NEW STANDARD PRECAST CONCRETE BRIDGE …

1 Transfund New Zealand Research Report No. [..] NEW STANDARD PRECAST CONCRETE BRIDGE BEAMS Stage 1 Research & Identify Proposed STANDARD Beam Shapes and Spans Alex Gray & Phil Gaby, Beca Carter Hollings & Ferner Ltd Geoff Brown & Donald Kirkcaldie, Opus International Consultants Ross Cato & Paul Sweetman, PRECAST New Zealand ISSN .. Keywords: STANDARD PRECAST CONCRETE BRIDGE beams New Zealand. 2003, Transfund New Zealand PO Box 2331, Lambton Quay, Wellington, New Zealand Telephone 64-4-473-0220; Facsimile 64-4-499-0733 An Important Note for the Reader The research detailed in this report was commissioned by Transfund New Zealand Transfund New Zealand is a Crown entity established under the Transit New Zealand Act 1989.

2 Its principal objective is to allocate resources to achieve a safe and efficient roading system. Each year, Transfund New Zealand invests a portion of its funds on research that contributes to this objective. While this report is believed to be correct at the time of its preparation, Transfund New Zealand, and its employees and agents involved in the preparation and publication, cannot accept any liability for its contents or for any consequences arising from its use. People using the contents of the document should apply, and rely upon, their own skill and judgement. They should not rely on its contents in isolation from other sources of advice and information. The report is only made available on the basis that all users of it, whether direct or indirect, must take appropriate legal or other expert advice in relation to their own circumstances.

3 They must rely solely on their own judgement and seek their own legal or other expert advice in relation to the use of this report. The material contained in this report is the output of research and should not be construed in any way as policy adopted by Transfund New Zealand but may form the basis of future policy. CONTENTS Executive summary Abstract 1 INTRODUCTION .. 8 2 REVIEW OF CURRENT SITUATION IN NEW ZEALAND .. 9 Background 9 Existing STANDARD BRIDGE Beams 9 Issues to be Addressed with the Existing STANDARD BRIDGE Beams 12 Other Beam Sections Currently Used in New Zealand 12 3 LITERATURE REVIEW OF CURRENT INTERNATIONAL PRACTICE .. 14 General 14 Australia 14 General .. 14 Australian Beam Shapes and Practice .. 14 United Kingdom 16 General.

4 16 United Kingdom Beam Shapes and Practice .. 16 North American Practice 17 General .. 17 North American Beam Shapes and 20 Summary of Literature Review Findings 21 4 SURVEY OF NEW ZEALAND PRECAST PRESTRESSED BRIDGE BEAM MANUFACTURERS .. 24 General 24 Survey Methodology 24 Survey Results 24 Interpretation of results 25 Span/depth ratios .. 25 5 INDUSTRY CONSULTATION AND PARTICIPATION .. 27 General 27 Industry Group 27 Industry Consultation Workshops 27 Summary of Consultation 28 6 ANALYSIS OF RESEARCH RESULTS .. 29 General 29 Preferred STANDARD Beam Shapes 29 Criteria for Selecting New STANDARD Beam Shapes 29 Selection of New Beam Shapes 32 Review of Existing STANDARD Beam Shapes.

5 33 Review of Other Beam Shapes Currently Used in New 34 Review of Beam Shapes Currently Used 34 Selection of Beam Shapes .. 36 New STANDARD Beam Shapes Proposed .. 37 7 PRELIMINARY DESIGN OF NEW BEAM SHAPES .. 40 General 40 Criteria for a STANDARD BRIDGE Superstructure 40 Hollow Core Beams 42 General .. 42 Span Range and Unit 42 Width of Units .. 42 Void Shape .. 43 CONCRETE Strength .. 44 Transverse Design .. 44 Longitudinal Joints Between Units .. 45 Maintenance 46 Summary of Findings .. 46 I Beams 47 General .. 47 Beam Spacing .. 47 Beam Shape .. 47 CONCRETE Strength.

6 48 Edge Protection Requirements .. 48 48 Summary of Findings .. 49 Super-T Beams 49 General .. 49 Span Range for the various depths of 49 Flange Width and Beam Spacing .. 50 Top slab Depth .. 50 CONCRETE Strength .. 50 50 Edge Protection .. 51 51 Maintenance .. 51 Overall Summary 51 8 COST ESTIMATES AND ECONOMIC ANALYSIS .. 52 General 52 Cost Estimates for New Beam Shapes 52 Economic Assessment of New Beam Shapes 53 Summary of Findings .. 53 9 CONCLUSIONS AND RECOMMENDATIONS .. 54 Conclusions 54 Recommendations 54 APPENDICES Appendix 1: International Literature Review Appendix 2: Survey Details of New Zealand PRECAST Prestressed BRIDGE Beam Manufacturers 6 EXECUTIVE SUMMARY The objective of Stage 1 of this research project was to research and identify the most appropriate PRECAST CONCRETE BRIDGE beam shapes that should be adopted as industry standards for the future.

7 This research was considered a priority as the STANDARD BRIDGE beam designs currently used in New Zealand were adopted as industry standards in the 1970 s. These designs are almost 30 years old and out of date with respect to design codes, construction techniques and the higher strength materials now commonly used. As well as reviewing current New Zealand practice the researchers did a literature survey of STANDARD beam usage in Australia, North America and the United Kingdom. Also, many precasters of BRIDGE beams in New Zealand contributed data to a survey. From this survey information and statistics were produced to indicate the most popular beam shapes currently in use. Extensive consultation of a wide range of industry participants was a crucial part of the research process.

8 Workshops were held in three main centres to allow all sectors of the industry to raise and discuss issues. This included a poll of participants to select a new beam shape. From the research above and consultation comments a range of beam selection criteria were then developed to identify the key criteria that needed to be addressed in any future designs. The most important criteria was the inclusion of the BRIDGE superstructure in the STANDARD BRIDGE beam series of drawings. The research team concluded that for cost and practicality reasons that a STANDARD BRIDGE superstructure should be developed to limit the range of spans and cross section widths for the new BRIDGE beams. The beam shapes recommended for new detailed designs by the research team are the existing hollow core deck units for spans up to both 18 and 25 metres and the existing I beams for spans up to 32 metres.

9 The new shape proposed is the Super-T beam for spans up to 30 metres. 7 ABSTRACT The objective of Stage 1 of this research project (carried out from July 2002 to March 2003) was to research and identify the most appropriate PRECAST CONCRETE BRIDGE beam shapes that should be adopted as industry standards for the future. This research was considered a priority as the STANDARD BRIDGE beam designs currently used in New Zealand were adopted as industry standards in the 1970 s. These designs are almost 30 years old and out of date with respect to design codes, construction techniques and the higher strength materials now commonly used. The researchers carried out a literature survey of STANDARD beam usage in Australia, North America and the United Kingdom along with a survey of current New Zealand practice.

10 Following a survey of BRIDGE beam precasters and three consultation workshops a range of key beam selection criteria were developed that needed to be addressed in any future designs. The researchers recommended that full designs for two existing beam shapes (hollow core and I beam) and one new shape (Super-T) be carried out in the second stage of the project. 8 1 INTRODUCTION In the mid 1970 s the Ministry of Works (MOW) designed a range of twin hollow-core, I and U PRECAST CONCRETE BRIDGE beams and small span bridges which were adopted as New Zealand industry standards . These STANDARD designs led to cost efficiencies both in design time and also the use of STANDARD moulds by precasters led to more competitive tenders for supply of BRIDGE beams. Probably thousands of these STANDARD beams were used in bridges all over New Zealand during the next 20 years.