Third generation artificial grass pitches have been observed to get harder over time. The maintenance technique of rubber infill decompaction is intended to help slow, or reverse, this process. At present, little is understood about either the science of the infill compaction process or the efficacy of decompaction maintenance. The objective of this study was to measure the changes in rubber infill net bulk density, force reduction (impact absorption) and vertical ball rebound under various levels of compactive effort in controlled laboratory-based testing. The assessments were repeated after the systems had been raked to simulate the decompaction maintenance techniques. These tests defined the limits of compaction (loose to maximally compacted) in terms of the change in rubber infill net bulk density, force reduction and vertical ball rebound. Site testing was also undertaken at four third generation pitches immediately pre and post decompaction, to determine the measurable effects in the less well controlled field environment. Rubber infill net bulk density was found to increase as compactive effort increased, resulting in increased hardness. Decompacting the surface was found to approximately fully reverse these effects. In comparison, the site measurements demonstrated similar but notably smaller magnitudes of change following the decompaction process suggesting that the field state pre and post decompaction did not reach the extremes obtained in the laboratory. The findings suggest that rubber infill net bulk density is an important parameter influencing the hardness of artificial grass and that decompactions can be an effective method to reverse compaction related hardness changes.

中文翻译：

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了解解压维护对第三代人造草坪的填充状态和游戏性能的影响

已经观察到第三代人造草坪球场随着时间的推移变得越来越坚硬。橡胶填充分解的维护技术旨在帮助减缓或逆转这一过程。目前，人们对填充压实过程的科学或解压维护的功效知之甚少。本研究的目的是在基于实验室的受控测试中测量不同压实力水平下橡胶填充物的净堆积密度、力减少（冲击吸收）和垂直球回弹的变化。在系统被倾斜以模拟解压维护技术后重复评估。这些测试根据橡胶填充物净堆积密度、力降低和垂直球回弹的变化定义了压实极限（松散到最大压实）。在解压前后立即在四个第三代沥青上进行现场测试，以确定在控制较差的现场环境中的可测量效果。发现橡胶填充物的净堆积密度随着压实力的增加而增加，导致硬度增加。发现对表面进行解压可以大致完全逆转这些影响。相比之下，现场测量表明在解压过程后发生了相似但明显更小的变化，这表明解压前和解压后的现场状态没有达到实验室中获得的极端值。研究结果表明，橡胶填充物的净堆积密度是影响人造草硬度的重要参数，并且解压可以是一种有效的方法来逆转压实相关的硬度变化。