Method Statement for Recast Segment
1. INTRODUCTION
1.1 PURPOSE OF THE DOCUMENT
The purpose of this procedure is to define the method to recast the typical segment that need to be carried out on the Long Line and Short Line Typical Moulds. This procedure shall be read together with the Method Statement of Precast Segment Production - Long Line Typical Mould, ref. UMRTL1-CP2-CSYD-CWS-MST-00065 and Method Statement of Precast Segment Production - Short Line Typical mould, ref. UMRTL1-CP2-CSYD-CWS-MST-00035.
1.2 REFERENCES
All reference documents are intended to refer to the last issued revision. • Method Statement - UMRTL1-CP2-CSYD-CWS-MST-00013 “General precasting works at precasting yard” - UMRTL1-CP2-CSYD-CWS-MST-00035 “Precast segment production – Short Line Typical mould” - UMRTL1-CP2-CSYD-CWS-MST-00036 “Geometry control for short line casting method” - UMRTL1-CP2-CSYD-CWS-MST-00016 “Segment concreting works” - UMRTL1-CP2-CSYD-CWS-MST-00027 “Segment curing” - UMRTL1-CP2-CSYD-CWS-MST-00015 “Segment marking” - UMRTL1-CP2-CSYD-CWS-MST-00047 “Segment lifting & handling works” - UMRTL1-CP2-CSYD-CWS-MST-00052 “Geometry Control for Long Line Casting Method” - UMRTL1-CP2-CSYD-CWS-MST-00065 “Precast segment production – Long Line Typical Mould”
2. CONSTRUCTION SEQUENCE
2.1 RECAST SEGMENT ON LONG LINE TYPICAL MOULD
Recast segment for typical segment shall be carried out using match cast segment + bulkhead or using 2 adjacent segments as per the sketch below. CAST SEGMENT BETWEEN MATCH CAST + BULKHEAD: refer to UMRTL1-CP2-CSYD-CWS-MST-00065 for the procedure
CAST SEGMENT BETWEEN 2 ADJACENT SEGMENTS: The recast segment shall be cast as following
• Survey of as-built geometry all segments of the span to determine the dimension of recast segment Sn. Geometry of Sn shall follow the as-built of the quarantine segment. • Bring the segment Sn-1 and position on the long line bed to be used as match-cast segment (M/C). • Mark position of segment Sn+1 based on the as-built information. • Apply the debonding agent to M/C face of segment Sn-1 (segment section area with shear keys) • Place and position the segment Sn+1. • Apply the debonding agent to M/C face of segment Sn+1 (segment section area with shear keys) • Clean external sides forms and apply the mould release agent. • Position & close the external side forms. • Clean soffit and apply the mould release agent. • Rebar cage is store next to the casting location, completed and equiped with corrugated PT duct and spacer blocks. Place the pre-checked rebar cage in the mould. • Install any inserts at web and edge bottom slab (which is not accessible once inner core is closed) • SCC inspection prior to formworks closure. • Shift on rail the portal frame (with inner forms) to casting position. • Final closing of inner forms & external side forms against segment Sn+1 and Sn-1. • Install all inserts at top flange and bottom slab (exposed section) • Final survey check- checking dimension and level Refer to the method statement “Geometry control for long line casting method” UMRTL1-CP2-CSYD-CWS-MST-00052 • Final inspection before casting • Cast long line typical segment & concrete finishing (floating) Refer to the method statement “Segment concreting works” UMRTL1-CP2-CSYD-CWS-MST-00016 • Cure segment Refer to the method statement “Curing of segments” UMRTL1-CP2-CSYD-CWS-MST-00027 • Segment is left on soffit until concrete strength of minimum 25 Mpa prior to lifting from casting bed • Transfer cured segment to finishing area. Refer to the method statement “Segment lifting & handling works” UMRTL1-CP2-CSYD-CWS-MST-00047
2.1.1 CASTING STEPS FOR SPAN P7-11⁄12
2.1.2 CASTING STEPS FOR SPAN P7-12⁄13
2.1.3 CASTING STEPS FOR SPAN P7-13⁄14
2.1.4 CASTING STEPS FOR SPAN P7-14⁄15
List of segment shall be cast on long line typical mould: No. Span Segment 1 P7-11 / 12 S2, S4, S5, S6, S5’, S4’ 2 P7-12 / 13 S1, S2, S4, S5, S6, S5’, S4’, S3’ 3 P7-13 / 14 S1, S2, S3, S4, S5, S5’, S3’, S2’ 4 P7-14 / 15 S2, S3, S5, S6 Total 26 segments 2.2 RECAST SEGMENT ON SHORT LINE TYPICAL MOULD Recast segment for typical segment shall be carried out using 2 adjacent segments as per the sketch below.
The recast segment shall be cast as following: • Survey of as-built geometry all segments of the span to determine the dimension of recast segment Sn. Geometry of Sn shall follow the as-built of the quarantine segment. • Install the soffit table in front of fixed bulkhead • Place segment Sn-1 on the soffit and adjust • Apply the debonding agent to M/C face of segment Sn-1 (segment section area with shear keys) • Lift and position the soffit table to cast position. • Place and position the M/C segment Sn+1 • Apply the debonding agent to M/C face of segment Sn+1 (segment section area with shear keys) • Clean external sides forms and apply the mould release agent. • Position & close the external side forms. • Rebar cage is store next to the casting location, completed and equiped with corrugated PT duct and spacer blocks. Place the pre-checked rebar cage in the mould. • Install inserts (CP3, temporaty PT, lifting holes, etc…) • SCC inspection prior to formworks closure. • Shift on rail the portal frame (with inner forms) to casting position. • Final closing of inner forms & external side forms against segment Sn-1 and Sn+1 • Final survey Refer to the method statement “Geometry control for short line casting method” UMRTL1-CP2-CSYD-CWS-MST-00036 • Final inspection before casting • Cast short line typical segment & concrete finishing (floating) Refer to the method statement “Segment concreting works” UMRTL1-CP2-CSYD-CWS-MST-00016 • Cure segment Refer to the method statement “Curing of segments” UMRTL1-CP2-CSYD-CWS-MST-00027 • Transfer cured segment to finishing area, after lifting strength concrete required reached. Refer to the method statement “Segment lifting & handling works” UMRTL1-CP2-CSYD-CWS-MST-00047 • Segment finishing works Refer to the method statement “Segment finishing works” UMRTL1-CP2-CSYD-CWS-MST-00038 • Remedial works for segment (if needed) Refer to the method statement “Segment remedial works” UMRTL1-CP2-CSYD-CWS-MST-00089 • Storage of segment Refer to the method statement “Segment storage & ½ stacking” UMRTL1-CP2-CSYD-CWS-MST-00053
The recast of segment S1 shall be cast between segment ES1 and S2 according to the procedure in section 2.2. The concrete block shall be used as support for segment ES1 as per the sketch below:
List of segment shall be cast on short line typical mould: No. Span Segment 1 P7-08 / 09 S2 2 P7-09 / 10 S2’ 3 P7-10 / 11 S4 4 P7-12 / 13 S1’ 5 P13-17 / 18 S6 + S5’ 6 P13-19 / 20 S3 + S2’ 7 P13-23 / 24 S4 8 P13-26 / 27 S1 + S2 Total 11 segments
3. ACTIVITY HOLD POINTS
Hold points will be identified in the Inspection & test Plan. Refer to the ITP “Fabrication of Precast Segment ”: UMRTL1-CP2-CSYD-CWS-PLN-00088
4. INSPECTION & RECORDS
All Inspection / check-lists & documents records will be identified in the Inspection & test Plan. Refer to the ITP “Fabrication of Precast Segment ”: UMRTL1-CP2-CSYD-CWS-PLN-00088
