Concrete is an incredibly versatile material with numerous applications in not only structural engineering but also as an architectural and practical material for use in furniture, acoustics and recreation.

This year students from across New Zealand will have the opportunity to push the boundaries for the application of concrete even further by designing, building and competing with a cricket bat made from concrete at the Concrete NZ Conference.

1. GENERAL RULES

1.1 Participants
Each team should consist of between 2-4 members. Membership in the team is open to any university student or person involved in the concrete industry. For student entries, advice and assistance may be provided by others but the leadership and management of the work and any presentations if applicable must be by the students. Additional members can be part of the team for the game. Remember this a friendly game!

1.2 Transport & Removal
The participating organizations are responsible for the transportation of the cricket bat to the competition and the removal of the cricket bat and any components/debris from the venue.

2. CRICKET BAT REQUIREMENTS

There are two components required for the cricket bat competition:

1. Two cricket bats are required for each team. The requirements are provided below.
2. One standard concrete cylinder dia 100 mm, length 200 mm, of the material used to cast the cricket bat is required for testing at the time of the conference. The ends can either be ground or capped.

2.1 Dimensional & Mass Requirements
The bat shall meet the following specifications, based on Law 5 of the laws of cricket (Figure 1):

• Overall length of the bat including handle shall not be more than 96.52 cm.
• The blade shall not exceed Width 11.0 cm, Depth 6.8 cm, Edges 4.1 cm.
• The handle shall not exceed 52% of the overall length of the bat.
• A protective covering that is not rigid, either at the time of its application to the blade or subsequently, may be placed on surfaces. The maximum thickness of the covering is 0.1 cm.

Dimensions of Aperture
Total depth: 2.68 in / 6.8 cm
Width: 4.33 in / 11.0 cm
Edge: 1.61 in / 4.1 cm
Curve: 0.20 in / 0.5 cm
Note: The curve of the lower edge of the aperture is an arc of a circle of radius 12.0 in/30.5 cm, whose centre is on the vertical line of the aperture.

2.2 Concrete Materials
The bat can be constructed from any form of cementitious binder system combined with aggregate that forms a mortar or concrete. There are no restrictions on the type or size/grading of aggregate used.

The blade must contain at least 50% concrete/mortar by volume.

Intentionally entrained air or void spaces are permitted.

2.3 Reinforcing
The cricket bat must be reinforced. Any type of reinforcing material, including fibres, are permitted.

2.4 Handle
The handle and blade of the cricket bat can either be cast as one component or separately and joined together. The handle must also contain at least 50% concrete/mortar by volume.

3. COMPETITION PROCESS

The competition will run during the Concrete NZ Conference and include an oral presentation, cylinder test, bat evaluation, and cricket match.

3.1 Oral Presentation
Prior to the match each team will have the opportunity to making a brief presentation about their bat. This should highlight the design and any innovations and summarize the construction process. The oral presentation will be used to help judge the bat evaluation criteria.

3.2 Bat Evaluation
The overall design, construction and appearance of the cricket bats and the quality of the work will be evaluated. A sample assessment sheet is provided in the Appendix below.

Evaluation will include the measured compressive strength of the cylinder which will be tested at the conference. The cylinder will be weighed, measured and loaded to determine its maximum compressive strength, with points awarded based on the highest ratio of compressive strength/mass (MPa/kg).

Teams are encouraged to consider low-carbon materials as part of the design, which may contribute to the design and innovation scores. Furthermore, a 10% bonus in total score will be given to the team that demonstrates the lowest embodied carbon mix or binder.

3.3 Cricket Match
A friendly cricket match (likely 8-12 overs for each side) will be played at or near the conference using the cricket bats. A soft rubber or indoor ball will be used for the competition. Further details including health and safety information will be provided. Rules will be similar to indoor/action cricket.

3.4 Evaluation & Scoring:

4. PRIZE

The winning team will take home a trophy, framed certificate and the satisfaction of have designed, built and competed with the best concrete cricket bat in Aotearoa New Zealand!

5. KEY DATES

• Confirmation of team involvement 15 August
• Bat evaluation and match 16 October (match TBC)
• Presentation 17 October

6. REGISTRATION OF INTEREST

Could those considering entering the competition please register your interest with the Learned Society Convenor - Adam Leach (adam@concretenz.org.nz).

These competition details can be downloaded as a pdf here.