Reconstruction of Heavy-Duty Concrete Apron – Warehouse Truck Access

RFQ/OBP427/2025/26

Reconstruction of Heavy-Duty Concrete Apron – Warehouse Truck Access TECHNICAL SPECIFICATION Reconstruction of Heavy-Duty Concrete Apron – Warehouse Truck Access 1.0 PROJECT DESCRIPTION AND DESIGN INTENT The works comprise the demolition, earthworks, construction and commissioning of a heavy-duty reinforced concrete apron at the warehouse entrance and truck manoeuvring area. The apron shall be designed and constructed to withstand: Repeated loading from 30-tonne gross vehicle mass trucks High point loads from axle loads, braking, turning and stationary wheel loads Abrasion from coal spillage and steel-rimmed vehicles Exposure to weather, water ingress and oil contamination The apron shall achieve a minimum design life of 25 years with normal maintenance. 2.0 APPLICABLE STANDARDS (NON-NEGOTIABLE) All works shall comply with the latest editions of: SANS 1200 (where applicable) COLTO Standard Specifications SANS 10100-1 – Structural use of concrete SANS 5863 – Concrete testing TMH1 / TMH10 – Road materials and methods Construction Regulations as amended OHSAct as amended Tshwane Municipal bylaws In the unlikely event where conflict exists, the more stringent requirement shall apply. 3.0 CONTRACTOR’S GENERAL OBLIGATIONS 3.1 The Contractor shall provide all labour, plant, materials, supervision, testing, protection and temporary works necessary to complete the works. 3.2 The Contractor shall: Locate, mark and protect all existing underground and surface services Provide method statements for demolition, compaction, concreting and curing Provide traffic control to maintain safe truck & traffic operations where required. NB: The area serves both staff (pedestrian & those in motor vehicles) and delivery trucks entrance and exit. Be fully responsible for quality control and testing 3.3 No work may proceed to the next stage without written approval by the appointed structural Engineer. OBP shall appoint in writing an independent structural Engineer 4.0 STAGE 1 – DEMOLITION AND REMOVAL OF EXISTING CONCRETE 4.1 Breaking and Demolition Mechanically break and remove all existing concrete slabs, foundations and edges within the defined apron footprint. Care shall be taken not to disturb subgrade beyond required excavation depth. 4.2 Disposal All rubble shall be: Loaded Transported Disposed of at a licensed waste facility Proof of disposal shall be provided to OBP's OHS officer. 4.3 Temporary Protection Adjacent staff parking, security office, structures and services shall be protected at all times. THE CONTRACTOR SHALL ENSURE ADEQUATE PROTECTION TO THE NITROGEN BULK SUPPLY AS WELL AS ASSOCIATED SUPPLY POINTS. OBP shall arrange with the nitrogen gas supplier, Afrox for a delivery hose long enough to reach the bulk supply supply vessel from the refilling truck most likely close to the staff parking area. The positioning of the Afrox delivery truck shall be controlled by Distribution department who shall adopt all reasonable steps to ensure maximum cooperation. After hours deliveries shall be handled by security. Both security and Distribution shall ensure that the area under construction is out of bounds to both foot and mechanised traffic until officially handed over. 5.0 STAGE 2 – EARTHWORKS AND SUBGRADE PREPARATION 5.1 Excavation Excavate to 500 mm below finished concrete level (FCL). Excavation tolerance: ±20 mm. Soft spots, unsuitable material or waterlogged areas shall be removed and replaced at the Contractor’s cost. PLEASE NOTE THIS POINT. 5.2 Subgrade Preparation Exposed subgrade shall be: Scarified to 150 mm Moisture conditioned Compacted to ≥93% Mod AASHTO 5.3 Imported G5 Layer Supply and place G5 natural gravel complying with COLTO. Compacted thickness: 200 mm Compaction: ≥95% Mod AASHTO Layer shall be levelled to ±10 mm tolerance. 5.4 Proof Rolling Proof roll the prepared base with a loaded truck or roller. Any deflection or pumping shall be rectified before proceeding. 6.0 STAGE 3 – FORMWORK, JOINTS AND EDGE RESTRAINT 6.1 Formwork Rigid steel or timber formwork securely fixed. No deformation under concrete pressure. Release agents shall not contaminate concrete. 6.2 Movement Joints (Critical) Provide saw-cut contraction joints at: Maximum 4.0 m × 4.0 m panels Saw cutting depth: one quarter of slab thickness Timing: within 12 - 18 hours after pouring 6.3 Construction Joints Dowels required at construction joints: 20 mm Ø smooth dowels 450 mm long At 300 mm centres Bond breaker on one side 7.0 STAGE 4 – REINFORCEMENT 7.1 Reinforcement Type High-yield deformed bars, minimum grade Y500 7.2 Reinforcement Layout 10 mm Ø bars @ 200 mm centres both directions One continuous layer 7.3 Cover Minimum concrete cover: 50 mm Spacers: Precast concrete or heavy-duty plastic chairs Max spacing: 1.0 m 7.4 Fixing All intersections tied with 1.6 mm annealed wire No loose bars permitted 8.0 STAGE 5 – CONCRETE WORKS (HEAVY DUTY) 8.1 Concrete Specification Ready-mix concrete from approved plant. OBP reserves the right to request an original certificate from the ready-mix concrete supplier. Strength: 30 MPa @ 28 days Maximum water-cement ratio: 0.50 Slump: 75–100 mm Cement type suitable for abrasion resistance 8.2 Slab Thickness Minimum slab thickness: 250 mm (This is essential for 30-tonne trucks; thinner slabs are unacceptable) 8.3 Placement Continuous pour where possible No cold joints without approval Mechanical vibration compulsory 8.4 Finishing Strike off to level Power-float finish Final surface to be: Non-slip Hard-wearing Free of laitance 8.5 Falls and Drainage Minimum fall: 1:60 away from buildings No ponding permitted 9.0 STAGE 6 – CURING AND PROTECTION 9.1 Curing Apply curing compound or Cover with plastic/hessian for minimum 7 days 9.2 Protection No vehicle access for: 7 days (light traffic) 14 days (heavy trucks) Full loading only after 28 days 10.0 TESTING AND QUALITY CONTROL Compaction tests per layer Concrete: Slump tests Minimum 3 test cubes per pour Test results to be submitted to Client 11.0 COMPLETION AND HANDOVER Remove all surplus materials Clean site thoroughly Submit: Test results As-built levels Concrete delivery notes BILL OF QUANTITIES (BOQ – MEASURED WORKS) Item Description Unit Quantity 1 Site establishment, traffic control & safety Sum 1 2 Break and remove existing concrete m² TBD 3 Load, haul & dispose rubble m³ TBD 4 Excavation to 500 mm depth m³ TBD 5 Subgrade scarification & compaction (93%) m² TBD 6 Supply & place G5 (200 mm compacted) m³ TBD 7 Compaction testing Sum 1 8 Formwork to slab edges m TBD 9 Reinforcement Y10 @ 200 mm c/c kg TBD 10 Spacers & tying wire Sum 1 11 30 MPa concrete (250 mm thick) m³ ±142 12 Concrete vibration & finishing m² TBD 13 Saw-cut joints m TBD 14 Dowels at construction joints No TBD 15 Curing & protection m² TBD 16 Testing (slump & cubes) Sum 1 17 Final cleaning & demobilisation Sum 1 12.0 OBP SHALL DEPLOY ONE OF ITS STAFF MEMBERS FROM THE EMU DEPARTMENT TO THE WAREHOUSE APRON AREA WHEN THE WORK BEGINS IN THE INTERESTS OF OBP

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2026/04/02 15:00:00

2026/03/26 11:00:00

RFQ/OBP427/2025/26