SECTION 7: C - STRUCTURAL ENGINEERS SPECIFICATIONS

Transcription

1 SECTION 7: C - STRUCTURAL ENGINEERS SPECIFICATIONS

2 SITE C SHOPPING CENTRE, KHAYELITSHA PROJECT NO 2369 Project Specification Refer all queries to: John Meiring Tel: REVISION P01 john@sutheng.co.za Date: 14 February 2012 Structural, Civil, Mechanical and Electrical Engineers Page 1/6

3 0.0 GENERAL 0.1 All dimensions and levels to be checked on site and correlated with architects drawings and details before construction commences and any discrepancies are to be reported immediately to the architect and engineer. 0.2 All waterproofing details are to be in accordance with the architects specifications and instructions. The structural engineer is not responsible for any waterproofing whatsoever. 0.3 All details and dimensions shown on these drawings are subject to confirmation on site and during construction. 0.4 All construction methods and materials used are to be in accordance with the requirements of sans and sans and all other applicable SABS codes of practice available from the SABS at contact no A non inclusive list follows: (i) SANS 1200 A (1986): General (ii) SANS 1200 AA (1986): Small works (iii) SANS 1200 D (1986): Earthworks (iv) SANS 1200 G (1982): Concrete (structural) (v) SANS 1200 GB (1984): Concrete (ordinary buildings) (vi) SANS 1200 H (1990): Structural steelwork 0.5 It is the contractor s responsibility to ensure that he understands and complies with all relevant engineering drawings and specifications and is adequately experienced to undertake all aspects of the work safely. 0.6 All details and dimensions pertaining to any existing structures are to be confirmed on site by the contractor and the engineer is to be immediately informed of any unexpected aspects pertaining to them. 0.7 Gridlines and site boundaries are to be set out on site by a qualified and professionally registered land surveyor who has adequate professional indemnity cover. 0.8 All products specified for use are to be used strictly according to manufacturer s instructions and specifications at all times. 0.9 The contractor is at all times to be fully responsible for quality control on site ensuring strict compliance with all drawings, details and specifications issued for construction by the professional team The contractor is to comply at all times with all relevant municipal regulations and bylaws in the area of the site and is to ensure that he has a set of approved building plans on site at all times Sealing compounds for the building & construction industry to be in accordance with the requirements of: (i) SANS (1984) sealing compounds for the building and construction industry, twocomponent, polyurethane-base 0.12 Sika-pro 2hp universal one component polyurethane joint sealant or similar approved may be used on all wall joints and must be applied strictly to the manufacturer s specifications and the correct backing cord should be used where necessary Foundations and brickwork construction of single storey buildings, such as gatehouses to be in accordance with SAICE/istruct.e code of practice for foundations and super structures of single storey residential buildings of masonary construction as per NHBRC recommendations. 1.0 EXCAVATIONS AND FOUNDATIONS 1.1 All excavations for foundations (where not piled) to be checked and approved by the engineer before any concrete is cast. This approval will be delegated from the structural engineer to the specialist geotechnical engineer in many cases. All geotechnical input or instructions given by the geotechnical engineer which could have cost implications to the project are to be approved by Sutherland and/or the quantity surveyor prior to carrying out these instructions. 1.2 All foundations to be built on firm in-situ material (not on fill). Structural, Civil, Mechanical and Electrical Engineers Page 2/6

4 1.3 The top level of all foundations to be at least 300mm below final outside ground level or finished floor level, whichever is the lower. 1.4 Assumed safe bearing capacity of soil under foundations 150kpa. (Refer to Geotechnical report) 1.5 All rising foundation brickwork to have continuous brickforce every 2 nd course and cavity to be filled to underside of stepped DPC with 13mm aggregate, 15mpa concrete taking care not to allow any honeycombing. 1.6 All final foundation sizes, depth and details are subject to confirmation on site by engineer. 1.7 The contractor is responsible for ensuring the safety of all deep excavations and for erecting ready fence and or hoarding around the site to prevent entry after working hours and the general safety of the site at all times. 1.8 All foundation excavations to be below any signs of organic material or roots etc. 2.0 CONCRETE 2.1 Concrete characteristics 28 day strength (it not stated otherwise on the drawings): Blinding Unreinforced footings Reinforced footings RC slabs, beams, stairs & landings Surface bed Columns 15 MPa 15 MPa 25 MPa 25 MPa 30 MPa 40 MPa 2.2 Nominal aggregate size 19mm, unless otherwise stated. 2.3 No industrial waste product is to come from industrial facilities co-fired with hazardous waste; 2.4 Confirm that all of the concrete used on site complies with the requirements by identifying all concrete uses in the project and describing the mix and product used. 2.5 Concrete cube tests to be carried out on all pours as per relevant sans 1200 requirements with specific reference to sampling frequency. The contractor should closely monitor these results and problems are to be reported to the engineer immediately. 2.6 All precast concrete suspended slabs to be in accordance with the requirements of SANS 1879 (2004): precast concrete suspended slabs. 2.7 All structural use of concrete to be in accordance with the requirements of: (i) SANS (2000): The structural use of concrete part 1: design (ii) SANS (1994): The structural use of concrete part 2: materials and execution of work. 2.8 All performance tests for precast concrete floors should be in accordance with the requirements of SANS is (1993): Performance standards in building performance test for precast concrete floors behaviour under non-concentrated load 2.9 Curing and protection: After formwork has been removed (SANS 1200 G) and as soon as it is practicable in the opinion of the engineer, all concrete shall, subject to the provisions of (SABS 1200 G) be protected from contamination and loss of moisture by one or more of the following methods: COLUMNS: BEAMS: SLABS: Wrap in plastic sheeting immediately upon removal of formwork, alternatively spray with curing compound. Spray with curing compound immediately upon removal of side shuttering, alternatively leave shuttering in place for 7 days After formwork has been removed (sans 1200 G) all concrete shall, subject to the provisions of of SANS 1200 G (hot weather), be protected from loss of moisture by one or more of the following methods: A) Ponding the exposed surfaces by means of water, (within mortar or concrete kerbs) Structural, Civil, Mechanical and Electrical Engineers Page 3/6

5 B) Continuously spraying the exposed surfaces with water; (impractical in windy conditions) C) The use of an approved curing compound and in accordance with the manufacturer s instruction. WALLS: Spray with curing compound; alternatively, leave the shutters in place for 7 days. Recommended minimum stripping times are as follows: Type of structural member or formwork Type of cement used Portland cement & Portland cement 15 Rapid-hardening Portland Cement Portland blastfurnace cement a) Beam sides, walls and unloaded columns b) Slabs with props left underneath c) De-propping mpa 15mpa 15mpa d) Post tensioned flat slabs Min. Strength Min. Strength Min. Strength e) Beam soffits with props left underneath, and ribs of a ribbed floor construction f) Slab props including beam props g) Cantilevers Holes, chases, and fixing blocks: no holes or chases, other than those shown on the drawings or approved by the engineer, shall be cut or otherwise formed in the concrete. The manner of attaching fixtures to be embedded in the concrete shall be subject to approval by the engineer Permissible deviations appropriate to the degree of accuracy ll (Commonly called good work ) is required for linear dimensions, position, verticality, level, squareness and bow (refer to SANS 1200) 2.12 All exposed corners for columns and walls in the basements to receive 30mm chamfers and all columns in brickwork walls to have no chamfers Excess concrete such as, burrs, spillage, overcast, etc. Is to be rubbed down smooth and have a similar colour variation between the different concrete elements. 3.0 REINFORCEMENT 3.1 All reinforcement to be checked and approved by the engineer before casting concrete. 3.2 The engineer is to be given a minimum of 24 hours notice before reinforcement inspections and the work needs to 100% complete when he arrives for the inspection. 3.3 Bending schedules and fixing details for reinforcement are given separately at a later stage. Structural, Civil, Mechanical and Electrical Engineers Page 4/6

6 3.4 Minimum concrete cover to reinforcement (unless specified differently in bending schedules or drawings): Foundations (bases) Beams (internal) Beams (external) Columns Slab soffits and tops Slab edge 50mm (see bending schedule) 30mm 40mm 30mm 30mm 40mm 3.5 The contractor must take particular care to ensure that the specified concrete cover to all reinforcement has been attained throughout and all rebar is securely and neatly fixed before the engineer is called to undertake rebar inspections. 3.6 Reinforcement allowances for concrete work are as follows for initial estimating purposes: Bases Columns Beams Slabs 70kg/m³ 160kg/m³ 150kg/m³ 120kg/m³ 3.7 All concrete is to be mechanically vibrated and compacted. 3.8 On multi-storey buildings back propping is to be agreed with engineer in detail and no stripping is allowed before permission is obtained from the engineer. 3.9 It is the contractor s responsibility to ensure that all reinforcement and cover blocks are correctly and accurately fixed, and remain in place during pouring The engineer will not be responsible for any concrete cast where he was not notified to carry out a rebar inspection visit. 4.0 BRICKWORK 4.1 Precast lintols with a minimum of 4 courses of brickwork over with continuous brickforce in the lower 2 courses (extending 150mm either side of opening) over every opening not exceeding 3m. 4.2 All brickwork is to be connected to reinforced concrete columns by means of galvanised hoop-iron straps shotfired into concrete through 10mm jointex at a minimum of every 4 th course. Hoop-iron is to be built a minimum of 300mm into brickwork. 4.3 Two continuous layers of brickforce are to be laid in the first two courses below the first floor slab soffit level and also the eaves wall plate level. 4.4 All brickforce to have at least 300mm overlap at all joints. 4.5 Brickforce is to be laid in every 5 th course of brickwork. 4.6 Brickforce longitudinal reinforcement to have a minimum diameter of 2.8mm 4.7 Wall ties 2, 5 ties/m², as per SANS in standard cavity widths up to 75mm. All cavities greater than 75mm are to have vertical twist ties. 4.8 All brickwork to comprise bricks. Built in accordance with SANS 10164, in class 2 mortar. 4.9 Cement bricks to have a nominal compressive strength of 14mpa for foundation and load bearing walls in accordance with SANS Bricks to be at least 28 days old when delivered to site. Cement bricks and blocks are to be sans approved Thickness of foundation brickwork for various different heights required due to site conditions to be in accordance with the relevant section of SANS All internal non-load bearing brickwork to stop 20mm below soffit of slabs and sealed in accordance with the architectural and acoustic engineering specifications Chasing depth limits: Vertical chases in solid units should not exceed one third of the wall/leaf thickness. Structural, Civil, Mechanical and Electrical Engineers Page 5/6

7 Horizontal chases should not exceed one sixth of the wall/leaf thickness. Horizontal chasing is to be avoided where possible Movement joints to be allowed for as per the Engineer and Architect s requirements. 5.0 TEMPORARY SUPPORT WORK 5.1 It is the contractor s responsibility to ensure the adequacy of temporary support work at all times. This responsibility to include, interalia, lateral bracing, warning signs and public protection measures. 5.2 Support work to remain in place until new support beams are in place, and caulked and in the case of new cast in-situ concrete support, cured for a minimum of 14 days. 6.0 STRUCTURAL STEELWORK 6.1 Steelwork materials, manufacture and erection to be in accordance with the standardized specifications of civil engineering construction sans and SANS 1200h 6.2 Structural steelwork to be grade 355 JR as per SANS code. 6.3 Refer to project specification for painting requirements and surface preparation as well as the relevant SABS code of practice. 6.4 For galvanised steelwork, the galvaniser shall provide a certificate of conformance. 7.0 STRUCTURAL TIMBER 7.1 Gang nailed roof trusses to be designed by Mitek or similar approved. Mitek is to inspect erection of the roof trusses and sign off that they are satisfied with the erection. 7.2 All roof trusses are to be tied down by means of galvanised hoop-iron built in securely at least 6 brick courses below wallplate as per SANS All South African pine timber specified is to be grade 5 unless specified otherwise. 7.4 Galvanised steel strap anchors shall be taken up over the top of the rafter or tie beam, bent down on either side and nailed down from both sides, or galvanised roof ties shall be made up of two strands of wire which shall be taken up on either side of the rafter beam, twisted together so as to have no slack, but not so as to overstrain the wire, and the free ends then nailed down to prevent untwisting. 7.5 Any roof truss, rafter or beam shall be fixed to any wall by using one of the following types of anchors: (i) (ii) (iii) Type A: two strands of 4mm galvanised steel wire; Type B: 30mm x 1,2mm galvanised steel strap; Type C: 30mm x 1,6mm galvanised steel strap. 8.0 SURFACE BEDS AND SCREEDS 8.1 All screeds are to be minimum 30mm thick and jointed into panels of maximum size of 4mx4m. Joints should also be provided over joints in the slab/surface bed below. Joints in screed are to extend at least halfway through the thickness of the topping. The aspect ratio of the panel sizes should be no more than 1:1.2. Tile joints should coincide with the screed joints and sealed with polyurethane sealant. 8.2 The contractor shall provide results of compaction testing of the earthworks layers for approval, if requested by the engineer, before casting surface beds. A minimum requirement is at least 100mm of approved hardcore or 300mm of approved granular fill compacted to a minimum of 98% mod aashto. 8.3 All surface beds to have a minimum thickness 350 micron DPC below them with adequate laps and turned up to the full depth of surface bed as bond breaker against all brickwork on all sides. Top of surface bed level to be a minimum of 150mm above the final outside levels as per SANS Structural, Civil, Mechanical and Electrical Engineers Page 6/6