Operational temperatures of all-weather thoroughbred racetracks influence surface functional properties. (May 2020)

• Record Type: Journal Article
• Authors: Northrop, Alison J.; Martin, Jaime H.; Holt, Danielle; Hobbs, Sarah J.
• Is Part Of: Biosystems engineering. Volume 193(2020)
• Page Start: 37
• Page End: 45
• Publication Date: 2020-05
• Subjects: operational temperatures -- shear resistance -- impact firmness -- horse hoof-surface-interaction -- functional properties; OBST Orono biomechanical surface tester -- GWTT Glen Withy torque tester -- DSC differential scanning calorimetry; Bioengineering -- Periodicals; Agricultural engineering -- Periodicals; Biological systems -- Periodicals; Génie rural -- Périodiques; Systèmes biologiques -- Périodiques; 631
• DOI: 10.1016/j.biosystemseng.2020.02.003
• Languages: English
• ISSNs: 1537-5110

Abstract

Abstract : The surface temperature of all-weather racetracks has previously been correlated to speed. However specific functional properties such as grip, cushioning and impact firmness have not been directly compared to environmental conditions. The objective of this study was to assess how temperature influences functional properties of racetracks, and categorise surface wax binders according to first thermal transition peak, and compare responses at different operational temperatures. Functional properties were determined for UK all-weather racetrack surfaces (n = 6) using mechanical testing equipment which assess the loads experienced by the forelimb at gallop (randomised block design). Tests were carried out using latex lined moulds, embedded within a test box with a predefined boundary at 0 °C, 20 °C and 40 °C. Wax binders underwent differential scanning calorimetry to identify thermal transition peaks. Changes in operational temperatures significantly influenced surface responses when a wax binder was part of the composition. Temperature was a factor that significantly contributed to the variation found in horizontal grip ( F 2, 237 = 65.69, P < 0.001), cushioning ( F 2, 237 = 58.24, P < 0.001), impact firmness ( F 2, 237 = 28.02, P < 0.001) and rotational grip ( F 1 2, 65 = 9.45, P < 0.001). Using a test box meant individual racetracks were generalised but this enabled conditions to be controlled. Colder temperatures demonstrated higher surface hardness and shear resistance that may increase risk of musculoskeletal injury although this was not measured here. Awareness of the effect temperature has on specific track behaviour allows maintenance protocols to be further developed to improve consistency when temperatures change, with the aim of improving safety. Highlights: Functional properties of UK racetracks alter during normal operational temperatures. Greater variation in track cushioning and hardness was seen at lower temperatures. Repeated drops akin to used-tracks produced higher hardness at lower temperatures. Individual first thermal transition peak influences track response to temperature. A first thermal transition peak <40 °C showed greater range of hardness and grip.