Flexural Strength Characteristics of Compacted Cement-Polypropylene Fiber Sand: Fid-Bau Portal

Flexural Strength Characteristics of Compacted Cement-Polypropylene Fiber Sand

Jamsawang, Pitthaya / Voottipruex, Panich / Horpibulsuk, Suksun

An improvement of flexural strength of cement stabilized sand using polypropylene fibers designated as compacted cement-polypropylene fiber-sand (CCFS) is investigated in this research. The studied material performance of the CCFS includes postpeak behavior, toughness, and equivalent flexural strength ratio. The fiber inclusion significantly improves the postpeak flexural behavior, which is a requirement for bound pavement materials. The first peak flexural strength $f_{1}$ and stiffness of both compacted-cement-sand (CCS) and CCFS are essentially the same for the same cement content. For low fiber content, the fiber inclusion primarily prevents the sudden failure. The CCFS exhibits deflection-hardening behavior and the peak flexural strength ( $f_{p}$ ) is higher than the first peak flexural strength ( $f_{1}$ ) for medium to high fiber contents. Two modes of failure are noted: single failure plane and stress transfer–induced multiple cracks. For low to medium fiber contents, the single failure plane is observed for both deflection-softening and deflection-hardening behaviors. The high fiber contents of 2% can significantly distribute the load to different parts of the test beam; hence, multiple cracks are observed even at a large failure deflection, without a clear single failure plane. The fiber inclusion has been proven as suitable for the bound pavement CCFS material in both the failure mode and the flexural properties. These improvements are of practical significance in pavement performance and design.