Effect of recycled steel fibers on the mechanical strength and impact toughness of precast paving blocks

Abstract

Owing to high density, concrete paving blocks (CPB) are highly brittle when subjected to occasional impact loads. Fractures in CPB create riding discomfort and increase maintenance costs. This issue demands the engineering design of CPB suitable for occasional dynamic loadings. Therefore, this study explores the effect of eco-friendly and cheap fiber recycled from scrape tire steel on the performance of paving blocks. For this purpose, several CPB batches were prepared and studied with the varying contents of recycled tire steel fiber (RTSF). The studied properties included density, water absorption, ultrasonic pulse velocity (UPV), compressive strength, flexural strength, and impact toughness. It was shown that RTSF caused nominal changes in the compressive strength of CPB. However, it was highly useful in enhancing the flexural strength and impact toughness of CPB. At 0.5% volume fraction RTSF, flexural strength and impact toughness of plain CPB were increased by 42% and 271%, respectively. RTSF incorporation can prolong the life of CPB pavements and can help in preserving riding comfort.

Keywords

• Recycling
• Fiber reinforcement
• Heavy traffic
• Precast blocks
• Compressive strength
• Fracture toughness