HOLCIM (NEW ZEALAND) LTD - CEMENT TERMINALS PROJECT

DEREK WILLIAMS, PROJECT MANAGER CEMENT TERMINALS KEN COWIE CAPITAL PROJECTS MANAGER

Holcim (New Zealand) Ltd SUMMARY

In mid-2014 Holcim (New Zealand) Ltd was granted approval by the Switzerland based Holcim Ltd Executive to proceed with the largest capital investment project undertaken by the local company in recent memory, the construction of two bulk cement terminals with supporting ship unloading and loading equipment.

Holcim Australia and Holcim New Zealand now form part of the recently merged LafargeHolcim Group, the world leader in the building materials industry with a presence in 90 countries and a focus on Cement, Aggregates and Concrete. The LafargeHolcim Group has 115,000 employees operate in 90 countries around the world and had combined net sales of EUR 27 billion in 2014. The merged company objective and commitment is to drive sustainable solutions for better building and infrastructure and to contribute to a higher quality of life.

The CAPEX budget for the Cement Terminals Project is around NZ$ 105 million, with completion scheduled for mid-2016. The project is part of a major business expansion model developed by Holcim New Zealand and defines a new operating strategy for the company going forward, departing from being a cement manufacturer to being a supplier of globally sourced cement with national distribution facilities.

INTRODUCTION

The Terminals Project consists of the construction of two cement storage terminals, one at Timaru, South Island and one at Auckland, North Island. The terminals are similar in design and layout but are not identical. The main structures and equipment consist of two 30,000 tonne capacity DOME silos, two 600 tph pneumatic ship unloaders, a 650 tph ship loader at Timaru and bulk cement tanker loading facilities at both terminals, all supported by equipment auxiliary buildings, office buildings, road-ways, security and dispatch facilities. In July 2014, the key equipment supply contract was signed with Van Aalst Bulk Handling of Netherlands and in August 2014, Downer NZ Ltd. was engaged as the General Contractor. Site work commenced at the Timaru port in September 2014 with site work commencing at the Auckland port in December 2014. The overall project is now more than 50% complete. In this paper we will touch on the bulk handling equipment but the point of focus is directed to the Dome cement storage silos, which to our knowledge, are the first Dome type silos for cement storage in Australasia.

Photo 1. Timaru Port. (pre-commencement) Photo 2. Auckland Port. (pre-commencement)

DOMTEC International of Idaho, United States of America, was chosen as the Dome supplier.

They have a strong track record in supplying and constructing Dome silos for projects all over

the world and have previously constructed Domes for major cement manufacturers including

Holcim in the USA and other countries.

Why a Dome?

There were a number of reasons for choosing a Dome silo instead of the traditional tall

cylindrical concrete silos, steel silos or warehouse type storage silos, economy and speed of

construction being the key factors together but there were others such as:

Control over environmental impact during construction and operation phases due to the

weather tightness and dust control properties of the Dome. The external air-form and the polyurethane foam lining provide excellent insulation and isolation properties, a benefit during construction and operation of the dome.

Dome silos can be fitted with a complete reclaim floor guaranteeing 98% extraction rates.

The dome shape provides a high volume of storage within a relatively small foot print. Dome silo capacities can range from 20,000t to 100,000t.

Photo 3 Timaru Dome

The dome shape is inherently strong because there is no mechanical link between the wall

and roof as the wall and roof is a seamless profile. This provides excellent structural integrity, resistance to earthquakes and severe weather conditions.

The technique of using shotcrete allows efficient and economical construction (eliminating the need for formwork, shoring, and waste). It also enables a rapid construction of the domes regardless of weather conditions since all works are performed inside the dome.

Domes are ideal for combining with pneumatic extraction equipment from ships to dome, to truck loading and can accommodate high volume filling and discharge rates.

DESIGN

Holcim engaged Beca Ltd as their local consultant for support during the Engineering and Design phase along with international partners Holcim Technology of Switzerland, Holcim Trading Group, Spain and civil consultants, Martinez Segovia of Madrid, Spain. DOMTEC designed the Domes and the design peer review was performed by the above mentioned organisations.

The design review process was intense to achieve full compliance with local standards and

also to meet the requirements of our international partners. To meet these, elements around

silo design from the European Norm were taken into account. Considering the design process

was by default, according to American Standard and conducted by a recognised American

Professional Engineer, the review process looked into several other standards, which proved

to be challenging and rigorous in nature. The design codes used for the Dome were:

NZBC - New Zealand Building Code

NZS 1170 series - Structural Design Actions (including seismic effects)

NZS 3101 - Concrete Structures Standard

NZS 3404 - Steel Structures Standard

ACI 318 - Building Code Requirements for Structural Concrete

ACI 313 - Standard Practice for Design and Construction of Concrete Silos & Stacking Tubes for Storing Granular Materials

ACI 334.1 - Concrete Shell Structures

AS 3774 - Loads on Bulk Storage Containers

ASCE 7-10 - American Society of Civil Engineers

EN 1991-4:2006 - Eurocode 1 Actions on Structures Part 4: Silos and Tanks (this code was used by Holcim and its Peer reviewer to compare the design results)

The Dome design was performed by Chris Zweifel, President and Founder of ZZ Consulting

(Idaho) using finite element modelling software (RISA 3d 12.o.z). Dome data

AUCKLAND TIMARU

Dome configuration Hemisphere Cylindrical at the bottom followed by hemisphere on the top

Dome Dimension

Outside diameter 41.2 m 36.0 m

Inside diameter 40.18 m 34.98 m

Shell thickness at base 0.46 m 0.46 m

Dome height 27.5 m (excl. head house) 31.5 m (excl. head house)

Bag filter above the dome 1.58 m 1.58 m

Dome material quantities Shotcrete 1,150m3 of grade 40 MPa 1,470m3 of grade 40 MPa

AUCKLAND TIMARU

Reinforcing 400 tonnes of steel grade 500E 510 tonnes of steel grade 500E

Subsoil data Soft clayey silt for more than 8 m from ground surface.

Reclamation fill overlying Timaru basalt at 5m depth with the basalt layer thickness extending 10 m deep.

Foundation quantities Pile foundation:

259 Continuous Flight Auger (CFA) piles.

Diameter 0.6 m

Length 12.7 m to 13.5 m

960m3 grade 30 MPa concrete

108 tonnes reinforcement Pile cap and ring beam:

0.6 m thick.

840m3 grade 45 MPa concrete.

110 tonnes reinforcement including 854 U shaped starter bars.

Ground improvement:

Excavation down to the top of the Timaru basalt, replaced with engineered fill AP65 material placed in layers of 0.2 m compacted thickness.

8,800 m3 of AP65 material weighing 19.624 tonnes.

Concrete ring beam:

0.8 m thick.

315m3 grade 28 MPa concrete.

71 tonnes reinforcement including 750 U shaped starter bars.

Table 1. Auckland and Timaru Dome data.

CONSTRUCTION

Dome construction passed through several key stages after completing the construction of the foundations and the Dome “ring beam”.

Foundations and ring beam

Details of the foundation design adopted for the Timaru and Auckland sites are described in Table 1 above. The Timaru foundation was completed ready for the Dome to be inflated in February 2015 and the Auckland foundation was completed in July 2015. On completion of the dome foundations and the dome ring beams, preparation was made for the dome “air-form” (outer skin) to be drawn into position and clamped to the side of the ring beam structure.

Photo 4. Timaru ring beam Photo 5. Auckland piled raft

Air-form installation

The folded polyethelene air-form is first placed in the center of the dome then unrolled and clamped into place on the ring beam. The ringbeam is marked at regular intervals to coincide with markings on the air-form and the air-form is attached to the ringbeam by a DOMTEC designed clamping mechanism. Around 25%-30% of the air-form perimeter is left unattached, this is to facilitate lifting and entry of a crane and other mobile equipment under the air-form. All mobile plant emissions are externally vented by fixed vent pipes.

After the mobile plant is located in position near the center of the dome, the air-form is fully clamped to the ring beam and inflator fans are then attached to the air ducts. As the air-form inflation begins, the perimeter is checked to ensure the anchors are tight. The air pressure is raised slowly for some twenty minutes and the pressure is allowed to stabilize as the airfrom takes shape. After the dome is inflated (approximately 1.5 hours) the air pressure is checked at regular intervals to ensure a pressure of 500 Pa is maintained.

Photo 6. Timaru Dome airform inflation

Polyurethane foam insulation Application of the polyurethane foam commences after the dome has been inflated and the access/airlock is in place. With the pressure stabilised, this normally takes 24 hours or more for the dome profile to be fully settled, the polyurethane foam is applied. The foaming equipment includes a pre-heater, which raises the temperature of the chemicals to a temperature of 54 degrees Celsius and a high pressure heated fluid delivery hose system with the foam applicator nozzle. After the first layer(s) of foam has/have been sprayed and prior to placing the reinforcement hangers, the dome is marked with horizontal rings. The distance on these rings is in accordance with the spacing of the structural reinforcing requirements. The foam is sprayed in two layers. Hangers for the structural reinforcement are the placed, along with depth gauges.

Premat installation The premat reinforcement is installed in a grid pattern approximately 900mm o.c.(on center) each way to a height of twenty metres. From twenty metres to the top of the dome the grid pattern is approximately 600mm o.c. As the premat is installed and before proceeding with the next steps, #9 wires approximately 500mm long are attached to the premat steel to allow the structural steel to be attached. These wires are placed on a grid pattern at every other horizontal premat bar and are approximately 1200 - 1500mm apart.

Once the first section of premat is tied, a layer of shotcrete is sprayed after which the first structural reinforcement is tied and then sprayed with shotcrete. This sequence continues towards the top of the dome.

Photo 7. Timaru - Polyurethane layer Photo 8. Timaru – Structural reinforcement Structural reinforcing

After the premat is installed and embedded with shotcrete, two or more horizontal mounting bars are placed for each lift of structural vertical reinforcement. The lowest two or three horizontal structural bars are then installed following the spacing shown on the structural design drawings. When the structural reinforcement is completed up to four metres, it is embeded with shotcrete from the base upwards. As the reinforcement is placed higher in the dome, the rebar diameter is reduced. The structural horizontal and vertical reinforcement are completed to the top of the dome as per structural design.

Shotcrete application

Initially shotcrete is applied to increase the stability of the air-form, this provides strength to the structure in the early stages of construction and supports the installation of reinforcing steel. The first shotcrete is sprayed in thin layers of 6mm to 13mm thick. As the depth increases and concrete cures, the amount of shotcrete applied can be increased to 25mm. Shotcrete starts at the footing spraying deep enough to embed the structural reinforcement up to the back of the bar and continues in application by layering. At this time, the first layer of the ring beam reinforcement around the doors is installed and embeded with shotcrete, followed by the second layer of beam reinforcement and so on. The application of shotcrete is continued, tapering from 25mm – 40mm and building the wall thickness to the dome top, embedding the reinforcement. The wall is gradually layered to full thickness, leaving 25mm – 40mm for the finishing spray.

Photo 9. Timaru Dome - top penetrations

(Dust filters, cement inlet, pressure release valves, level sensor)

Mix design based on DOMTEC proposal:

Mix Code DOMTEC

Description Mix Spec.

Characteristic strength MPa 35

Maximum aggregate size mm 9.5

Target density Kg/m3 2350

Target air content % 5 - 8

Design site slump mm 100 - 150

Water/cement ratio 0.45

GP cement Kg 498

Silica fume Kg 0

Coarse aggregate Kg 60 - 300

Fine aggregate Kg 1175 - 1470

Water reducer ml 650

Super-plasticiser ml 0

Air entrainer ml 0 Table 2. DOMTEC mix design

QUALITY

Prior to any site work, shotcrete test panels were made and testing carried out as per specification.

Photo 10. Core drill of test panel. Photo 11. Test cylinder

DOME EXTRACTION SYSTEM

The Dome silo reclaim system has a fully fluidized floor, with 98% reclaim guaranteed. The Dome silo is filled by the pneumatic ship unloader equipment with the cement and transport air entering the dome via the cement pipeline. The Dome is fully de-dusted and cement is reclaimed from the bottom of the Dome as seen in Figure 1.

Figure 1. Timaru dome reclamation floor

EQUIPMENT

AUCKLAND TIMARU

Ship unloader Supplier: Van Aalst Bulk Handling. Unloading rate: 600 t/h Total unit weight: 226.8 tonnes. Length x Width x Height: 18.2 x 14.3 x 17.7 m Rail travel between manifolds: 126 m.

Supplier: Van Aalst Bulk Handling. Unloading rate: 600 t/h Total unit weight: 200.3 tonnes. Length x Width x Height: 18.7 x 11 x 17.7 m Rail travel between manifolds: 126 m.

Ship loader N/A Supplier: Van Aalst Bulk Handling. Loading rate: 650 t/h

Dome extraction 2 outlets – Convey units Extraction rate: 150 t/h per outlet 2 x GM60S blowers (75 kW each) for central air slides. 2 x GM90S blowers (132 kW each) for dome floor aeration.

2 outlets – Convey units Extraction rate: 325 t/h per outlet 4 x GM60S blowers (75 kW each) for central air slides. 2 x GM90S blowers (132 kW each) for dome floor aeration.

Cement and air pipes

10 cement manifolds – Ø 400mm. 10 air manifolds – Ø 350mm. 3 x VM85 compressors (500 kW each) for cement transport from ship unloader. 2 x VM37 compressors (160 kW each) for cement transport to bulk loading facility.

10 cement manifolds – Ø 400mm. 10 air manifolds – Ø 350mm. 2 x VM85 compressors (500 kW each) for cement transport from ship unloader. 2 x VM85 compressors (500 kW each) for cement transport to ship loader and bulk loading facility.

Cement bulk loading facility

Transfer rate to loading bin: 300 t/h Bin capacity: 300 tonnes Loading spout: 2 x 300 t/h per spout Equipment supplier: IBAU HAMBURG

Transfer rate to loading bin: 300 t/h Bin capacity: 100 tonnes Loading spout: 1 x 300 t/h Equipment supplier: IBAU HAMBURG

Table 3. Timaru and Auckland equipment data

Photo 12. Timaru convey unit Photo 13. Timaru Unloader arm Photo 14. Unloader arm

ENVIRONMENT

AUCKLAND TIMARU Noise Council limit – 55dB LA10 Far side of Quay

Street.

Component Noise

budget Selected design

Utility room 50 dB 47 dB

Control room 45 dB negligible

Wharf equipment 45 dB 39 dB

Dust filters 49 dB 45 dB

Aeration blower 45 dB 42 dB

Truck movements 40 dB 32 dB

Overall 55 dB 52 dB

Council limit – 55dB LA10 Far side of railway corridor.

Component Noise

budget Selected design

Utility room 45 dB 42 dB

Control room 40 dB negligible

Wharf equipment 52 dB 52 dB

Dust filters 45 dB 45 dB

Aeration blower 40 dB 36 dB

Overall 55 dB 55 dB

Dedusting Units

Ship Unloader: 1 unit (104 x Clear edge filtration elements). (40,000 m3/h total flow rate) Dome: 4 units x Windsor PTH66 (6,800 m3/h flow rate each) Convey units: 2 units Donaldson 1006-733 (1,000 m3/h total flow rate) Truck loading bin: 1 unit Windsor PTH66 (6,800 m3/h flow rate) Truck loading chute: 2 units IBAU KN0.22565 (3,600 m3/h each flow rate)

Ship Unloader: 1 unit (104 x Clear edge filtration elements). (40,000 m3/h total flow rate) Ship Loader: 1 unit (55 x Clear edge) filtration elements. (27.000 m3/h total flow rate) Dome: 4 units x Windsor PTH66 (6,800 m3/h flow rate each) Convey units: 2 units Donaldson 1006-733 (1,000 m3/h total flow rate) Truck loading bin: 1 unit Windsor PTH66 (6,800 m3/h flow rate) Truck loading chute: 1 unit IBAU KN0.22565 (3,600 m3/h flow rate)

Table 3. Timaru and Auckland Noise and Emissions mitigation

CONCLUSION

The Timaru Terminal is scheduled for commissioning in December 2015 with operational take over expected in January / February 2016.

The Auckland Terminal is scheduled for completion by July 2016.

ACKNOWLEDGEMENTS

The authors would like to acknowledge the input of the companies, groups and partners involved in the design and peer review process for the Dome.