Magazine of the Irish Concrete Federation June 2009

Concrete Built is Better Built concrete today - ics awards From the Editor Irish Concrete Society Awards

he winning entries at the Irish Concrete Society’s Awards, Twhich took place recently, came from all over Ireland and ranged from private houses to community buildings to road, rail and harbour developments. Concrete School Buildings The Awards Evening has been running for 30 years and is a highlight in the construction industry’s calendar. The Awards In late 2008, Labour Party spokesman on Education, Ruairi recognise excellence in both design and construction in Quinn, raised a question in the Dail in relation to the number of concrete. The jury reviewed a total of thirty one projects ‘prefab’ school buildings in use. Addressing the Minister for entered in three categories. The jury were impressed by the Education and Science, Batt O’ Keefe, he questioned the rationale quality and high standard of detail exhibited by all entries behind a reliance on such temporary accommodation. entered in three categories – Elemental, Building & Infrastructure. They also made an award for the use of concrete RTE’s Primetime programme recently raised the same issue, in a sustainable context. reporting that reliance on light gauge steel prefabs had spiralled in recent years. In many schools, temporary accommodation is the norm and in some instances teachers are teaching in the same temporary classrooms in which they themselves were taught as students. Some schools are comprised entirely of steel prefabs and have been promised permanent accommodation for many years. In 2008 alone, the rental costs to the taxpayer for steel prefabs reached €50 million, almost 13 times the €4 million spent in the year 2000. An additional spend of €35 million was made on ‘other temporary accommodation’.

School managers interviewed on the Primetime programme called for the provision of proper ‘bricks and mortar schools’ which they said could be provided at a lower cost than the temporary rented accommodation. Steel prefabs they argued are designed as temporary accommodation only and are ‘too hot in summer and too cold in winter’.

There is an ongoing national debate as to where government capital spending should be concentrated and there is no shortage of ‘good advice’. However, the fact that enormously expensive rental accommodation can be taken out of the equation with the provision of a more permanent form of accommodation, lends strength to the argument that the schools building programme should be further accelerated.

From the perspective of the concrete industry, the long overdue replacement of light gauge steel prefabs with masonry/precast concrete built classrooms, makes good sense at the present time. Thermal mass, sound and vibration absorption, fire resistance, inertness and incredible durability, makes concrete by far the best structural option.

Brian Ó’Murchú Marketing & Technical Manager. Lake House, Co. Kerry

Winner – Elemental Category Lake House, Co. Kerry was the Elemental Category Winner where the jury considered 9 entries. The winning scheme demonstrated an excellent understanding of the importance of attention to detail at all stages through design to construction. It is evident that Client, Designers and Contractor worked as a

concrete today 2 concrete today - ics awards

Lake House, Co. Kerry Project Team

Overall Award (Infrastructure) Award- Caladh Mór Sheltered Harbour Development Client: Galway County Council Engineer: RPS Consulting Engineers Contractor: SIAC Construction Major Supplier: Cairealacht Chill-Bhride Teo

Elemental Award – Lake House, Co. Kerry Client: Private Architect: Clancy Moore Architects team. The aesthetic and structural qualities Engineer: Malachy Walsh & Partners of the concrete remain exposed in the Contractor: S & T O’Shea Contractors completed element and the result is a Major Supplier: John A Wood pleasant blend where old and new integrate seamlessly. Building Award – Sean O’Casey Community Centre Client: Docklands Development Authority Winner – Building Category Architect: O’Donnell + Tuomey Architects Sean O’Casey Community Centre was the Engineer: Casey O’Rourke Associates Building Category Winner from amoung Contractor: PJ Hegarty & Sons 13 entries were considered. The quality and Major Supplier: Roadstone variety of entry impressed the jury. The winning entry was chosen as it exudes simplicity and clarity of detail which is achieved using a minimal palette of materials – primary concrete. This building illustrates how simple ideas well resolved can make a strong statement of community spirit.

Building Award

Sean O’Casey community centre

Pictured above Back Row L to R, Paddy Smith (Roadstone), Cyril Sweett (QS), Edward Hanlon, Darren Gavin (PJ Hegarty) Front Row L to R, Susan Cogan (Dublin Docklands Development Authority), John Casey (Casey O’Rourke), Laura Harty (O’Donnell + Tuomey)

Sean O’Casey community centre

concrete today 3 concrete today - ics awards

Caladh Mór sheltered harbour development, Inis Meáin, Aran Islands

Overall Winner of the 2007 Irish Sean De Courcy Student Award make a commendation in addition to the Concrete Society Awards The award is in honour of the late Sean De above award. The Overall Winner was in the Courcy, Professor of Engineering at UCD, Infrastructure Category where there were 9 Chairman and Friend of the Irish Concrete The Highly Recommended entries. The jury considered that the Society, Author and Historian. The Sean Project is: winner demonstrates how in adverse de Courcy Award is given to an “Formwork Striking Times of GGBS conditions nature’s raw materials can be undergraduate for the best final year project Concrete using Temperature Matched excavated, reconstituted with the addition relating to concrete. The winning project Curing” by Sean Griffin of DIT Bolton of cement to form concrete elements and was entitled ‘Development of the flexible Street. reassembled in the same place in a way that concrete arch system’ and has been won absorbs the forces of nature and provides a by Ross Johnston of Queens University European Concrete Award welcome place of refuge and safety. With a Belfast. An Irish Entry in the European Concrete commendation in the Sustainability Society’s Network Awards Scheme received Category, the overall winner of the Irish The project was awarded on the basis of: an “Honourable Mention” in the Building Concrete Society Wards 2008 is ‘Caladh • This thesis has relevance in a Category. The entry was The Sillogue Mór Sheltered Harbour Development, Inis developing area. Water Tower, which was a winner in the Meáin, Aran Islands’. • It deals with an efficient and sustainable Society’s Awards scheme in 2007. form of construction which in our view Presentations were made to representatives moves the subject area forward. of the clients and contractor who attended • It is practical in its application, the the Awards Evening. subject was well researched and the report continually made reference to Project Team the application of the research and Client: Dublin City Council testing involved. Engineer: McCarthy Hyder • The report was well presented in a clear Consultants logical manner and was of very high Architect: Michael Collins & quality. Associates Contractor: John Craddock Ltd This year, due to the very high quality of Major Supplier: Roadstone the submitted reports, the Jury decided to

concrete today 4 concrete today - techrete

Techrete’s New HQ & Production Facility Balbriggan, Co. Dublin

Space between office building and canteen

concrete today 5 concrete today - techrete

Techrete’s office building, canteen and factory

echrete have completed the construction for ‘self finishing’ with precast concrete and Tof a new ‘state of the art’, purpose built, also for incorporating services within the production facility and head office on a 15 precast units. acre site in Balbriggan, North County The construction of the entire complex Dublin. The company have invested €25m took less than 12 months, commencing in in the new development. October 2007 and completed and The move from the original premises in operational in September 2008. Howth, Co. Dublin presented a unique The new facility comprises a production opportunity to design a series of buildings hall, ancillary offices, product yard, canteen to showcase a wide range of precast and headquarters office building. The products. The emphasis throughout has overall development is in excess of been to create a high quality development, 10,500m2. Careful consideration went into but at reasonable cost, using the principles the planning and layout to ensure of repetition and simplicity of detail and maximum efficiency, from delivery of raw construction. material to batching plant, casting tables, A number of innovative precast concepts finishing and storage. A landscaped berm were incorporated in the design to produce was located on the eastern boundary to act a complex of buildings that set a new as a buffer to the houses along White Hart benchmark for industrial buildings. The Road. complex is visually attractive and was built with remarkable speed and within budget. Production Hall The designers, JSA Architects, were The new 9,100m2 L-shaped production hall, already experienced in precast concrete is mainly single storey, except for a two storey design, however, the opportunity to work section containing the production office and with one of Europe’s leading precast staff welfare facilities. The building has been cladding manufacturers provided a unique constructed using a precast concrete frame, opportunity to demonstrate various aspects Techrete Office’s: clad with industrial precast concrete of precast. The designers placed a particular Precast columns and ceilings sandwich panels in contrasting colours of emphasis on demonstrating the potential grey and white, with an exposed aggregate

concrete today 6 concrete today - techrete

Techrete’s production hall finish. The panels are 225mm thick with a As part of the design process, the contrasting panel colours were used 60mm insulated core. On one elevation of architects studied several buildings in throughout the complex. The simplicity the building, the panels also provide a Europe. The result was a cladding panel of the panel design facilitated installation structural support to one end of the 50m system that was elegantly proportioned, rates of 250m2 per day. The cladding span external Goliath gantry crane. visually attractive and economical. Two system is particularly robust, well insulated, resistant to impact and fire and has excellent sound attenuation properties. Attention was also paid to the environmental impact of the development. Various features were incorporated including the recycling of grey water from the roof and hard standing areas, recycling of all waste concrete and an effluent treatment plant to control the PH and solid contents of all effluent.

HQ Office Building And Canteen The office building and canteen are fully precast buildings with a highly polished concrete surface to the outside. The canteen is located between the production hall and the office building creating a number of informal spaces and a ‘people friendly’ pedestrian zone linking the office building and the production hall. The loadbearing elements consist of internal Product storage area: Precast cladding panel precast wall panels and external precast concrete sandwich panels.

concrete today 7 concrete today - techrete

The office building is positioned and designed to be the main focal point addressing the new distribution road serving Balbriggan. The architects introduced a series of interlocking geometric shapes with projecting fins to the outer face of the office block, which exploit the inherent strength of the wall panels and make for interesting work spaces internally as well as creating an attractive appearance to the new Balbriggan Ring Road. Internally, a central atrium, with coffered precast concrete floors and ceilings supported on elegant precast concrete circular columns create a bright, open, almost classical central space, off which the main office areas are located. The use of exposed precast concrete elements throughout, together with the extensive use of quality materials, including glazed partitions and handrails, create a relaxed, spacious environment which is both functional and pleasant to work in. The building is naturally ventilated through the central atrium and overhead rooflight. In keeping with the emphasis on reducing the environmental impact , a Geothermal system was installed to provide heating and cooling to the building. The ‘thermal mass’ of the exposed precast concrete elements was utilised to maximise energy efficiency. The use of internal linings and false ceilings were excluded at the early design stage. Coils, for heating and cooling the building were installed in the precast floor units in the office area. These coils had to be accurately installed in the units to permit on-site jointing so that the whole of the underfloor heating elements were linked together. The precast structure and floors were designed without the requirement for a structural screed and all external walls are load-bearing sandwich panels. The construction and fit-out of the 1,000m2 office took only six months. The development was constructed to a high standard of design and demonstrates the versatility and finish that can be achieved using precast concrete. Project Team

Client: Techrete Architect: JSA Architects Engineer: Clifton Scannell Emerson Quantity Surveyor: Kane Crowe Kavanagh Building Contractor: P. Elliott & Co. 50 meter span goliath gantry crane Precast Concrete: Techrete

concrete today 8 concrete today - pre-stressed beams

Concast’s New Bridge Beam Plant Concast, a long established market leader in the precast concrete sector, has expanded its range of products to provide a complete range of precast products for the civil engineering market

Bridge Borris-in-Ossory

ne of Ireland’s longest established of engineers and designers who continue substantially improved span capabilities, Oand most experienced precast to push the material limits of concrete in while maintaining concrete’s excellent companies, the Concast Precast Group, terms of longer clear-spans. Pre-stressed durability and fire resistant properties. have recently invested in a major pre- concrete beams have the advantage that Pre-stressed technology typically provides stressing special facility. The € 8m the stressed tendons are embedded in the slimmer, stronger, lighter, beams and also investment is a response to the demands concrete during manufacture, resulting in lowers the cost of the structure.

Bridge beam mould

concrete today 9 concrete today - pre-stressed beams

Pre-stressed Bridge Beams Following extensive research, the design team selected a moulding system which is heated and fully hydraulic, to speed up the de-moulding process. The high quality steel soffits of the moulds produce precast units with an impressive finish, in a wide range of bridge profiles. These include the full range of shapes including profiles such as the familiar U, TY, Y shapes etc. U-beams are one of the most widely used types, due to their attractive outline. The state of the art new facility has been fully tested and approved. The pre- stressed beams manufactured in the new facility will be used to produce bridge beams, multi-storey car parks, commercial developments, jetties and marine decks etc. Producing beams which can span up to 50m and pre- stressing loads of thousands of tonnes, the new plant is built to match the challenges of higher structures which will be required in the future.

Pre-stressing equipment

Batching plant hall

Certification and testing process A key part of the set-up of the new plant involved a rigorous testing phase, which is a (NRA) requirement. All equipment was tested and certified by independent third- parties. The proto-typing process was thorough and required substantial investment of both expertise and resources. Mott McDonald were appointed to assist in the design process. The certified systems ensure concrete strength, pre-stressing procedures, quality and standards for each unit manufactured. The indoor facility provides a high quality product, achieving high early concrete strengths. Pre-stressed bridge beams All units are manufactured in accordance with ISO standards.

concrete today 10 concrete today - pre-stressed beams

GRC Panels and Bridge Decks Concast manufactures various forms of bridge deck such as GRC panels or Omnia plate which are typically used to span the short space between bridge beams. The GRC panels are thin panels, typically with a flat or corrugated profile. The precast panels provide a permanent soffit formwork which are a practical and economical way of supporting concrete in the bridge decks. Glass Fibre Reinforced Concrete (GRC) is an innovative material, which is lightweight and flexible. These panels replace the need for temporary shuttering and hence increase the speed of construction. A thorough testing and transparent quality control procedure is required, as the units must be sufficiently durable to last throughout the lifespan of the bridge. They are also virtually maintenance free, providing a resilient fire- resistant layer on the structure, which can improve the underside finish of the bridge.

Precast Culverts Concast also provides flood control products such as box culverts with Precast box culverts associated wing walls and head beams.

N7 Motorway under construction Concast’s precast concrete range of civil projects includes items such as bridge abutment system, bridge girders, culverts, bridge decks, and ramps. The company is currently installing over 7,000 linear metres of prestressed beams, GRC panels, culverts and associated products along the N7 Castletown to Nenagh Motorway project, in conjunction with Bowen-Somague. The Bowen-Somague joint venture, is an Irish/Portuguese partnership.The finished project will include a 36km dual carriageway, to be completed by the end of 2010. Precast box culverts

The culverts are manufactured in adjustable steel moulds, which provide a quality finish. The sizes are flexible, all units are made to order in typical sizes of up to 5.2m x 5.2m. In Ireland, it is estimated that flooding causes in the order of €75m worth of damage per year. With flash flooding on the increase due to global warming, local authorities are increasingly adopting a proactive preventative strategy which includes flood control measures. The Concast Precast Group provides a full service, from design and production through to transport and installation on site. All quality documentation is provided at each stage of the project, providing the client with Precast box culverts the reassurance of production within tight quality control environment.

concrete today 11 concrete today - ’s new cable-stayed bridge

Single Concrete Pylon Supports Wate

Eugene O’Sullivan, Construction & Civil Engineering Department, Waterford Institute of Technology.

oint venture contractors, BAM (Ascon) span across the river, two back spans of arrangement from the single pylon Jand Dragados, are expected to close out 91.5m and 66.5m and end spans of 35m constructed within a reclaimed peninsula construction of the €530 million and 42m (Figure 1). on the south edge of the river. The river Waterford Bypass PPP project in the final The river span will be the longest span will provide a clearance of 14m at quarter of 2009, well ahead of the August, constructed in the , mean high water springs over the 2010 contract deadline. The centre-piece and will join on the North side navigation channel. of the project is the record-breaking 465m to Waterford on the South side of the Almost three years after start of cable-stayed bridge being constructed river. The total height of the dramatic construction in mid 2006, the cable- across the river Suir, 2km west of inverted Y pylon, from the base of the stayed bridge has reached a number of Waterford city. Designed to carry two lanes pile cap to the top of the beacon is 118m. significant milestones; the topping out of of traffic in each direction, the cable-stayed The bridge deck will be supported by the reinforced concrete pylon, the bridge will have a 230m uninterrupted steel cables radiating out in a fan-shaped erection of the majority of the composite

Figure 1: Longitudinal cross section of the bridge

concrete today 12 concrete today - waterford’s new cable-stayed bridge

Eugene O’Sullivan

rford’s New Cable-Stayed Bridge

Figure 2 contract, with a 30 year concession, to the Celtic Roads Group; comprising BAM PPP (Ascon), ACS (Spanish contractor Dragados) and NTR. Through the valued cooperation of the engineering personnel from the contractors, consulting engineers and client, the Construction & Civil Engineering Department at Waterford Institute of Technology (WIT) implemented a ‘project watch’ to monitor progress and allow students become aware of the innovative thinking and problem-solving strategies used on one of the most complex infrastructural projects ever undertaken in Ireland. The expertise gained from the project will be linked back into the undergraduate and postgraduate curricula at WIT.

Pylon foundation The combination of difficult ground conditions and the use of a single pylon design challenged the contractor in developing a radical solution for the design of the pylon foundations. Geocisa, the geotechnical division of Dragados, used a deck and the simultaneous installation complex grade-separated junctions. The rotary-bored micropiling system to and stressing of the cables. project will tie in with the M9 motorway penetrate the fragmented strata of very hard In addition to the cable-stayed bridge, from Waterford to Dublin, which is sandstone and weathered mudstone. construction is continuing apace on expected to be fully completed by the end Micropiling, not used previously on heavy 23km of dual carriageway and other link of 2010. structures in Ireland, is more associated roads, sixty other structures, including The National Roads Authority awarded with underpinning, but has been up-scaled bridges, culverts, a toll plaza and two the PPP design, build, finance and operate for use under large structures in the USA.

concrete today 13 concrete today - waterford’s new cable-stayed bridge

Figure 3: Micropile installation underlying rock and a 340mm steel cylinder (13mm wall thickness) was pushed down the full distance inside the excavated space, followed by a third steel cylinder of 178mm diameter (11mm wall thickness). The three steel cylinders were kept apart by incorporating spacer bars at 10m centres. After flushing all debris out of the borehole, a 35MPa grout was pumped into the space between the steel cylinders, to form what might be loosely described as a steel cylinder-reinforced concrete bored pile. After the 9/11 terrorist attacks in New York a similar idea has been used in the design of columns of tall buildings, whereby structural steel and reinforced concrete can be substituted by concrete filled tubes (CFT) to provide significantly greater strength. Each of the two legs of the inverted Y pylon sits on a 5m deep pilecap, which are connected by a 30m long post-tensioned tie beam; approximately 2150m3 of concrete was required for the combined pylon foundation. A 40MPa concrete, 0.45 water/cement ratio and 50% Ground Granulated Blast Furnace Slag (GGBS) was The micropiling for the pylon took place The micropiles depend largely on frictional specified, primarily to provide higher inside a bunded cofferdam in the river, bond between the pile and rock, rather durability and to control temperature in reinforced by a double line of vertical sheet than on toe resistance from the sometimes the large foundation pour. GGBS is a by- piles to prevent water ingress. weathered rock. product of the iron industry and is used as The micropiles have lengths of up to Essentially each micropile is made up of a partial replacement for cement. GGBS 35m and are socketed on average 12m into three steel cylinders, one inside the other. concrete is designed to counteract de-icing the underlying rock strata. The majority of The 410mm diameter sacrificial outer salts splashed on to the concrete surface of the micropiles are vertical, while the casing (5mm wall thickness) goes through the pylon by passing vehicles and also to be remaining piles are at an angle of 10 the soft clay of the river bed and penetrates resistant to the saline conditions of the Suir degrees, designed to resist forces during about 1m into rock (Figure 3). Further estuary. GGBS also reduces the CO2 installation of the deck and to combat wind boring was then carried out inside the content of the concrete. and transportation forces in future service. casing to approximately 12m into the Foundations’ specialist, Bachy Soletanche, piled the back supports of the bridge, using a more conventional bored piling system to Figure 4: Summary - deck erection sequence that deployed by Geocisa. Piles up to 1500mm diameter were bored to a depth of 48m with 18m rock sockets. The piles required temporary casings to support weak rock and soil. Prefabricated reinforcement cages were dropped in, extended by welding the reinforcement bars and up to 90m3 of concrete pumped in to each pile.

Bridge pylon The inverted Y-shaped pylon dominates the skyline on the approaches to Waterford city. The contractor used Doka’s SKE 50 automatic climbing formwork system, which has four different platform levels, allowing the reinforcement to be placed ahead of the concrete pouring operation (Figure 4). Climbing was done hydraulically without a crane and a lift of 4m was completed per week, with a 42m3 concrete pour achieved per pylon leg over a six hour period on the same day. The 50MPa concrete, again with 50% GGBS

concrete today 14 concrete today - waterford’s new cable-stayed bridge

mix, was initially pumped to an Figure 6: Temporary bracing approximate height of 40m and thereafter of pylon legs placed by skip, using the tower crane. Marciano Duro, Chief Surveyor, Dragados, said that setting out tolerances were very strict for the pylon and extreme care had to be taken to ensure that the profiled timber forms were dimensionally correct to adapt to the changing pylon section. The pylon from foundation to deck level is constructed of a solid reinforced concrete section; from deck level upwards the legs are hollow with a thickness of 620mm on the interior wall to 1390mm on the exterior wall. The legs of the pylon merge at a height of 66m above pile cap level. The climbing platforms had

Figure 5: Pylon mast under construction

near mid height level to minimize pylon and this required the provision of a deflection of the legs (Figure 6). pad foundation sitting on four micropiles The bridge design company, Carlos to a depth of 25m. The crane is sited in a Fernández Casado, has incorporated very exposed location in the river valley; the attractive architectural finishes into the foundation had to initially support a free pylon and the other piers supporting the standing 80m high tower crane. To service bridge. The bases of the legs of the pylon the construction of the higher part of the resemble the prow of a ship and the pylon, the crane was re-erected to an inverted Y pylon section itself has graceful intermediate height of 110m and finally to lines and curves, all of which posed a 128m, using a special long reach 500t challenge for the formwork specialists. crawler crane, similar to that used on the The contractor used a 12t Wolff tower Dublin Spire (Figure 7). At the increased crane to service the construction of the crane heights the tower crane was tied to

Figure 7

to be adapted to suit the sectional requirements of the tapering vertical 46m head of the pylon and the same formwork components were used on both the pylon legs and the pylon head (Figure 5). The Doka platforms also facilitated the construction of openings to install the sleeves for the cable anchorages. To facilitate inspection and maintenance of the cable anchorages, lifts are incorporated into one of the pylon legs and the pylon head, while there are stairs in both pylon legs and steps in the pylon head. A number of issues had to be considered in the lower pylon construction. Firstly, accurate setting out was required, due to the varying thicknesses and profiles of the pylon wall rising at 15 degrees. Secondly, as the two legs of the pylon leaned towards each other and became heavier with increasing height, a temporary horizontal bracing system had to be incorporated at

concrete today 15 concrete today - waterford’s new cable-stayed bridge

the pylon and initially proceeded over the back span, requiring the use of temporary structural steel support trestles between the piers, with spans varying between 25m and 38m. The erection of the deck over the river required more complex solutions. The contractor opted for transporting individual steel sections along the back end of the temporarily supported deck and then progressively erected the sections out over the river from the end of the completed bridge section. This required a deck based crane and a low-loader to travel over the precast concrete deck surface. The exception to this construction technique was the placing of the 85t double edge girders where Figure 8: Precast deck slabs provided by Bannager Concrete the bridge widens to 36m at the north end. The giant floating crane, Mersey Mammoth, lifted the girders into position Figure 9 on the high spring tides on two consecutive evenings in mid March, 2009 (Figure 9). The asphalting of the bridge deck, directly on to the precast slabs, will be undertaken after the cabling operations and associated heavy construction activities have been completed.

Bridge cables The function of the cables is to transfer the loads on the bridge to the foundations via the pylon (Figure 10). The cables radiate out in two planes from different levels of the pylon head in a semi-fan arrangement. In all there are 76 cables, ranging in diameter from 355mm to 455mm; the longest cable supporting the bridge is 224m and weighs 18t. Supply and installation of the cables is under the aegis of post- the pylon to counteract excessive Banagher Concrete, who also tensioning specialists MeKano4, Barcelona, overturning moments. It takes the crane manufactured precast concrete beams for while fatigue and static tests were operator up to 45 minutes to climb the 440 other bridges on the Waterford Bypass, undertaken in Zurich and Nantes. steps to his cabin in the sky. supplied the 10m x 5m x 280mm precast Raimundo Saiz Pérez, Civil Engineer, deck panels for the cable-stayed bridge Dragados, explained that each cable Bridge deck (Figure 8). Deck erection commenced at contains between 26 and 55 strands. Each The deck design is a composite steel- concrete structure, approximately 1.8m deep and 26m wide, with precast concrete panels on top of two steel edge girders connected by transverse floor beams at 5m centres. The gaps between the precast panels are stitched together with in-situ reinforced concrete. The overall design of the bridge demonstrates the effective use of steel-reinforced concrete construction. The cables and structural steel deck provide bending and tension resistance, while the reinforced concrete pylon and precast deck slab are mainly in compression. The structural steel deck units were fabricated by Fairfield Mabey in Wales, transported by low-loader/ro-ro ferry to Rosslare and then directly via the southern Figure 10 access road to the bridge site.

concrete today 16 concrete today - waterford’s new cable-stayed bridge

15mm diameter strand consists of 7 requiring an average period of three months Science degree from UCD and is a Fellow galvanized wires of prestressing steel and to consolidate the underlying weak soil. of Engineers Ireland. Eugene previously the strand is protected by wax inside a 1.5 worked on harbour, geotechnical, mm thick PE sheath. The parallel strands Multiple challenges infrastructural and gas/chemical projects in are housed in a continuous ultraviolet- Tadhg Lucey, BAM, who is joint project Spain, Libya, USA, Holland, the UK and resistant HDPE stay pipe. Apart from director with Ruben Casanova, Dragados, Ireland. providing corrosion protection, the pipe is commented that this diverse international equipped with external helical ribs, civil engineering project has thrown up designed to suppress wind and rain many technical, logistical and cultural Facts & Figures: vibration. The cables are connected at 10m challenges. Apart from the demanding site Project Statistics intervals along the deck; the lower end of conditions, the less than perfect Irish 23.1km Dual Carriageway, with 4.1km each cable goes through a steel pipe, weather and the use of innovative Link Roads connected through plates to the edge technology to simultaneously contain costs 9.6km Single Carriageway Side beams. Damping is incorporated into the and meet quality criteria, the joint venture Roads/Realignment deck anchorages. contractor has to operate within the Three principal links connection to confines of a PPP contract, manage a existing roads Innovation on the bypass culturally diverse workforce and coordinate 60 Structures including Bridges While the river crossing is the landmark the input of many designers, specialists and - 10 overbridges feature of the project, there are many other suppliers from different parts of Europe. - 8 underbridges complex and innovative structures on the The use of advanced project management - 3 underbridges for railways Waterford Bypass Project. Mark Phelan, systems enabled the contractor to more - 7 underpasses Project Manager, BAM, pointed out that effectively coordinate design information in - 1 underpass for railway the scale of geotechnical and foundations real time from various stakeholders located - 3 viaducts projects carried out are impressive. Eleven in Ireland and abroad. bridges are under construction within a The new road transportation 475m Cable Stayed River Suir Bridge 500m radius of the Grannagh Interchange, infrastructure should provide the south east 1 Toll Plaza including three bridges of 155m length and region with the platform for a revival of its a pergola design skew bridge unique to economic fortunes in these challenging River Suir Bridge Statistics Ireland. A 200m long, six-span reinforced times and the elegant cable-stayed bridge, Cable Stay Bridge carrying dual concrete viaduct consisting of 30m high in- crossing the river Suir at a historic location carriageway (D2AP) over the River Suir situ concrete piers and precast concrete U- upstream of Waterford city, is set to crossing between Waterford and beams has been constructed near become its symbolic gateway. Kilkenny. Kilmeaden over an ecologically sensitive valley (Figure 11). Acknowledgements Overall width: 30.60m Approximately 900 precast concrete The author wishes to thank Waterford JV Over length: 465m piles, 800 CFA bored piles and 90 contractors, BAM and Dragados and the Main span length: 230m (Longest span micropiles were installed to support personnel on site for their time in in 26 counties. Foyle Bridge in Derry bridges, culverts and embankments for the accommodating visits to the construction NI has a main span of 234m) complex junction at Grannagh, which site, as well as providing project Side span lengths: 40, 70, 90, (230), includes railway, road and river crossings. documentation. 35m The soil in this area consisted of a 12m Eugene O’Sullivan, Chartered Engineer Clearance over MHWS: 14m above layer of peat overlying rock, which was FIEI is a senior lecturer in the Department MHWS stabilised by inserting 500,000 metres of of Construction & Civil Engineering at Overall Tower height: 112m (above vertical geotextile band drains and applying Waterford Institute of Technology. A civil foundation) ground surcharge. Three levels of gravel engineering graduate of University College Height of Tower above road level: embankments were placed, each layer Dublin, he holds a Master of Engineering 95.6m Tower width at base: 53m Total length of cable: 11900m (approx) Diameter of cables (Outer sheath): Between 250-400mm comprising between 19 and 73 strands (Approx 550km of strand) Tower = 300t Volume of concrete: Deck = 2700m3 approx. Tower/Substructure = 4000m3 Approx. Total = 6700m3

This article first appeared in the Engineers Journal, Volume 62: Issue 10, December, 2008 and has been updated for Concrete Figure 11 Six-span viaduct at Kilmeaden Today.

concrete today 17 concrete today - new bridges at navan

O’ Reilly Concrete, Kingscourt Co. Cavan NAVAN INNER RELIEF ROAD – PHASE 2

Kingscourt and Tara Mines Bridges, O’Reilly Concrete

The Kingscourt and the Tara Mines Bridges Both bridges are a part of Navan Inner Relief Road – Phase 2 project. They are replacing two old existing railway bridges. The project started in September 2008 and is to be completed by June 2009. The bridges have been designed by Ryan Hanley WSP using standard pre-stressed bridge beams.

The Kingscourt Bridge 7 to 10 days, depending on ambient Bridge posed a greater degree of difficulty The Kingscourt bridge has been conditions. since complete demolition of an existing constructed adjacent to the existing railway The manufacture of the Kingscourt overbridge was required. Also, the new bridge. The structure is a typical solid deck Bridge beams commenced on the 13th of Tara Mines Bridge has to be built over a bridge designed using standard precast TY October 2008 and first beams were live railway. beams and concrete infill and has a clear delivered to site on the 1st of November The bridge was constructed in two span of 12.7m. The new bridge is 2008. Beams were installed using O’Reilly phases. In phase one only half width comprised of 23no. prestressed TY beams Concrete’s own 100 tonne mobile crane. abutments were poured and 12 precast and 2no. TYE edge beams, 15.3m long. The bridge deck was completed within 1 beams were placed on them. Half of the Given the very tight work programme the week. deck was completed with a finished road beam manufacturers, O’Reilly Concrete, surface and permanent parapet wall one opted to use a high strength 70N concrete The Tara Mines Bridge side and a temporary parapet on the rather than the 60N concrete required by The Tara Mines bridge is similar to the opposite side. This was done to allow one- bridge designers, so as to achieve the Kingscourt bridge in design. A total of 22 way traffic on the new road layout and to required design strength earlier than 28 no. TY5 beams and 2 no. of TYE5 edge close traffic on the old overbridge. The days. By using a high cement content beams have been used to construct the Kingscourt Bridge and the operational half combined with a high performance bridge deck. The clear span of the Tara of the Tara Mines bridge were opened for superplasticiser and curing accelerator, the Mines Bridge is 11.752m. The traffic before Christmas 2008. required concrete strength was reached after construction process of the Tara Mines Following the partial completion of the

concrete today 18 concrete today - new bridges at navan

Insitu wing walls

Insitu wing walls and precast bridge, O’Reilly Concrete

concrete today 19 concrete today - new bridges at navan

O’Reilly’s testing facilities in Taghart, Co. Cavan

Tara Mines Bridge, the old bridge was remaining 12 beams of the Tara Mines Testing demolished to make way for the new bridge Bridge were installed completing the A detailed programme of advanced tests, abutments. In February 2009 the second half of the bridge deck. including full scale load tests were carried out for these projects. To fulfil the stringent testing requirements, O’Reilly Concrete built a large rig for testing prestressed and precast beams up to 36 m span. This was carried out at O’Reilly’s testing facilities in Taghart, Co. Cavan. The tests required that a rigid foundation be poured using 200m3 of concrete for the steel testing frame. In total, four beams were tested on the rig. The quality of the concrete was monitored throughout the manufacturing process by Mattest testing agency. Cubes taken from each pour were tested for compressive strength. Additionally, insitu cores were taken from half of the beams and tested for compressive strength and quality of compaction. A compressive strength of 90 N strength was achieved on some cores – i.e. 30N greater than the design requirements. To ensure the durability of manufactured beams, the Engineers requested a permeability test. This was done with the cooperation of Queens Kingscourt and Tara Mines Bridges, O’Reilly Concrete University Belfast, on randomly chosen beams, with very good results.

concrete today 20 concrete today - thomond park re-development

Thomond Park Re-development Banagher Concrete

concrete today 21 concrete today - thomond park re-development

The €40 million Re-development of Thomond Park was completed in August 2008, in time to host an epic inaugural match between Munster and the legendary ‘All Blacks’. With a capacity of 26,000 (15,000 seated and 11,000 terraced) the facility contains 2 large suites with a seating capacity of 500 and 200 respectively, 20 corporate boxes, a bar with standing room for 1,000 and a number of smaller suites with a seating capacity for between 30 and 60 people.

riginally designed as an all steel including a raker-beam system that installed steel starter bars. The columns Ostructure, a ‘last minute would meet all design criteria. were propped, levelled and grouted into substitution’ brought Banagher concrete Another key challenge posed by the place. A total of eighteen precast concrete into the frame, with Precast columns and client’s brief was that although the main panels 7.35m long and 1.1m high, each beams substituting the original steel stands were to be demolished, the playing weighing 5 tonnes, were then placed frame. This change in specification was pitch could not be interfered with and the between the columns and grouted to dictated by the client brief which existing standing terraces were to be kept concrete pads. A ten step terrace was then specified that the structure be designed open for games. This part of the brief was placed on the precast wall running down to to accommodate pop concerts which, it facilitated and a number of rugby games a lower level pad foundation to form the transpired, could not be practically done were played with parts of the construction West terrace. To complete the terrace in steel due to the excessive design and installation of Precast elements backdrop, a total of twenty back panels loading. Banagher Concrete, who had completed prior to scheduled games. were installed between the upper level originally tendered to supply Precast The first phase of the project required columns, together with gable walls, concrete terraced seating, together with the construction of a new standing terrace vomitary walls and vomitary stairs. Due to Markus Hausen of Exstrado Consulting on the West side of the pitch. This the introduction of Precast concrete Engineers (Cape Town, South Africa), consisted of twenty columns 6.5m high, elements, the first phase of the construction devised the precast concrete frame, placed on pad foundations with pre- was completed in half the time it would

Thomond Park re-development

concrete today 22 concrete today - thomond park re-development

Thomond Park re-development have taken if in-situ concrete had been A total of four hundred tie-beams and the stand to rapidly take shape. Over used, allowing Munster’s crucial Heineken spine-beams (17m max. length) were eight hundred precast concrete terrace Cup games to proceed as scheduled. placed onto the columns, levelled and units, weighing up to 8.5 tonnes were Production of the Precast concrete grouted into place. Again, this fast-track installed, including parapet units, elements for the East Stand started in mid type of construction requires that beams vomitary walls, vomitary stairs and infill June 2007 with the first elements arriving be in place for only twenty four hours steps. Several types of terrace units were on site in the last week of July. Production prior to loading with floor units. The produced, some with a sunken step near of elements for the West stand started in spine beams were manufactured in such a the vomitarys. Towards the back of the August and deliveries commenced in mid way that the floor slab could sit into a stand the riser height is increased to September. The main contractor prefabricated boot on the beam. Once the improve spectator sight lines. prepared pad foundations, complete with floor slabs were poured, the structure was Delivery of the Precast elements for projecting steel starter-bars, in effectively tied together and functioning the two main stands took place between preparation for the arrival of the first as one structural unit. July 2007 and May 2008. Considering precast columns. Columns were rapidly The next stage was the erection of the scale and complexity of the project, erected at a rate of twelve per day and concrete raker-beams which carry the the use of Precast concrete elements and once levelled needed only twenty four precast terrace/step units. Raker-beams highly experienced Precast manufacturers hours to set before spine-beams and tie- were grouted in place on top of columns Banagher Concrete, were critical factors beams could be placed. which had projecting starter-bars to in the timely and successful resolution of A total of one hundred and thirty five receive the raker. Due to the long-span the brief. columns were Precast in different requirements, two raker-beams were dimensions and shapes: placed side by side and bolted together using large steel plates cast into the ends Project Principals Precast Column Types of the beams. This joint, each of which a) 500mm x 350mm (rectangular with required sixteen steel bolts, occurred at Main Conctractor: P.J.Hegarty integral corbel) sixteen different locations in each stand. Consulting Engineers: Michael Punch b) 500mm, 500mm (square with integral A total of seventy two beams were cast, & Ptns. corbel) the heaviest weighing over twenty Architects: Murray O’ Laoire c) 500mm and 850mm (semi-circular no tonnes. Planning: AFL corbel) With the raker-beams in place and Precast Manufacturer: Banagher d) 500mm x 1050mm (semi – circular no grouted, the installation of Precast Concrete Ltd. corbel) concrete terrace units began, allowing

concrete today 23 Irish Concrete Federation, 8 Newlands Business Park, Road, Clondalkin, Dublin 22 Tel: 01 464 0082 Fax: 01 464 0087 E-Mail: [email protected] Web: www.irishconcrete.ie