close up, top down view of a mixture of different types of polypropylene and steel fibers for concrete structural reinforcement

abstract addition background bars building bundle bundled close closeup colored concrete construction crimped different down end extreme fibers fibrillated fibrillation flat gray grey hooked industrial industry lay macro material metal micro plastic polyethylene polymer polymeric polypropylene reinforced reinforcement reinforcing sinusoidal steel structural supplement synthetic texture textured top twist twisted types view white