcement within the columns, combined with a deteriorated concrete path, necessitated a comprehensive repair programme across multiple areas of the A Block Lower Floor.
CRS was engaged to carry out concrete path construction and structural column repairs across two separate column locations. Works were completed in accordance with engineering plans P723-SK1 to SK3, prepared by PACM Engineers (Rev 1, dated 23/07/2025), and involved the use of Sika 910 corrosion treatment, Sika 436 repair mortar, and Patchguard 500 sacrificial anodes to protect the reinforcement from future corrosion.
Project scope
Section 1: Preliminaries
Site works included full site establishment, site cleaning and trade waste disposal off site, general waste removal using skip bins, photographic records and progress reports provided to the Owner and Structural Engineer throughout the works period, insurance and licence compliance, a dilapidation report prior to commencement, and full access, protection, materials handling, site supervision, and OH&S management.
Section 2: Concrete Path Construction
Works were carried out in accordance with Plan P723-SK1 as prepared by PACM Engineers. The existing subgrade was removed to a depth of 300mm using an excavator and skid-steer loader across a total area of 40m². New CBR15 subgrade material was then supplied, placed, and compacted. Edge boards were installed, steel reinforcement was placed and tied, and N32 concrete was poured and finished to a 100mm thick path over the 40m² area. A line pump was used to pump the concrete, and saw cutting was carried out upon completion of works. This section was estimated to take 5–6 days to complete.
Section 3: Column Repair at Section 1
Works were carried out in accordance with Plan P723-SK2 as prepared by PACM Engineers. Damaged sections of concrete were cut out to expose the steel reinforcement to the existing concrete column. Steel reinforcement bars were cleaned where possible and treated with Sika 910. New steel reinforcement bars were supplied, installed, and treated with Sika 910. Patchguard 500 sacrificial anodes were supplied and installed, with all anodes tested prior to filling. Repair areas were cleaned, primed, and infilled with Sika 436 repair mortar. A maximum of 40 litres of concrete repair and 2 anodes were allowed for Column 1. The repair area was formed and poured. This section was estimated to take 3–4 days to complete.
Section 4: Column Repair at Section 2
Works were carried out in accordance with Plan P723-SK3 as prepared by PACM Engineers. The existing floor slab was saw cut around the column to provide a 2m clearance zone, with an estimated 16m² of slab removed. An excavator was used to remove the slab on ground and dig out existing soil to expose the top of footing, with the top of footing assumed to be 1m below the existing floor slab. Existing soil was battered and stored on site for reinstatement. Damaged concrete was cut out to expose steel reinforcement, which was cleaned, treated with Sika 910, and supplemented with new reinforcement bars. Patchguard 500 sacrificial anodes were installed and tested prior to column infill. Repair areas were cleaned, primed, and infilled with Sika 436 repair mortar, with the column formed and poured 40mm larger to the face to ensure adequate steel reinforcement cover. Soil was reinstated and compacted, and SL82 mesh reinforcement was placed prior to pouring and finishing 100mm thick concrete over the 16m² saw cut area. A maximum of 70 litres of concrete repair and 4 anodes were allowed for Column 2. This section was estimated to take 8–10 days to complete.
Warranty and Timeline
- Estimated Duration: 3–4 weeks from commencement
- Lead Time: 2–4 weeks from date of acceptance
- Tender Validity: 90 days
- Inspection Scope: A Block Lower Floor area only
- Workmanship Warranty: 2 years from date of completion
- Structural Warranty: 6 years from date of completion
- All materials and equipment carry the associated manufacturer’s warranty.
