Development of Practical and Cost-Effective Ultra-High-Performance Engineered Cementitious Composites Using Natural Sand and No Silica Fume

Abstract

The objective of this study was to evaluate the feasibility of developing practical and cost-effective ultra-high-performance engineered cementitious composites (UHP-ECCs) using natural river sand and no silica fume (SF). Fresh and hardened properties of composites utilizing river sand, with and without SF, and incorporating 1.5 and 2 vol% (volume percent) ultra-high-molecular-weight polyethylene fibers were evaluated. Furthermore, matrix and fiber/matrix interface properties were investigated. Experimental results showed that the inclusion of SF generally produced negative impacts in the mechanical strength (i.e., compressive, tensile, and flexural) and ductility of the composites, which was mainly attributed to a worsening fiber dispersion. This was supported by the loss in workability observed when increasing fiber content or implementing SF. Clear tendencies in the effect of fiber content on the mechanical strength of the composites were not observed. However, increment in fiber content decreased the tensile ductility of the materials, presumably because of poor fiber dispersion. All the mixtures evaluated exhibited pseudo strain-hardening (PSH) behavior and ECC-like ductility, which was supported by the PSH strength and energy indexes obtained, which exceeded the minimum recommended values for robust PSH behavior. Practical and cost-effective UHP-ECC materials (i.e., cementitious composites simultaneously exhibiting compressive strength >120 MPa and tensile strain capacity >2%) using natural river sand and no SF were successfully developed, which to the authors’ knowledge was achieved for the first time.

Influence of Stone Processing Waste on Mechanical, Durability, and Ecological Performance of Hybrid Fiber-Reinforced Engineered Cementitious Composite

“…In the last few years, several researchers have used polyethylene (PE) and PVA fiber to reinforce the ECC. The hydrophobically natured high-modulus PE fiber does not sustain any chemical bond with the cement matrix; however, it exhibits frictional bonding, which significantly enhances the complementary energy of fiber bridging (13)(14)(15). PE is also known as ultra-high-molecular-weight polyethylene (UHMWPE) as it has extremely long chains, with a molecular mass usually between 3.5 and 7.5 million amu (16).…”

“…The introduction of low and high-modulus fibers in hybridizations such as PVA and steel, polypropylene (PP) and PVA, and PE and steel resulted in better shear strength, deflection capacity, energy absorption capacity, impact resistance, tensile strength, and fiber bridging capability (13)(14)(15)(20)(21)(22)(23)(24)(25). Recently, notable research works have been conducted on cement-based products with the dispersion of several types of fibers such as steel, basalt, nylon, glass, textile, carbon, bagasse, PP, polyester (PET), PE, PVA, and so forth, to improve the behavior of the cement matrix.…”